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THE SCIENCE OF CLIMATE CHANGE

Below you will find a series of informative articles from various scientific sources on the topic of Climate Change
The material is being provided by GreeningUSA, --  www.greeningusa.org 

"No government can continue good but under the control of the people; and . . . . their minds are to be informed by education what is right and what wrong; to be encouraged in habits of virtue and to be deterred from those of vice . . . . These are the inculcations necessary to render the people a sure basis for the structure and order of government."
Thomas Jefferson


Canadian Arctic Glacier Melt Accelerating, Irreversible, Projections Suggest



http://www.sciencedaily.com/releases/2013/03/130312134914.htm

Mar. 12, 2013 ­ Ongoing glacier loss in the Canadian high Arctic is accelerating and probably irreversible, new model projections by Lenaerts et al. suggest. The Canadian high Arctic is home to the largest clustering of glacier ice outside of Greenland and Antarctica -- 146,000 square kilometers (about 60,000 square miles) of glacier ice spread across 36,000 islands.

In the past few years, the mass of the glaciers in the Canadian Arctic archipelago has begun to plummet. Observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites suggest that from 2004 to 2011 the region's glaciers shed approximately 580 gigatons of ice. Aside from glacier calving, which plays only a small role in Canadian glacier mass loss, the drop is due largely to a shift in the surface-mass balance, with warming-induced meltwater runoff outpacing the accumulation of new snowfall.

Using a coupled atmosphere-snow climate model, the authors reproduced the observed changes in glacier mass and sought to forecast projected changes given a future of continued warming. Driving the model with a climate reanalysis dataset for the period 1960 to 2011 and with a potential future warming pathway, the authors find that their model accurately reproduces observed glacier mass losses, including a recent up-tick in the rate of the ice's decline.

The authors calculate that by 2100, when the Arctic archipelago is 6.5 Kelvin (14 degrees Fahrenheit) warmer, the rate of glacier mass loss will be roughly 144 gigatons per year, up from the present rate of 92 gigatons per year. In total, the researchers expect Canadian Arctic archipelago glaciers to lose around 18 percent of their mass by the end of the century. Given current warming trends, they suggest that the ongoing glacier loss is effectively irreversible.
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The above story is reprinted from materials provided by American Geophysical Union, via EurekAlert!, a service of AAAS.

Journal Reference:
  1. Jan T. M. Lenaerts, Jan H. van Angelen, Michiel R. van den Broeke, Alex S. Gardner, Bert Wouters, Erik van Meijgaard. Irreversible mass loss of Canadian Arctic Archipelago glaciers. Geophysical Research Letters, 2013; DOI: 10.1002/grl.50214

More Storms Like Sandy? Arctic Ice Loss Amplified Superstorm Sandy Violence



http://www.sciencedaily.com/releases/2013/03/130305145133.htm

Mar. 5, 2013 ­ If you believe that last October's Superstorm Sandy was a freak of nature -- the confluence of unusual meteorological, atmospheric and celestial events -- think again.

Cornell and Rutgers researchers report in the March issue of Oceanography that the severe loss of summertime Arctic sea ice -- attributed to greenhouse warming -- appears to enhance Northern Hemisphere jet stream meandering, intensify Arctic air mass invasions toward middle latitudes, and increase the frequency of atmospheric blocking events like the one that steered Hurricane Sandy west into the densely populated New York City area.

The article, "Superstorm Sandy: A Series of Unfortunate Events?" was authored by Charles H. Greene, Cornell professor of earth and atmospheric sciences and director of Cornell's Ocean Resources and Ecosystems program; Jennifer A. Francis of Rutgers University's Institute of Marine and Coastal Sciences; and Bruce C. Monger, Cornell senior research associate, earth and atmospheric sciences.

The researchers assert that the record-breaking sea ice loss from summer 2012, combined with the unusual atmospheric phenomena observed in late October, appear to be linked to global warming.

A strong atmospheric, high-pressure blocking pattern over Greenland and the northwest Atlantic prevented Hurricane Sandy from steering northeast and out to sea like most October hurricanes and tropical storms from the Caribbean. In fact, Sandy traveled up the Atlantic coast and turned left "toward the most populated area along the eastern seaboard" and converged with an extratropical cyclone; this, in turn, fed the weakening Hurricane Sandy and transformed it into a monster tempest.

Superstorm Sandy's extremely low atmospheric pressure and the strong high-pressure block to the north created violent east winds that pushed storm surge against the eastern seaboard. "To literally top it off, the storm surge combined with full-moon high tides and huge ocean waves to produce record high water levels that exceeded the worst-case predictions for parts of New York City," write the researchers.

Greene, Francis and Monger add: "If one accepts this evidence and . . . takes into account the record loss of Arctic sea ice this past September, then perhaps the likelihood of greenhouse warming playing a significant role in Sandy's evolution as an extratropical superstorm is at least as plausible as the idea that this storm was simply a freak of nature."


Story Source:

The above story is reprinted from materials provided by Cornell University. The original article was written by Blaine Friedlander.

Sunlight Stimulates Release of Climate-Warming Gas from Melting Arctic Permafrost



http://www.sciencedaily.com/releases/2013/02/130211162116.htm

Feb. 11, 2013 ­ Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.

University of Michigan ecologist and aquatic biogeochemist George Kling and his colleagues studied places in Arctic Alaska where permafrost is melting and is causing the overlying land surface to collapse, forming erosional holes and landslides and exposing long-buried soils to sunlight.

They found that sunlight increases bacterial conversion of exposed soil carbon into carbon dioxide gas by at least 40 percent compared to carbon that remains in the dark. The team, led by Rose Cory of the University of North Carolina, reported its findings in an article to be published online Feb. 11 in the Proceedings of the National Academy of Sciences.

"Until now, we didn't really know how reactive this ancient permafrost carbon would be -- whether it would be converted into heat-trapping gases quickly or not," said Kling, a professor in the U-M Department of Ecology and Evolutionary Biology. EEB graduate student Jason Dobkowski is a co-author of the paper.

"What we can say now is that regardless of how fast the thawing of the Arctic permafrost occurs, the conversion of this soil carbon to carbon dioxide and its release into the atmosphere will be faster than we previously thought," Kling said. "That means permafrost carbon is potentially a huge factor that will help determine how fast the Earth warms."

Tremendous stores of organic carbon have been frozen in Arctic permafrost soils for thousands of years. If thawed and released as carbon dioxide gas, this vast carbon repository has the potential to double the amount of the heat-trapping greenhouse gas in the atmosphere on a timescale similar to humanity's inputs of carbon dioxide due to the burning of fossil fuels.

That creates the potential for a positive feedback: As Earth warms due to the human-caused release of heat-trapping gases into the atmosphere, frozen Arctic soils also warm, thaw and release more carbon dioxide. The added carbon dioxide accelerates Earth's warming, which further accelerates the thawing of Arctic soils and the release of even more carbon dioxide. Recent climate change has increased soil temperatures in the Arctic and has thawed large areas of permafrost. Just how much permafrost will thaw in the future and how fast the carbon dioxide will be released is a topic of heated debate among climate scientists.

Already, the melting of ground ice is causing land-surface subsidence features called thermokarst failures. A thermokarst failure is generated when ice-rich, permanently frozen soils are warmed and thawed. As the ice melts, the soil collapses and either creates an erosional hole in the tundra or -- if the slope is steep enough -- a landslide.

Thermokarst failures change the trajectory of the debate on the role of the Arctic in global climate, according to Kling and his colleagues. The unanticipated outcome of the study reported in PNAS is that soil carbon will not be thawed and degraded directly in the soils. Instead, the carbon will be mixed up and exposed to sunlight as the land surface fails.

Sunlight -- and especially ultraviolet radiation, the wavelengths that cause sunburn -- can degrade the organic soil carbon directly to carbon dioxide gas, and sunlight can also alter the carbon to make it a better food for bacteria. When bacteria feed on this carbon, they respire it to carbon dioxide, much the same way that people respire carbon in food and exhale carbon dioxide as a byproduct.

"Whether UV light exposure will enhance or retard the conversion of newly exposed carbon from permafrost soils has been, until recently, anybody's guess," said University of North Carolina's Cory, the study's lead author. "In this research, we provide the first evidence that the respiration of previously frozen soil carbon will be amplified by reactions with sunlight and their effects on bacteria."

"We know that in a warmer world there will be more of these thermokarst failures, and that will lead to more of this ancient frozen carbon being exposed to surface conditions," Kling said. "While we can't say how fast this Arctic carbon will feed back into the global carbon cycle and accelerate climate warming on Earth, the fact that it will be exposed to light means that it will happen faster than we previously thought."

The researchers analyzed water from seven thermokarst failures near Toolik Lake, Alaska, as well as 27 other undisturbed sites nearby.

In addition to Cory, Kling and Dobkowski, Byron Crump of the University of Maryland was a co-author of the PNAS paper. The research was supported by several grants from the National Science Foundation.
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The above story is reprinted from materials provided by University of Michigan.

Northeast U.S. Sees Second Driest November in More Than a Century

http://www.sciencedaily.com/releases/2012/12/121205142325.htm

ScienceDaily (Dec. 5, 2012) ­ Even though Hurricane Sandy helped create wet start to the month for several states, November 2012 went into the record books as the second-driest November since 1895 in the Northeast. With an average of 1.04 inches or precipitation, the region received only 27 percent of its normal level.

The record driest November was 1917 when the Northeast received only 0.88 inches of precipitation.

All states were drier than average. Departures ranged from 16 percent of normal in Connecticut, their second-driest November, to 37 percent of normal in New Jersey, their 11th driest. Of the remaining states, New Hampshire, Vermont and West Virginia had their second-driest November; Delaware, Maine, Maryland and New York had their third driest. Pennsylvania, Rhode Island and Massachusetts also ranked in the top 10 driest Novembers.

Overall for autumn, the Northeast was slightly drier than average with 11.36 inches of precipitation (98 percent of normal). The region was split down the middle with half of the states drier and half the states wetter than normal. Connecticut took the title of driest state with only 78 percent of normal, while Delaware led the wet states with 120 percent of normal.

The latest U.S. Drought Monitor, issued Nov. 27, indicated abnormal dryness continued in upstate New York while a new area of abnormal dryness popped up near the Vermont-New Hampshire border and in central-southern West Virginia.

In addition to being dry, the Northeast was cooler than normal for November -- in spite of a brief mind-month warmup. With an average temperature of 37.2 degrees, it was 2.5 degrees cooler than normal and was the coolest November since 1997. All states reported below average temperatures for the first time since October 2009. West Virginia and Maine were the coolest at 4.1 degrees below average. Departures for the rest of the states ranged from 4 degrees below normal in New Jersey to 0.9 degrees below normal in Vermont.

Autumn's overall average temperature of 50 degrees was average for November in the Northeast. West Virginia was the coolest at 1.6 degrees below average for the season. Of the warm states, Vermont was the warmest at 1.1 degrees above average.

Story Source:
The above story is reprinted from materials provided by Cornell University.

Record High for Global Carbon Emissions

http://www.sciencedaily.com/releases/2012/12/121202164059.htm

ScienceDaily (Dec. 2, 2012) ­ Global carbon dioxide (CO2) emissions are set to rise again in 2012, reaching a record high of 35.6 billion tonnes -- according to new figures from the Global Carbon Project, co-led by researchers from the Tyndall Centre for Climate Change Research at the University of East Anglia (UEA).

The 2.6 per cent rise projected for 2012 means global emissions from burning fossil fuel are 58 per cent above 1990 levels, the baseline year for the Kyoto Protocol.

This latest analysis by the Global Carbon Project is published December 2 in the journal Nature Climate Change with full data released simultaneously by the journal Earth System Science Data Discussions.

It shows the biggest contributors to global emissions in 2011 were China (28 per cent), the United States (16 per cent), the European Union (11 per cent), and India (7 per cent). (My addition. Not part of this article - Pete Wirth. I thought these pop. figures might be helpful.  China's pop. 1,347,350,000 December 31, 2011, 19.09% of world's pop.,  US. pop. 314,873,000 December 3, 2012,  4.46% of world's pop., India's pop.1,210,193,422 March 1, 2011, 17.15% of world's population.)

Emissions in China and India grew by 9.9 and 7.5 per cent in 2011, while those of the United States and the European Union decreased by 1.8 and 2.8 per cent.

Emissions per person in China of 6.6 tonnes of CO2 were nearly as high as those of the European Union (7.3), but still below the 17.2 tonnes of carbon used in the United States. Emissions in India were lower at 1.8 tonnes of carbon per person.

Prof Corinne Le Quéré, director of the Tyndall Centre for Climate Change Research and professor at UEA, led the publication of the data. She said: "These latest figures come amidst climate talks in Doha. But with emissions continuing to grow, it's as if no-one is listening to the entire scientific community."

The 2012 rise further opens the gap between real-world emissions and those required to keep global warming below the international target of two degrees.

"I am worried that the risks of dangerous climate change are too high on our current emissions trajectory. We need a radical plan," added Prof Corinne Le Quéré.

The analysis published in Nature Climate Change shows significant emission reductions are needed by 2020 to keep two degrees as a feasible goal.

It shows previous energy transitions in Belgium, Denmark, France, Sweden, and the UK have led to emission reductions as high as 5 per cent each year over decade-long periods, even without climate policy.

Lead author Dr Glen Peters, of the Centre for International Climate and Environmental Research in Norway, said: "Scaling up similar energy transitions across more countries can kick-start global mitigation with low costs. To deepen and sustain these energy transitions in a broad range of countries requires aggressive policy drivers."

Co-author Dr Charlie Wilson, of the Tyndall Centre at UEA, added: "Public policies and institutions have a central role to play in supporting the widespread deployment of low carbon and efficient energy-using technologies, and in supporting innovation efforts."

Emissions from deforestation and other land-use change added 10 per cent to the emissions from burning fossil fuels. The CO2 concentration in the atmosphere reached 391 parts per million (ppm) at the end of 2011.

These results lends further urgency to recent reports that current emissions pathways are already dangerously high and could lead to serious impacts and high costs on society. These other analyses come from the International Energy Agency, the United Nations Environment Programme, the World Bank, the European Environment Agency, and PricewaterhouseCoopers.

Story Source:
The above story is reprinted from materials provided by University of East Anglia, via AlphaGalileo.
Journal References:
  1. Glen P. Peters, Robbie M. Andrew, Tom Boden, Josep G. Canadell, Philippe Ciais, Corinne Le Quéré, Gregg Marland, Michael R. Raupach, Charlie Wilson. The challenge to keep global warming below 2 °C. Nature Climate Change, 2012; DOI: 10.1038/nclimate1783
  2. C. Le Quéré, R. J. Andres, T. Boden, T. Conway, R. A. Houghton, J. I. House, G. Marland, G. P. Peters, G. van der Werf, A. Ahlström, R. M. Andrew, L. Bopp, J. G. Canadell, P. Ciais, S. C. Doney, C. Enright, P. Friedlingstein, C. Huntingford, A. K. Jain, C. Jourdain, E. Kato, R. F. Keeling, K. Klein Goldewijk, S. Levis, P. Levy, M. Lomas, B. Poulter, M. R. Raupach, J. Schwinger, S. Sitch, B. D. Stocker, N. Viovy, S. Zaehle, N. Zeng. The global carbon budget 1959–2011. Earth System Science Data Discussions, 2012; 5 (2): 1107 DOI: 10.5194/essdd-5-1107-2012

Sea Levels Rising Faster Than IPCC Projections

http://www.sciencedaily.com/releases/2012/11/121128093911.htm

ScienceDaily (Nov. 27, 2012) ­ Sea levels are rising 60 per cent faster than the Intergovernmental Panel on Climate Change's (IPCC) central projections, new research suggests.

While temperature rises appear to be consistent with the projections made in the IPCC's fourth assessment report (AR4), satellite measurements show that sea levels are actually rising at a rate of 3.2 mm a year compared to the best estimate of 2 mm a year in the report.

The researchers, from the Potsdam Institute for Climate Impact Research, Tempo Analytics and Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, believe that findings such as these are important for keeping track of how well past projections match the accumulating observational data, especially as projections made by the IPCC are increasingly being used in decision making.

The study, which has been published November 28, in IOP Publishing's journal Environmental Research Letters, involved an analysis of global temperatures and sea-level data over the past two decades, comparing them both to projections made in the IPCC's third and fourth assessment reports.

Results were obtained by taking averages from the five available global land and ocean temperature series.

After removing the three known phenomena that cause short-term variability in global temperatures -- solar variations, volcanic aerosols and El Nino/Southern Oscillation -- the researchers found that the overall warming trend at the moment is 0.16°C per decade, which closely follows the IPCC's projections.

Satellite measurements of sea levels showed a different picture, however, with current rates of increase being 60 per cent faster than the IPCC's AR4 projections.

Satellites measure sea-level rise by bouncing radar waves back off the sea surface and are much more accurate than tide gauges as they have near-global coverage; tide gauges only sample along the coast. Tide gauges also include variability that has nothing to do with changes in global sea level, but rather with how the water moves around in the oceans, such as under the influence of wind.

The study also shows that it is very unlikely that the increased rate is down to internal variability in our climate system and also shows that non-climatic components of sea-level rise, such as water storage in reservoirs and groundwater extraction, do not have an effect on the comparisons made.

Lead author of the study, Stefan Rahmstorf, said: "This study shows once again that the IPCC is far from alarmist, but in fact has under-estimated the problem of climate change. That applies not just for sea-level rise, but also to extreme events and the Arctic sea-ice loss."

Story Source:
The above story is reprinted from materials provided by Institute of Physics.
Journal Reference:
  1. Stefan Rahmstorf, Grant Foster, Anny Cazenave. Comparing climate projections to observations up to 2011. Environmental Research Letters, 2012; 7 (4): 044035 DOI: 10.1088/1748-9326/7/4/044035

This is the document referred to in the article Four-Degrees Briefing for the World Bank: The Risks of a Future Without Climate Policy ScienceDaily (Nov. 19, 2012)

The 84-page document,
http://climatechange.worldbank.org/sites/default/files/Turn_Down_the_heat_Why_a_4_degree_centrigrade_warmer_world_must_be_avoided.pdf  

“Turn Down the Heat: Why a 4°C  (7.2 degrees Fahrenheit)  Warmer World Must Be Avoided,” was written for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics and published last week.

" The 4°C scenarios are devastating: the inundation of coastal cities; increasing risks for food production potentially leading to higher malnutrition rates; many dry regions becoming dryer, wet regions wetter; unprecedented heat waves in many regions, especially in the tropics; substantially exacerbated water scarcity in many regions; increased frequency of high-intensity tropical cyclones; and irreversible loss of biodiversity, including coral reef systems," Dr. Jim Yong Kim President, World Bank Group.

© 2012 International Bank for Reconstruction and Development / The World Bank
1818 H Street NW
Washington DC 20433
Telephone: 202-473-1000
Internet:
www.worldbank.org

Four-Degrees Briefing for the World Bank: The Risks of a Future Without Climate Policy
http://www.sciencedaily.com/releases/2012/11/121119104842.htm

ScienceDaily (Nov. 19, 2012) — Humankind's emissions of greenhouse gases are breaking new records every year. Hence we're on a path towards 4-degree global warming probably as soon as by the end of this century. This would mean a world of risks beyond the experience of our civilization -- including heat waves, especially in the tropics, a sea-level rise affecting hundreds of millions of people, and regional yield failures impacting global food security. These are some of the results of a report for the World Bank, conducted by the Potsdam Institute for Climate Impact Research (PIK) and Climate Analytics in Berlin. The poorest in the world are those that will be hit hardest, making development without climate policy almost impossible, the researchers conclude.

"The planetary machinery tends to be jumpy, this is to respond disproportionately to disruptions that come with the manmade greenhouse effect," PIK's director Hans Joachim Schellnhuber points out. "If we venture far beyond the 2-degree guardrail, towards 4 degrees, we risk crossing tipping points in the Earth system." This could be the case with coral reefs which face collapse under unabated global warming, or with the Greenland ice sheet. To melt the ice sheet would take thousands of years, yet this might be an irreversible process that could start soon. "The only way to avoid this is to break with the fossil-fuel-age patterns of production and consumption," says Schellnhuber.

Climate impacts: Heat waves, sea-level rise, yield failures

Already today impacts of climate change are observed. The Russian heat wave in 2010, according to preliminary estimates, produced a death toll of several thousand, annual crop failure of about 25%, and economic losses of about US$15 billion. Extreme events like this at 4 degrees global warming would become "the new normal" in some parts of the world, according to the report. In the tropics, the coolest months at the end of the century are likely to be substantially warmer than the warmest months today.

Sea level, under this scenario, would rise by 50 to 100 centimeters within this century, and more so in coming centuries. The rate of rise varies from one region to the other, depending on sea currents and other factors. Projections suggest that sea-level rise will be strongest in countries like the Philippines, Mexico, and India.

Within economic sectors, too, tipping effects with rapidly increasing damages can occur, for instance in agriculture. Already, observations showed that important cereals are sensitive to temperature increases passing certain thresholds, resulting in large-scale yield failure. Changes in the water cycle can aggravate this, when droughts occur or flooding affects farmed land.

World Bank President Kim: "A 4-degree warmer world can, and must be, avoided"

"The report draws from the current state of science and delivers new analysis of heat waves and regional sea-level rise, so of course there remain some uncertainties," says William Hare, co-founder of Climate Analytics in Berlin and guest scientist at PIK. "We work with that by defining risk as potential damage multiplied with the probability -- a rather improbable event can be a great risk if its impacts are huge."

World Bank President Jim Yong Kim who was nominated early this year by US President Barack Obama and assumed his new position in July, has personally been briefed on the 4-degrees report by Schellnhuber some weeks ago in Washington D.C.. "A 4-degree warmer world can, and must be, avoided -- we need to hold warming below 2 degrees," President Kim now said in a statement. "Lack of action on climate change threatens to make the world our children inherit a completely different world than we are living in today. Climate change is one of the biggest single challenges facing development, and we need to assume the moral responsibility to take action on behalf of future generations, especially the poorest."

--------------------------------------------------------------------------------
Story Source:

The above story is reprinted from materials provided by Potsdam Institute for Climate Impact Research (PIK).

Glaciers Cracking in the Presence of Carbon Dioxide




http://www.sciencedaily.com/releases/2012/10/121010191749.htm

ScienceDaily (Oct. 10, 2012) ­ The well-documented presence of excessive levels of carbon dioxide (CO2) in our atmosphere is causing global temperatures to rise and glaciers and ice caps to melt.

New research, published October 11, in IOP Publishing's Journal of Physics D: Applied Physics, has shown that CO2 molecules may be having a more direct impact on the ice that covers our planet.

Researchers from the Massachusetts Institute for Technology have shown that the material strength and fracture toughness of ice are decreased significantly under increasing concentrations of CO2 molecules, making ice caps and glaciers more vulnerable to cracking and splitting into pieces, as was seen recently when a huge crack in the Pine Island Glacier in Antarctica spawned a glacier the size of Berlin.

Ice caps and glaciers cover seven per cent of Earth -- more than Europe and North America combined -- and are responsible for reflecting 80-90 per cent of the Sun's light rays that enter our atmosphere and maintain Earth's temperature. They are also a natural carbon sink, capturing a large amount of CO2.

"If ice caps and glaciers were to continue to crack and break into pieces, their surface area that is exposed to air would be significantly increased, which could lead to accelerated melting and much reduced coverage area on the Earth. The consequences of these changes remain to be explored by the experts, but they might contribute to changes of the global climate," said lead author of the study Professor Markus Buehler.

Buehler, along with his student and co-author of the paper, Zhao Qin, used a series of atomistic-level computer simulations to analyse the dynamics of molecules to investigate the role of CO2 molecules in ice fracturing, and found that CO2 exposure causes ice to break more easily.

Notably, the decreased ice strength is not merely caused by material defects induced by CO2 bubbles, but rather by the fact that the strength of hydrogen bonds -- the chemical bonds between water molecules in an ice crystal -- is decreased under increasing concentrations of CO2. This is because the added CO2 competes with the water molecules connected in the ice crystal.

It was shown that CO2 molecules first adhere to the crack boundary of ice by forming a bond with the hydrogen atoms and then migrate through the ice in a flipping motion along the crack boundary towards the crack tip.

The CO2 molecules accumulate at the crack tip and constantly attack the water molecules by trying to bond to them. This leaves broken bonds behind and increases the brittleness of the ice on a macroscopic scale.

Story Source:

The above story is reprinted from materials provided by Institute of Physics, via EurekAlert!, a service of AAAS.
Journal Reference:
  1. Zhao Qin and Markus J Buehler. Carbon dioxide enhances fragility of ice crystals. J. Phys. D: Appl. Phys., 2012 DOI: 10.1088/0022-3727/45/44/445302

Glacial Thinning Has Sharply Accelerated at Major South American Icefields

http://www.sciencedaily.com/releases/2012/09/120905110537.htm

ScienceDaily (Sep. 5, 2012) ­ For the past four decades scientists have monitored the ebbs and flows of the icefields in the southernmost stretch of South America's vast Andes Mountains, detecting an overall loss of ice as the climate warms. A new study, however, finds that the rate of glacier thinning has increased by about half over the last dozen years in the Southern Patagonian Icefield, compared to the 30 years prior to 2000.

"Patagonia is kind of a poster child for rapidly changing glacier systems," said Michael Willis, lead author of the study and a research associate at Cornell University in Ithaca, New York. "We are characterizing a region that is supplying water to sea level at a big rate, compared to its size." The Southern Patagonian Icefield together with its smaller northern neighbor, the Northern Patagonian Icefield, are the largest icefields in the southern hemisphere -- excluding Antarctica. The new study shows that the icefields are losing ice faster since the turn of the century and contributing more to sea level rise than ever before.

Earlier studies determined that between the 1970's and 2000 both icefields, which feed into surrounding oceans as they melt, together raised global sea levels by an average of .042 millimeters each year. Since 2000, Willis and his colleagues found that number increased to 0.067 mm of sea level rise on average per year -- about two percent of total annual sea level rise since 1998.

The Southern Icefield, which Willis and his colleagues focused on, loses around 20 billion tons (gigatonnes) of ice each year, the scientists calculated, which is roughly 9,000 times the volume of water stored by Hoover Dam annually. Cumulatively, the Southern Patagonian Icefield has lost enough water over the last 12 years to cover the entire United States with 2.7 centimeters (about 1 inch) of water. Include melting of both icefields, and that amount increases to 3.3 centimeters (1.2 inches), the scientists report.

The collaborative study between scientists from Cornell University and the Center for Scientific Studies (CECs) in Valdivia, Chile, is set to be published 5 September in Geophysical Research Letters, a journal of the American Geophysical Union.

To map the changing Southern Patagonian Icefield, Willis and his colleagues collected information from two different satellite missions. Using 156 satellite images taken over the 12-year period by NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and data from the Shuttle Radar Topography Mission, the scientists mapped how the Southern Patagonian Icefield changed in height and overall size between February 2000 and March 2012.

The team compared its findings with a different set of observations from twin satellites known as the Gravity Recovery and Climate Experiment (GRACE).

"Using ASTER, we think that we have a good idea of where things are changing. But with GRACE we get a good idea of when things are changing. So we have this powerful hybrid," Willis said. From their new map, the scientists identified individual glaciers and how much each has thinned -- i.e. shrunk in height -since 2000. On average, the Southern Patagonian Icefield glaciers have thinned by about 1.8 meters (5.9 feet) per year.

"We find some glaciers are stagnant and even that some have advanced slightly but on the whole, retreat and thinning is prevalent," Willis said. "Interestingly, we see thinning occurring up to the highest elevations, where presumably it is coldest."

Warming air temperatures contribute to the thinning at the highest and coldest regions of the ice field, Willis said. Moreover warmer temperatures mean greater chances that rain, as opposed to snow, will fall on and around the glaciers. This double threat of warming and more rain may, in turn, change the amount of water beneath the glaciers. More water means less friction, so the glaciers start to move faster as they thin, moving even more ice in to the oceans. Rising lakes at the front of the glaciers may also play a part as they eat away at the icy edges faster, causing the glaciers to retreat even further.

"Precipitation is a huge component and likely causes large changes in mass input, and therefore net balance," said Alex Gardner, an assistant professor at Clark University in Worcester, Massachusetts, who was not involved with the study but studies glaciers and ice sheets. "[This new research] shows very high rates of mass loss and it would be great to see a follow up study on how lakes modify these rates of loss."

Even though scientists have yet to understand exactly how warming temperatures will continue to influence these South American icefields, this new study provides valuable information for future predictions, Gardner said.

"A study like this really provides a strong data set to validate and calibrate glacial models that we could then use to simulate future changes in glaciers," he said. "Modeling is really the only tool we have to provide future predictions."
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The above story is reprinted from materials provided by American Geophysical Union.
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Journal Reference:
  1. Michael J. Willis, Andrew K. Melkonian, Matthew E. Pritchard, and Andrés Rivera. Ice loss from the Southern Patagonian Ice Field, South America, between 2000 and 2012. Geophysical Research Letters, 2012; DOI: 10.1029/2012GL053136, 2012

Arctic Sea Ice Reaches Lowest Extent Ever Recorded

http://www.sciencedaily.com/releases/2012/08/120827130726.htm

ScienceDaily (Aug. 27, 2012) ­ The blanket of sea ice floating on the Arctic Ocean melted to its lowest extent ever recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder's National Snow and Ice Data Center.

On Aug. 26, the Arctic sea ice extent fell to 1.58 million square miles, or 4.10 million square kilometers. The number is 27,000 square miles, or 70,000 square kilometers below the record low daily sea ice extent set Sept. 18, 2007. Since the summer Arctic sea ice minimum normally does not occur until the melt season ends in mid- to late September, the CU-Boulder research team expects the sea ice extent to continue to dwindle for the next two or three weeks, said Walt Meier, an NSID scientist.

"It's a little surprising to see the 2012 Arctic sea ice extent in August dip below the record low 2007 sea ice extent in September," he said. "It's likely we are going to surpass the record decline by a fair amount this year by the time all is said and done."

On Sept. 18, 2007, the September minimum extent of Arctic sea ice shattered all satellite records, reaching a five-day running average of 1.61 million square miles, or 4.17 million square kilometers. Compared to the long-term minimum average from 1979 to 2000, the 2007 minimum extent was lower by about a million square miles -- an area about the same as Alaska and Texas combined, or 10 United Kingdoms.

While a large Arctic storm in early August appears to have helped to break up some of the 2012 sea ice and helped it to melt more quickly, the decline seen in in recent years is well outside the range of natural climate variability, said Meier. Most scientists believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases pumped into Earth's atmosphere.

CU-Boulder researchers say the old, thick multi-year ice that used to dominate the Arctic region has been replaced by young, thin ice that has survived only one or two melt seasons -- ice which now makes up about 80 percent of the ice cover. Since 1979, the September Arctic sea ice extent has declined by 12 percent per decade.

The record-breaking Arctic sea ice extent in 2012 moves the 2011 sea ice extent minimum from the second to the third lowest spot on record, behind 2007. Meier and his CU-Boulder colleagues say they believe the Arctic may be ice-free in the summers within the next several decades.

"The years from 2007 to 2012 are the six lowest years in terms of Arctic sea ice extent in the satellite record," said Meier. "In the big picture, 2012 is just another year in the sequence of declining sea ice. We have been seeing a trend toward decreasing minimum Arctic sea ice extents for the past 34 years, and there's no reason to believe this trend will change."

The Arctic sea ice extent as measured by scientists is the total area of all Arctic regions where ice covers at least 15 percent of the ocean surface, said Meier.

Scientists say Arctic sea ice is important because it keeps the polar region cold and helps moderate global climate -- some have dubbed it "Earth's air conditioner." While the bright surface of Arctic sea ice reflects up to 80 percent of the sunlight back to space, the increasing amounts of open ocean there -- which absorb about 90 percent of the sunlight striking the Arctic -- have created a positive feedback effect, causing the ocean to heat up and contribute to increased sea ice melt.

Earlier this year, a national research team led by CU embarked on a two-year effort to better understand the impacts of environmental factors associated with the continuing decline of sea ice in the Arctic Ocean. The $3 million, NASA-funded project led by Research Professor James Maslanik of aerospace engineering sciences includes tools ranging from unmanned aircraft and satellites to ocean buoys in order to understand the characteristics and changes in Arctic sea ice, including the Beaufort Sea and Canada Basin that are experiencing record warming and decreased sea ice extent.

NSIDC is part of CU-Boulder's Cooperative Institute for Research in Environmental Sciences -- a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration headquartered on the CU campus -- and is funded primarily by NASA. NSIDC's sea ice data come from the Special Sensor Microwave Imager/Sounder sensor on the Defense Meteorological Satellite Program F17 satellite using methods developed at NASA's Goddard Space Flight Center in Greenbelt, Md.

Story Source:

The above story is reprinted from materials provided by University of Colorado at Boulder.

Climate Change Will Have Profound Effects On Northeast U.S. Forests, Report Says

http://www.sciencedaily.com/releases/2012/08/120815175049.htm

ScienceDaily (Aug. 15, 2012) ­ A new report by U.S. and Canadian scientists analyzes decades of research and concludes that the climate of the Northeast has changed and is likely to change more. The report outlines the effects of climate change on multiple aspects of forests in the northeastern corner of the United States and eastern Canada and concludes with recommendations on adaptive and mitigating strategies for dealing with future effects.

The report, "Changing Climate, Changing Forests: The impacts of climate change on forests of the northeastern United States and eastern Canada," brings together science on all aspects of forest health, from changes in the water cycle to changes in trees, wildlife and nuisance species. The report focuses on established science and offers recommendations for decision-makers on steps that will make forests more resilient to the effects of climate change.

"Nothing is certain about climate change except that it poses a tremendous challenge to forests," according to Michael T. Rains, Director of the Forest Service's Northern Research Station. "Forest Service science is developing tools such at this report that will inform decision-making and contribute to making the nation's forests more resilient to changing conditions."

The region covered by the report includes seven states in the United States -- Maine, New York, Vermont, New Hampshire, Massachusetts, Connecticut and Rhode Island -- and the Canadian provinces of Quebec, Labrador, Newfoundland, New Brunswick, and Nova Scotia. The report stems from the work of Northeast Forests 2100 Initiative, a coalition of 38 U.S. and Canadian scientists. Results of Northeast Forests 2100 research were published in a series of papers in the Canadian Journal of Forest Research in 2009.

As part of the Northeast Forests 2100 project, scientists examined the influence of climate change on the forests of the Northeast using historic records, experimental studies, and computer models, and found linkages between climate and the basic functioning of the region's forests. Scientists concluded that climate change will have profound effects on Northeast forests with the accelerating rate of climate change and the associated stresses that climate change generates.

"The quantity of information available about climate change sometimes makes it hard to find information that is relevant to a particular region," according to Lindsey Rustad, a team leader and research ecologist with the Northern Research Station. "Our intent was to create a credible go-to source of science on the effects of a changing climate on Northeastern forests." The report concludes with recommended adaptive and mitigating measures that could help sustain forest health and make forests more resistant to the effects of a changing climate.

The NE Forests 2100 initiative has been supported by grants from the Northeastern States Research Cooperative (NSRC) and by organizing efforts of the Northeastern Ecosystem Research Cooperative (NERC). The development of "Changing Climate, Changing Forests" was supported by the U.S. Forest Service, Northern Research Station and the New York State Energy Research and Development Authority (NYSERDA).

Published by the U.S. Forest Service as General Technical Report NRS-99, it is available at: http://nrs.fs.fed.us/pubs/41165

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The above story is reprinted from materials provided by USDA Forest Service - Northern Research Station.

Extreme Weather Linked to Global Warming, Nobel Prize-Winning Scientist Says
http://www.sciencedaily.com/releases/2012/08/120820114041.htm

ScienceDaily (Aug. 20, 2012) — New scientific analysis strengthens the view that record-breaking summer heat, crop-withering drought and other extreme weather events in recent years do, indeed, result from human activity and global warming, Nobel Laureate Mario J. Molina, Ph.D., said at a conference in Philadelphia on August 20.

Molina, who shared the 1995 Nobel Prize in Chemistry for helping save the world from the consequences of ozone depletion, presented the keynote address at the 244th National Meeting & Exposition of the American Chemical Society.

"People may not be aware that important changes have occurred in the scientific understanding of the extreme weather events that are in the headlines," Molina said. "They are now more clearly connected to human activities, such as the release of carbon dioxide ? the main greenhouse gas ? from burning coal and other fossil fuels."

Molina emphasized that there is no "absolute certainty" that global warming is causing extreme weather events. But he said that scientific insights during the last year or so strengthen the link. Even if the scientific evidence continues to fall short of the absolute certainly measure, the heat, drought, severe storms and other weather extremes may prove beneficial in making the public more aware of global warming and the need for action, said Molina.

"It's important that people are doing more than just hearing about global warming," he said. "People may be feeling it, experiencing the impact on food prices, getting a glimpse of what everyday life may be like in the future, unless we as a society take action."

Molina, who is with the University of California, San Diego, suggested a course of action based on an international agreement like the Montreal Protocol that phased out substances responsible for the depletion of the ozone layer.

"The new agreement should put a price on the emission of greenhouse gases, which would make it more economically favorable for countries to do the right thing. The cost to society of abiding by it would be less than the cost of the climate change damage if society does nothing," he said.

In the 1970s and 1980s, Molina, F. Sherwood Rowland, Ph.D., and Paul J. Crutzen, Ph.D., established that substances called CFCs in aerosol spray cans and other products could destroy the ozone layer. The ozone layer is crucial to life on Earth, forming a protective shield high in the atmosphere that blocks potentially harmful ultraviolet rays in sunlight. Molina, Rowland and Crutzen shared the Nobel Prize for that research. After a "hole" in that layer over Antarctica was discovered in 1985, scientists established that it was indeed caused by CFCs, and worked together with policymakers and industry representatives around the world to solve the problem. The result was the Montreal Protocol, which phased out the use of CFCs in 1996.

Adopted and implemented by countries around the world, the Montreal Protocol eliminated the major cause of ozone depletion, said Molina, and stands as one of the most successful international agreements. Similar agreements, such as the Kyoto Protocol, have been proposed to address climate change. But Molina said these agreements have largely failed.

Unlike the ozone depletion problem, climate change has become highly politicized and polarizing, he pointed out. Only a small set of substances were involved in ozone depletion, and it was relatively easy to get the small number of stakeholders on the same page. But the climate change topic has exploded. "Climate change is a much more pervasive issue," he explained. "Fossil fuels, which are at the center of the problem, are so important for the economy, and it affects so many other activities. That makes climate change much more difficult to deal with than the ozone issue."

In addition to a new international agreement, other things must happen, he said. Scientists need to better communicate the scientific facts underlying climate change. Scientists and engineers also must develop cheap alternative energy sources to reduce dependence on fossil fuels.

Molina said that it's not certain what will happen to Earth if nothing is done to slow down or halt climate change. "But there is no doubt that the risk is very large, and we could have some consequences that are very damaging, certainly for portions of society," he said. "It's not very likely, but there is some possibility that we would have catastrophes."
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Story Source:

The above story is reprinted from materials provided by American Chemical Society (ACS).


July 2012 Marked Hottest Month On Record for Contiguous U.S.; Drought Expands to Cover Nearly 63 Percent of the Lower 48

http://www.sciencedaily.com/releases/2012/08/120808115055.htm

ScienceDaily (Aug. 8, 2012) ­ According to NOAA scientists, the average temperature for the contiguous U.S. during July was 77.6°F, 3.3°F above the 20th century average, marking the hottest July and the hottest month on record for the nation. The previous warmest July for the nation was July 1936 when the average U.S. temperature was 77.4°F. The warm July temperatures contributed to a record-warm first seven months of the year and the warmest 12-month period the nation has experienced since record keeping began in 1895.

During July, the contiguous U.S. averaged a precipitation total of 2.57 inches, which was 0.19 inch below average. Near-record dry conditions were present for the middle of the nation, with the drought footprint expanding to cover nearly 63 percent of the Lower 48, according the U.S. Drought Monitor, while some areas such as the Gulf Coast and the Southwest had wetter-than-average conditions.

This monthly analysis (summary, full report) from NOAA's National Climatic Data Center is part of the suite of climate services NOAA provides government, business and community leaders so they can make informed decisions.

U.S. climate highlights -- July
Drought conditions update
Year-to-date (January-July)
12-month period (August 2011-July 2012)
Additional information can be found on the following web sites: Story Source:
The above story is reprinted from materials provided by National Oceanic and Atmospheric Administration.

Chronic 2000-04 Drought, Worst in 800 Years, May Be the 'New Normal'

http://www.sciencedaily.com/releases/2012/07/120729142137.htm

ScienceDaily (July 29, 2012) ­ The chronic drought that hit western North America from 2000 to 2004 left dying forests and depleted river basins in its wake and was the strongest in 800 years, scientists have concluded, but they say those conditions will become the "new normal" for most of the coming century.

Such climatic extremes have increased as a result of global warming, a group of 10 researchers reported July 29 in Nature Geoscience. And as bad as conditions were during the 2000-04 drought, they may eventually be seen as the good old days.

Climate models and precipitation projections indicate this period will actually be closer to the "wet end" of a drier hydroclimate during the last half of the 21st century, scientists said.

Aside from its impact on forests, crops, rivers and water tables, the drought also cut carbon sequestration by an average of 51 percent in a massive region of the western United States, Canada and Mexico, although some areas were hit much harder than others. As vegetation withered, this released more carbon dioxide into the atmosphere, with the effect of amplifying global warming.

"Climatic extremes such as this will cause more large-scale droughts and forest mortality, and the ability of vegetation to sequester carbon is going to decline," said Beverly Law, a co-author of the study, professor of global change biology and terrestrial systems science at Oregon State University, and former science director of AmeriFlux, an ecosystem observation network.

"During this drought, carbon sequestration from this region was reduced by half," Law said. "That's a huge drop. And if global carbon emissions don't come down, the future will be even worse."

This research was supported by the National Science Foundation, NASA, U.S. Department of Energy, and other agencies. The lead author was Christopher Schwalm at Northern Arizona University. Other collaborators were from the University of Colorado, University of California at Berkeley, University of British Columbia, San Diego State University, and other institutions.

It's not clear whether or not the current drought in the Midwest, now being called one of the worst since the Dust Bowl, is related to these same forces, Law said. This study did not address that, and there are some climate mechanisms in western North America that affect that region more than other parts of the country.

But in the West, this multi-year drought was unlike anything seen in many centuries, based on tree ring data. The last two periods with drought events of similar severity were in the Middle Ages, from 977-981 and 1146-1151. The 2000-04 drought affected precipitation, soil moisture, river levels, crops, forests and grasslands.

Ordinarily, Law said, the land sink in North America is able to sequester the equivalent of about 30 percent of the carbon emitted into the atmosphere by the use of fossil fuels in the same region. However, based on projected changes in precipitation and drought severity, scientists said that this carbon sink, at least in western North America, could disappear by the end of the century.

"Areas that are already dry in the West are expected to get drier," Law said. "We expect more extremes. And it's these extreme periods that can really cause ecosystem damage, lead to climate-induced mortality of forests, and may cause some areas to convert from forest into shrublands or grassland."

During the 2000-04 drought, runoff in the upper Colorado River basin was cut in half. Crop productivity in much of the West fell 5 percent. The productivity of forests and grasslands declined, along with snowpacks. Evapotranspiration decreased the most in evergreen needleleaf forests, about 33 percent.

The effects are driven by human-caused increases in temperature, with associated lower soil moisture and decreased runoff in all major water basins of the western U.S., researchers said in the study.

Although regional precipitations patterns are difficult to forecast, researchers in this report said that climate models are underestimating the extent and severity of drought, compared to actual observations. They say the situation will continue to worsen, and that 80 of the 95 years from 2006 to 2100 will have precipitation levels as low as, or lower than, this "turn of the century" drought from 2000-04.

"Towards the latter half of the 21st century the precipitation regime associated with the turn of the century drought will represent an outlier of extreme wetness," the scientists wrote in this study.

These long-term trends are consistent with a 21st century "megadrought," they said.

Story Source:

The above story is reprinted from materials provided by Oregon State University, via Newswise.

Journal Reference:
  1. Christopher R. Schwalm, Christopher A. Williams, Kevin Schaefer, Dennis Baldocchi, T. Andrew Black, Allen H. Goldstein, Beverly E. Law, Walter C. Oechel, Kyaw Tha Paw U, Russel L. Scott. Reduction in carbon uptake during turn of the century drought in western North America. Nature Geoscience, 2012; DOI: 10.1038/NGEO1529

Climate Change Linked to Ozone Loss: May Result in More Skin Cancer

http://www.sciencedaily.com/releases/2012/07/120726142204.htm

ScienceDaily (July 26, 2012) ­ For decades, scientists have known that the effects of global climate change could have a potentially devastating impact across the globe, but Harvard researchers say there is now evidence that it may also have a dramatic impact on public health.

As reported in a paper published in the July 27 issue of Science, a team of researchers led by James G. Anderson, the Philip S. Weld Professor of Atmospheric Chemistry, are warning that a newly-discovered connection between climate change and depletion of the ozone layer over the U.S. could allow more damaging ultraviolet (UV) radiation to reach the Earth's surface, leading to increased incidence of skin cancer.

In the system described by Anderson and his team, water vapor injected into the stratosphere by powerful thunderstorms converts stable forms of chlorine and bromine into free radicals capable of transforming ozone molecules into oxygen. Recent studies have suggested that the number and intensity of such storms are linked to climate changes, Anderson said, which could in turn lead to increased ozone loss and greater levels of harmful UV radiation reaching the Earth's surface, and potentially higher rates of skin cancer.

"If you were to ask me where this fits into the spectrum of things I worry about, right now it's at the top of the list," Anderson said. "What this research does is connect, for the first time, climate change with ozone depletion, and ozone loss is directly tied to increases in skin cancer incidence, because more ultraviolet radiation is penetrating the atmosphere."

Unfortunately, Anderson said, we don't know how this process will evolve over time.

"We don't know what the development of this has been -- we don't have measurements of this deep convective injection of water into the stratosphere that go back in time," Anderson said.

"But the best guide for the evolution of this is to look at the research that connects climate change with severe storm intensity and frequency, and it's clear that there is a developing scientific case that the addition of carbon dioxide to the atmosphere is increasing climate change, and in turn driving severe storm intensity and frequency."

While it's impossible to know how many skin cancer cases may be related to ozone depletion over the U.S., the link between ozone loss and increased incidence of the disease has been extensively studied, Anderson said.

"There has been a major effort by the medical community to define the relationship between decreases in ozone and the subsequent increases in skin cancer," he said. "The answer is quite clear -- if you multiply the fractional decrease in ozone protection by about three, you get the increase in skin cancer incidence. There are 1 million new skin cancer cases in the U.S. annually -- it's the most common form of cancer, and it's one that's increasing in spite of all the medical research devoted to it."

But it isn't only humans who have to worry about the effects of increased UV radiation.

Many crops, particularly staple crops grown for human consumption -- such as wheat, soybeans and corn -- could suffer damage to their DNA, Anderson said.

Ironically, Anderson said, the discovery that climate change might be driving ozone loss happened virtually by accident.

Though they had worked since the mid-1980s to investigate ozone depletion in the Arctic and Antarctic, by the early-2000s, Anderson's team had turned their attention to climate studies. In particular, they were working to understand how the convective clouds -- updrafts that cause storms to build high into the sky -- contribute to the creation of cirrus clouds.

"It was in the process of looking at that mechanism that we came to this unexpected observation -- that the convective clouds in these storm systems over the U.S. are reaching far deeper into the stratosphere that we ever expected," Anderson said.

While earlier tests performed in the Arctic had demonstrated that water vapor was a key component in creating the "free-radical" compounds that break down ozone, Anderson said the latest finding is much more troubling, because it suggests the process can happen at much higher temperatures than initially suspected.

"The bottom line is that if you increase the water vapor concentration, you actually increase the threshold temperature for executing this chemical conversion -- from the stable forms of chlorine to the free radical form," Anderson said. "If the amount of water vapor and the temperature over the U.S. satisfies the conditions for rapid conversion of inorganic chlorine to this free-radical form, we've got a real problem, because the chemistry is identical to what we previously demonstrated is taking place over the Arctic."

Also surprising, he added, was the realization that, to throw water vapor high into the atmosphere, storms needn't be unusually large.

"We have hundreds of measurements world-wide addressing the photochemical structure controlling ozone, but only a limited number of flights over the U.S. in summer," he said. "The flights were studying average storms over the middle-west, and of the 20 observations we made over the U.S., about half demonstrated significant penetration into the stratosphere," he said.


The next step in the research, Anderson said, is to conduct a series of tests to confirm whether the free-radical form of chlorine and bromine are present in the stratosphere at significantly elevated levels in the presence of convectively-injected water vapor.

"In my mind, this is not just a broad public health issue," Anderson said. "This is about actually being able to step out into the sunlight -- it's about your children and your children's health. Of course, we don't know how rapidly the frequency and intensity of these storms will increase, so we can't place a time scale on this problem, but the core issue here is quite straightforward and simple, because we understand this chemistry."

Story Source:

The above story is reprinted from materials provided by Harvard University, via EurekAlert!, a service of AAAS.

Journal Reference:
  1. James G. Anderson, David M. Wilmouth, Jessica B. Smith, and David S. Sayres. UV Dosage Levels in Summer: Increased Risk of Ozone Loss from Convectively Injected Water Vapor. Science, 26 July 2012 DOI: 10.1126/science.1222978

Global CO2

Emissions Continued to Increase in 2011, With Per Capita Emissions in China Reaching European Levels

http://www.sciencedaily.com/releases/2012/07/120719115130.htm

ScienceDaily (July 19, 2012) ­ Global emissions of carbon dioxide (CO2) -- the main cause of global warming -- increased by 3% last year, reaching an all-time high of 34 billion tonnes in 2011. In China, the world's most populous country, average emissions of CO2 increased by 9% to 7.2 tonnes per capita. China is now within the range of 6 to 19 tonnes per capita emissions of the major industrialised countries. In the European Union, CO2 emissions dropped by 3% to 7.5 tonnes per capita. The United States remains one of the largest emitters of CO2, with 17.3 tones per capita, despite a decline due to the recession in 2008-2009, high oil prices and an increased share of natural gas.

These are the main findings of the annual report 'Trends in global CO2 emissions', released July 19 by the European Commission's Joint Research Centre (JRC) and the Netherlands Environmental Assessment Agency (PBL).

Based on recent results from the Emissions Database for Global Atmospheric Research (EDGAR) and latest statistics on energy use and relevant activities such as gas flaring and cement production, the report shows that global CO2 emissions continued to grow in 2011, despite reductions in OECD countries. Weak economic conditions, a mild winter, and energy savings stimulated by high oil prices led to a decrease of 3% in CO2 emissions in the European Union and of 2% in both the United States and Japan. Emissions from OECD countries now account for only one third of global CO2 emissions -- the same share as that of China and India combined, where emissions increased by 9% and 6% respectively in 2011. Economic growth in China led to significant increases in fossil fuel consumption driven by construction and infrastructure expansion. The growth in cement and steel production caused China's domestic coal consumption to increase by 9.7%.

The 3% increase in global CO2 emissions in 2011 is above the past decade's average annual increase of 2.7%, with a decrease in 2008 and a surge of 5% in 2010. The top emitters contributing to the 34 billion tonnes of CO2 emitted globally in 2011 are: China (29%), the United States (16%), the European Union (11%), India (6%), the Russian Federation (5%) and Japan (4%).

Cumulative CO2 emissions call for action

An estimated cumulative global total of 420 billion tonnes of CO2 were emitted between 2000 and 2011 due to human activities, including deforestation. Scientific literature suggests that limiting the rise in average global temperature to 2°C above pre-industrial levels -- the target internationally adopted in UN climate negotiations -- is possible only if cumulative CO2 emissions in the period 2000-2050 do not exceed 1 000 to 1 500 billion tonnes. If the current global trend of increasing CO2 emissions continues, cumulative emissions will surpass this limit within the next two decades

Fortunately, this trend is being mitigated by the expansion of renewable energy supplies, especially solar and wind energy and biofuels. The global share of these so-called modern renewables, which exclude hydropower, is growing at an accelerated speed and quadrupled from 1992 to 2011. This potentially represents about 0.8 billion tonnes of CO2 emissions avoided as a result of using renewable energy supplies in 2011, which is close to Germany's total CO2 emissions in 2011.

"Trends in global CO2 emissions" report: http://edgar.jrc.ec.europa.eu/CO2REPORT2012.pdf

Story Source:
The above story is reprinted from materials provided by European Commission, Joint Research Centre (JRC)

Glacier Break Creates Ice Island Twice Size of Manhattan

http://www.sciencedaily.com/releases/2012/07/120717100027.htm

ScienceDaily (July 17, 2012) ­ An ice island twice the size of Manhattan has broken off from Greenland's Petermann Glacier, according to researchers at the University of Delaware and the Canadian Ice Service. The Petermann Glacier is one of the two largest glaciers left in Greenland connecting the great Greenland ice sheet with the ocean via a floating ice shelf.

Andreas Muenchow, associate professor of physical ocean science and engineering in UD's College of Earth, Ocean, and Environment, reports the calving on July 16, 2012, in his "Icy Seas" blog (http://icyseas.org/). Muenchow credits Trudy Wohleben of the Canadian Ice Service for first noticing the fracture.

The discovery was confirmed by reprocessing data taken by MODIS, the Moderate Resolution Imaging Spectroradiometer aboard NASA's Terra and Aqua satellites.

At 46 square miles (120 square km), this latest ice island is about half the size of the mega-calving that occurred from the same glacier two years ago. The 2010 chunk, also reported by Muenchow, was four times the size of Manhattan.

"While the size is not as spectacular as it was in 2010, the fact that it follows so closely to the 2010 event brings the glacier's terminus to a location where it has not been for at least 150 years," Muenchow says.

"The Greenland ice sheet as a whole is shrinking, melting and reducing in size as the result of globally changing air and ocean temperatures and associated changes in circulation patterns in both the ocean and atmosphere," he notes.

Muenchow points out that the air around northern Greenland and Ellesmere Island has warmed by about 0.11 +/- 0.025 degrees Celsius per year since 1987.

"Northwest Greenland and northeast Canada are warming more than five times faster than the rest of the world," Muenchow says, "but the observed warming is not proof that the diminishing ice shelf is caused by this, because air temperatures have little effect on this glacier; ocean temperatures do, and our ocean temperature time series are only five to eight years long -- too short to establish a robust warming signal."

The ocean and sea ice observing array that Muenchow and his research team installed in 2003 with U.S. National Science Foundation support in Nares Strait, the deep channel between Greenland and Canada, has recorded data from 2003 to 2009.

The Canadian Coast Guard Ship Henry Larsen is scheduled to travel to Nares Strait and Petermann Fjord later this summer to recover moorings placed by UD in 2009. These mooring data, if recovered, will provide scientists with ocean current, temperature, salinity and ice thickness data at better than hourly intervals from 2009 through 2012. The period includes the passage of the 2010 ice island directly over the instruments.

According to Muenchow, this newest ice island will follow the path of the 2010 ice island, providing a slow-moving floating taxi for polar bears, seals and other marine life until it enters Nares Strait, the deep channel between northern Greenland and Canada, where it likely will get broken up.

"This is definitely déjà vu," Muenchow says. "The first large pieces of the 2010 calving arrived last summer on the shores of Newfoundland, but there are still many large pieces scattered all along eastern Canada from Lancaster Sound in the high Arctic to Labrador to the south."

Prior to 2010, the last time such a sizable ice island was born in the region was 50 years ago. In 1962, the Ward Hunt Ice Shelf, on the northern coast of Ellesmere Island in Nunavut, Canada, calved a 230-square-mile island.

Story Source:
The above story is reprinted from materials provided by University of Delaware. The original article was written by Tracey Bryant.


Extreme Heat Raises Climate Change Questions, Concerns

http://www.sciencedaily.com/releases/2012/07/120705204935.htm
ScienceDaily (July 5, 2012) ­ The recent heat wave baking much of the country has prompted many people to ask: Is this due to climate change?

"This is always the million-dollar question, but unfortunately, there's no definitive way to answer it," says Steve Vavrus, a senior scientist in the Nelson Institute Center for Climatic Research at the University of Wisconsin-Madison. "We've experienced extreme heat, drought, floods, wildfires and windstorms throughout history, so in a sense this is nothing unusual. We need time to assess whether this year's set of extreme weather events falls outside of normal variations."

The list of unusual conditions over the past year is long. According to the National Oceanic and Atmospheric Administration (NOAA), last winter was the fourth-warmest on record in the United States; spring was the warmest since recordkeeping began in 1895; and April marked the end of the warmest 12-month period in U.S. history.

Still, Vavrus says scientists need more information to determine whether global warming is to blame. But he says heat waves like the current one will become more common on a warmer planet as we continue to add greenhouse gases such as carbon dioxide to the atmosphere, primarily through the burning of fossil fuels.

"I think it's a harbinger of what's to come under greenhouse warming," says Vavrus. "Virtually all climate models simulate more intense and frequent heat waves as the climate warms, and most of the world has experienced increases in extreme heat during the past several decades."

That's not good news for air quality or human health. Tracey Holloway, an associate professor of environmental studies, atmospheric and oceanic sciences, and civil and environmental engineering, says hotter temperatures lead to more ground-level ozone. Breathing ozone can damage lungs and worsen bronchitis, emphysema and asthma, and particulate air pollutants can affect a person's lungs and heart.

"Over the past few weeks, both ozone and particulate matter have increased across much of the country, with the Air Quality Index registering levels deemed 'unhealthy' or 'unhealthy for sensitive groups,'" says Holloway. "In the last week of June, moderate or unhealthy air covered a third to half of the continental U.S."

She says overall air quality typically degrades in hot conditions through a variety of physical and chemical processes.

"Often on the hottest days, we have very stagnant air, so emissions from cars and trucks, power plants and industry, along with natural emissions, have no place to go," she explains. "They hang around near the surface and react in the atmosphere to form ozone and some types of particles."

Holloway says heat-related events such as wildfires add harmful pollutants, and the increasing demand for air conditioning drives up power plant emissions.

In addition to causing respiratory issues, the excess heat poses direct health risks, according to Jonathan Patz, a professor of environmental studies and population health sciences and director of the UW-Madison Global Health Institute.

"Of all natural disasters in the U.S., heat waves have caused the most mortality," he says. "This week's heat wave began relatively early in the summer, and early-season heat waves can be particularly deadly, since we are less adapted to the heat, both physiologically and behaviorally."

Patz participated in a recent study of hospitalizations during heat waves in Milwaukee over a 16-year period.

"We found that risks to people with endocrine diseases such as diabetes, and renal disorders like kidney stones, increase during extreme heat waves," says Patz. "So do attempted suicides."

He says people in certain urban locations are more affected by the heat.

"Individuals who live on top-floor apartments, especially those without air conditioning, are at greater risk," he says. "Locations with more black asphalt roofs and roadways can be hotter than areas with more trees and green-space."

Patz says the health risks are compounded when extreme heat causes or combines with power outages, such as the extensive loss of electricity following intense wind storms that cut across the Midwest and mid-Atlantic last Friday.

"Such events are stark reminders of just how vulnerable we remain to extreme weather events," he says.

Whether these recent risks and impacts are the result of global climate change remains an unresolved question, according to Jack Williams, director of the Nelson Institute Center for Climatic Research. But he says there's no doubt that the global climate is changing.

"For the last 40 years of global warming, there is nothing comparable in the instrumental record since about 1880," Williams says. "To find comparable analogs for the amount of warming expected for this century under standard greenhouse gas emission scenarios, you have to go back to the climate changes accompanying the last deglaciation, about 20,000 years ago."
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The above story is reprinted from materials provided by University of Wisconsin-Madison. The original article was written by Steve Pomplun.

Arctic Warming Linked to Combination of Reduced Sea Ice and Global Atmospheric Warming
http://www.sciencedaily.com/releases/2012/07/120706164203.htm
ScienceDaily (July 6, 2012) ­ The combination of melting sea ice and global atmospheric warming are contributing to the high rate of warming in the Arctic, where temperatures are increasing up to four times faster than the global average, a new University of Melbourne study has shown.

Professor Ian Simmonds from the University of Melbourne's School of Earth Sciences co-authored the study and said the new information showed this combined effect at both ground and atmospheric level played a key role in increasing the rate of warming in the Arctic.

"Loss of sea ice contributes to ground level warming while global warming intensifies atmospheric circulation and contributes to increased temperatures higher in the Arctic atmosphere," Professor Simmonds said.

Lead author, Dr James Screen of the School of Earth Sciences at the University of Melbourne, said the sea ice acted like a shiny lid on the Arctic Ocean.

"When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it," he said.

Professor Simmonds said as temperatures increase across the globe, so does the intensity of atmospheric circulation.

"This circulation transports energy to the Arctic region, increasing temperatures further up in the atmosphere," he said.

"Water vapour is a very strong greenhouse gas. As the atmosphere warms it can hold more moisture, which acts as a positive feedback signal, increasing the greenhouse effect. However, in the cold Arctic where there is less moisture in the air, this positive feedback is much weaker hence the 'direct' greenhouse effect is smaller in the Arctic than elsewhere.

"Even though the Arctic region has a relatively small greenhouse effect, the effect of the melted ice combined with greater transports of heat from the south are more than enough to make up for this modest 'local' greenhouse warming."

The study was published in Geophysical Research Letters and featured in Nature.
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The above story is reprinted from materials provided by University of Melbourne.

Heating Up

The recent heat wave that has fried much of the country, ruined crops and led to heat-related deaths has again raised the question of whether this and other extreme weather events can be attributed to human-induced climate change. The answer, increasingly, is a qualified yes.

Mainstream scientists have always been cautious about drawing a causal link between global warming and any specific weather event; the world has experienced calamitous heat waves, droughts, wildfires and floods throughout its history. But they also agree that without sustained efforts to reduce greenhouse gases, dangerous heat waves are very likely to become more common, as will prolonged droughts and coastal flooding.

Many politicians and a vocal minority of scientists dispute such predictions as alarmist. What they cannot dispute are the numbers. According to the National Oceanic and Atmospheric Administration, the 11 years from 2001-11 rank among the 13 warmest globally since record-keeping began 132 years ago. The average temperature in the contiguous United States for the first six months of this year, the National Climatic Data Center reported on Monday, were the hottest recorded since 1895.

The Intergovernmental Panel on Climate Change, the United Nations body that examines climate change with help from thousands of scientists around the world, says that more frequent and potentially more damaging extreme weather events lie ahead. In a report last November assessing weather extremes, the panel said that “it is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur in the 21st century on the global scale.” If greenhouse gases continue unabated, it said, heat waves that now occur once every 20 years will be occurring every two years by the end of the century.

The climate panel is a judicious group, and it warned that against premature judgments. Following Hurricane Katrina, for instance, some climate experts suggested that rising global temperatures would produce more intense hurricanes. The panel said it did not have the evidence to establish such a link.

On the whole, however, its findings support the evidence presented by the basic science: warmer air makes heat waves and droughts more intense; warmer air also holds more water vapor, which increases the risk of destructive floods.

As Michael Oppenheimer, a Princeton University climate scientist and the lead author of the report, said: “A hotter, moister atmosphere is an atmosphere primed to trigger disasters.”

History is full of sad stories of humanity’s inability to see the writing on the wall ­ overplowing that helped produce the Dust Bowl, overfishing that has depopulated the oceans. The heat wave is merely the latest of many weather-related messages that should be easy to read.

Greater Los Angeles to Heat Up an Average 4 to 5 Degrees by Mid-Century
http://www.sciencedaily.com/releases/2012/06/120621195908.htm

ScienceDaily (June 21, 2012) ­ A ground breaking new study led by UCLA climate expert Alex Hall shows that climate change will cause temperatures in the Los Angeles region to rise by an average of 4 to 5 degrees Fahrenheit by the middle of this century, tripling the number of extremely hot days in the downtown area and quadrupling the number in the valleys and at high elevations.

Released June 22, "Mid-Century Warming in the Los Angeles Region" is the first study to provide specific climate-change predictions for the greater Los Angeles area, with unique predictions down to the neighborhood level. The report, the most sophisticated regional climate study ever developed, was produced by UCLA with funding and support from the city of Los Angeles, in partnership with the Los Angeles Regional Collaborative for Climate Action and Sustainability (LARC).

"The changes our region will face are significant, and we will have to adapt," said Hall, an associate professor in UCLA's Department of Atmospheric and Oceanic Sciences who is also a lead author on the Intergovernmental Panel on Climate Change reports, which, among other things, assess global climate-change simulations for the United Nations.

"Every season of the year in every part of the county will be warmer," Hall said. "This study lays a foundation for the region to confront climate change. Now that we have real numbers, we can talk about adaptation."

The LARC's unprecedented coalition of cities, universities, businesses, non-profits and other agencies made the study possible. Mayor Antonio Villaraigosa and the city of Los Angeles led the way, obtaining a $613,774 grant from the U.S. Department of Energy to study and share climate research and committing $484,166 to commission UCLA's climate-change study. Though scientists knew to expect warming, this is the first time policymakers in the Los Angeles area have precise information on which to base their plans.

"UCLA's model shows projected climate changes down to the neighborhood level, allowing us to apply the rigor of science to long-term planning for our city and our entire region," Villaraigosa said. "With good data driving good policies, we can craft innovative solutions that will preserve our environment and enhance the quality of life for the next generation of Angelenos."

Facts and figures from the study

The study looked at the years 2041-60 to predict the average temperature change by mid-century. The data covers all of Los Angeles County and 30 to 60 miles beyond, including all of Orange County and parts of Ventura, San Bernardino and Riverside counties, and reaching as far as Palm Springs, Bakersfield and Santa Barbara. The study overlaid this entire area with a grid of squares 1.2 miles across and provided unique temperature predictions for each square. This is in contrast to global climate models, which normally use grids 60 to 120 miles across -- big enough to include areas as different as Long Beach and Lancaster.

According to the study, coastal areas like Santa Monica and Long Beach are likely to warm an average of 3 to 4 degrees. Dense urban areas like downtown Los Angeles and the San Fernando and San Gabriel valleys will warm an average of 4 degrees, and mountain and desert regions like Palm Springs and Lancaster will warm 4 to 5 degrees.

Some of the smallest changes predicted, yet still nearing a 4-degree increase, are in Oxnard (3.68 degrees), Venice (3.70), Santa Barbara (3.73), Santa Monica (3.74), San Pedro (3.78), Torrance (3.80), Long Beach (3.82) and Santa Ana (3.85). Among the highest predicted increases are Wrightwood (5.37), Big Bear Lake (5.23), Palm Springs (5.15), Palmdale (4.92), Lancaster (4.87), Bakersfield (4.48) and Santa Clarita (4.44). Table 2 in the study calls out 27 distinct locations, such as downtown Los Angeles (3.92), San Fernando (4.19), Woodland Hills (4.26), Eagle Rock (3.98), Pasadena (4.05), Pomona (4.09), Glendale (3.99) and Riverside (4.23).

These figures are only annual averages, and the day-to-day increase in temperatures will vary, said Hall, who is a member of UCLA's Institute of the Environment and Sustainability (IoES) and director of the institute's Center for Climate Change Solutions. Southern Californians should expect slightly warmer winters and springs but much warmer summers and falls, with more frequent heat waves. Temperatures now seen only on the seven hottest days of the year in each region will occur two to six times as often. The number of days when the temperature will climb above 95 degrees will increase two to four times, depending on the location. Those days will roughly double on the coast, triple in downtown Los Angeles and Pasadena, and quadruple in Woodland Hills. In Palm Springs, the number of extremely hot days will increase from an annual average of 75 to roughly 120.

"Places like Lancaster and Palm Springs are already pretty hot areas, and when you tack on warming of 5 to 6 degrees, that's a pretty noticeable difference," Hall said. "If humans are noticing it, so are plants, animals and ecosystems. These places will be qualitatively different than they are now."

The most sophisticated regional climate study ever developed

The type of climate modeling used in the study is done almost exclusively at the national or international level, said Paul Bunje, the managing director of the LARC, which is based at UCLA's Institute of the Environment and Sustainability. Other cities and states have localized global climate models -- but usually by localizing only one model. Hall's team needed months of computer time to downscale 22 global climate models, each with slightly different assumptions about how to predict climate change or factors like future greenhouse gas emissions.

Hall's team included UCLA postdoctoral students Fengpeng Sun and Daniel Walton and graduate student Mark Nakamura. Once they recalculated the almost two dozen global models at the local level, the team analyzed the results and integrated them into an ensemble projection to create the forecast for the entire region.

"This is the best, most sophisticated climate science ever done for a city," said Bunje, who is also the executive director of UCLA's IoES Center for Climate Change Solutions.

"L.A. is one of the first cities to get its act together, from the scientists all the way up to the mayor," Bunje said. "Nobody knew precisely how to adapt to climate change because no one had the data -- until now. These are shocking numbers, and we will have to adapt."

Cutting emissions will reduce but not eliminate warming

Cutting greenhouse gas emissions could reduce the impact on Los Angeles, Hall said. However, even if the world has unanticipated -- and perhaps unrealistic -- success in drastically reducing greenhouse gas emissions, the greater Los Angeles area will still warm to about 70 percent of the currently predicted levels, the study found.

"We looked not only at a business-as-usual scenario where greenhouse gas emissions continue but also at a scenario where emissions are curtailed," Hall said. "Even if we drastically cut pollution worldwide, there will still be quite a bit of warming in Los Angeles. I was a little taken aback by how much warming remains, no matter how aggressively we cut back. It was sobering."

"Mid-Century Warming in the Los Angeles Region" is the first of five planned studies Hall will conduct for the city and the LARC about how climate change will affect the Southland. Hall's team plans to develop similarly comprehensive models for local rainfall, Santa Ana wind patterns, coastal fog (including June gloom), and soil moisture, run-off and evaporation. Preliminary results already show that Santa Ana winds and June gloom will react to climate change, Hall said.

Global warming is local warming

"I think for many people, climate change still feels like a nebulous, abstract, potential future change, and this makes it more real," Hall said. "It's eye-opening to see how much it will warm where you live. This data lays a foundation for really confronting this issue, and I'm very optimistic that we can confront and adapt to a changing climate."

Report: http://c-change.la/pdf/LARC-web.pdf
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The above story is reprinted from materials provided by University of California - Los Angeles. The original article was written by Alison Hewitt.

Drought Monitor Shows Record-Breaking Expanse of Drought Across United States

http://www.sciencedaily.com/releases/2012/07/120705194136.htm

ScienceDaily (July 5, 2012) ­ More of the United States is in moderate drought or worse than at any other time in the 12-year history of the U.S. Drought Monitor, officials from the National Drought Mitigation Center at the University of Nebraska-Lincoln said July 5.

Analysis of the latest drought monitor data revealed that 46.84 percent of the nation's land area is in various stages of drought, up from 42.8 percent a week ago. Previous records were 45.87 percent in drought on Aug. 26, 2003, and 45.64 percent on Sept. 10, 2002.

Looking only at the 48 contiguous states, 55.96 percent of the country's land area is in moderate drought or worse -- also the highest percentage on record in that regard, officials said. The previous highs had been 54.79 percent on Aug. 26, 2003, and 54.63 percent on Sept. 10, 2002.

"The recent heat and dryness is catching up with us on a national scale," said Michael J. Hayes, director of the National Drought Mitigation Center. "Now, we have a larger section of the country in these lesser categories of drought than we've previously experienced in the history of the Drought Monitor."

The monitor uses a ranking system that begins at D0 (abnormal dryness) and moves through D1 (moderate drought), D2 (severe drought), D3 (extreme drought) and D4 (exceptional drought).

Moderate drought's telltale signs are some damage to crops and pastures, with streams, reservoirs or wells getting low. At the other end of the scale, exceptional drought includes widespread crop and pasture losses, as well as shortages of water in reservoirs, streams and wells, creating water emergencies. So far, just 8.64 percent of the country is in either extreme or exceptional drought.

"During 2002 and 2003, there were several very significant droughts taking place that had a much greater areal coverage of the more severe and extreme drought categories," Hayes said. "Right now we are seeing pockets of more severe drought, but it is spread out over different parts of the country.

"It's early in the season, though. The potential development is something we will be watching."

The U.S. Drought Monitor is a joint endeavor by the National Drought Mitigation Center at UNL, the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and drought observers across the country.

To examine the monitor's current and archived national, regional and state-by-state drought maps and conditions, go to http://droughtmonitor.unl.edu .

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The above story is reprinted from materials provided by University of Nebraska-Lincoln.

U.S. Experienced Second Warmest May, Warmest Spring On Record, NOAA Reports

http://www.sciencedaily.com/releases/2012/06/120607185751.htm

ScienceDaily (June 7, 2012) ­ According to NOAA scientists, the average temperature for the contiguous U.S. during May was 64.3°F, 3.3°F above the long-term average, making it the second warmest May on record. The month's high temperatures also contributed to the warmest spring, warmest year-to-date, and warmest 12-month period the nation has experienced since record keeping began in 1895.

The spring season's (March-May) nationally averaged temperature was 57.1°F, 5.2°F above the 1901-2000 long-term average, surpassing the previous warmest spring (1910) by 2.0°F.

Precipitation totals across the country were mixed during May, with the nation as a whole being drier-than-average. The nationally averaged precipitation total of 2.51 inches was 0.36 inch below average. The coastal Southeast received some drought relief when Tropical Storm Beryl brought heavy rains to the region late in the month.

This monthly analysis from NOAA's National Climatic Data Center is part of the suite of climate services NOAA provides government, business and community leaders so they can make informed decisions.

U.S. climate highlights -- May
U.S. climate highlights -- spring (March-May)
Year-to-date (January-May)
12-month period (June 2011-May 2012)
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The above story is reprinted from materials provided by National Oceanic and Atmospheric Administration.

Arctic Ice Melt Is Setting Stage for Severe Winters

http://www.sciencedaily.com/releases/2012/06/120606132420.htm

ScienceDaily (June 6, 2012) ­ The dramatic melt-off of Arctic sea ice due to climate change is hitting closer to home than millions of Americans might think.

That's because melting Arctic sea ice can trigger a domino effect leading to increased odds of severe winter weather outbreaks in the Northern Hemisphere's middle latitudes -- think the "Snowmageddon" storm that hamstrung Washington, D.C., during February 2010.

Cornell's Charles H. Greene, professor of earth and atmospheric sciences, and Bruce C. Monger, senior research associate in the same department, detail this phenomenon in a paper published in the June issue of the journal Oceanography.

"Everyone thinks of Arctic climate change as this remote phenomenon that has little effect on our everyday lives," Greene said. "But what goes on in the Arctic remotely forces our weather patterns here."

A warmer Earth increases the melting of sea ice during summer, exposing darker ocean water to incoming sunlight. This causes increased absorption of solar radiation and excess summertime heating of the ocean -- further accelerating the ice melt. The excess heat is released to the atmosphere, especially during the autumn, decreasing the temperature and atmospheric pressure gradients between the Arctic and middle latitudes.

A diminished latitudinal pressure gradient is associated with a weakening of the winds associated with the polar vortex and jet stream. Since the polar vortex normally retains the cold Arctic air masses up above the Arctic Circle, its weakening allows the cold air to invade lower latitudes.

The recent observations present a new twist to the Arctic Oscillation -- a natural pattern of climate variability in the Northern Hemisphere. Before humans began warming the planet, the Arctic's climate system naturally oscillated between conditions favorable and those unfavorable for invasions of cold Arctic air.

"What's happening now is that we are changing the climate system, especially in the Arctic, and that's increasing the odds for the negative AO conditions that favor cold air invasions and severe winter weather outbreaks," Greene said. "It's something to think about given our recent history."

This past winter, an extended cold snap descended on central and Eastern Europe in mid-January, with temperatures approaching minus 22 degrees Fahrenheit and snowdrifts reaching rooftops. And there were the record snowstorms fresh in the memories of residents from several eastern U.S. cities, such as Washington, New York and Philadelphia, as well as many other parts of the Eastern Seaboard during the previous two years.

Greene and Monger did note that their paper is being published just after one of the warmest winters in the eastern U.S. on record.

"It's a great demonstration of the complexities of our climate system and how they influence our regional weather patterns," Greene said.

In any particular region, many factors can have an influence, including the El Nino/La Nina cycle. This winter, La Nina in the Pacific shifted undulations in the jet stream so that while many parts of the Northern Hemisphere were hit by the severe winter weather patterns expected during a bout of negative AO conditions, much of the eastern United States basked in the warm tropical air that swung north with the jet stream.

"It turns out that while the eastern U.S. missed out on the cold and snow this winter, and experienced record-breaking warmth during March, many other parts of the Northern Hemisphere were not so fortunate," Greene said.

Europe and Alaska experienced record-breaking winter storms, and the global average temperature during March 2012 was cooler than any other March since 1999.

"A lot of times people say, 'Wait a second, which is it going to be -- more snow or more warming?' Well, it depends on a lot of factors, and I guess this was a really good winter demonstrating that," Greene said. "What we can expect, however, is the Arctic wild card stacking the deck in favor of more severe winter outbreaks in the future."


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The above story is reprinted from materials provided by Cornell University. The original article was written by Anne Ju.

Adirondack Lakes in North Eastern US Lose Ice Cover as Climate Warms: Most Pristine Lake Marks Biggest Change

http://www.sciencedaily.com/releases/2012/05/120507164334.htm

ScienceDaily (May 7, 2012) ­ Lakes in the undeveloped High Peaks area of the Adirondack Park are covered with ice for significantly shorter periods than they were 32 years ago, providing evidence that climate change is occurring rapidly and that not even the most pristine wilderness areas are immune.

Since 1975, five high-elevation lakes in the Adirondacks have had rapid decreases in the duration of ice cover and are now frozen for 7 to 21 fewer days on average, according to a study published April 30 in the journal Climatic Change by a team of researchers at the SUNY College of Environmental Science and Forestry (ESF).

"It shows us in a detailed way that the climate is warming in the Adirondacks, that it's warming in a way we might not expect," said Dr. Colin Beier, a research ecologist who is the paper's lead author.

Beier said analysis of local climate and lake ice records at ESF's Adirondack Ecological Center (AEC) in Newcomb shows the biggest change in ice cover has occurred in the fall and early winter, with ice forming on the various lakes about two days to two weeks later over the study period. The "ice-out" dates, marking the day the ice was considered melted, changed much less, probably because of the insulating value of snow cover. Three of the lakes recorded no consistent changes in the ice-out date; the biggest change observed was five days. This marks a difference from many previous studies of lake ice in the Northeast, which found more significant changes in ice cover were occurring in the spring.

Beier said the most pristine lake in the study group proved to be the most sensitive to recent warming.

All the lakes studied are within ESF's 15,000-acre Huntington Wildlife Forest, near the geographic center of the park: Arbutus, Catlin, Deer, Rich and Wolf. The most severely affected by recent warming was Wolf Lake, classified as a "Heritage Lake" because of its pristine condition. It contains no non-native species and it has not been negatively affected by acid rain; analysis of its sediments indicates Wolf Lake is in much the same condition it was before Christopher Columbus set sail. The study showed it has lost a full three weeks of ice cover since 1975. The equivalent time for the other four lakes ranged from 7 to 17 days.

"There's no evidence of human impact on the lake. It's a little tiny pocket of untouched ecology," Beier said. "But of the lakes we looked at, it shows the most change, both in the timing of the ice forming and melting, and in its shrinking duration. Conservation efforts are probably helping to protect it but conservation is not a panacea.

"Climate change is a game changer in conservation," he said. "There are places where you've done everything you can to protect these ecosystems and you think they're safe. They're not."

The difference in lake ice duration could affect recreational and tourism activities such as snowmobiling and ice fishing as well as impact water levels in the Hudson River, which flows from Adirondack headwaters. It could also have broad environmental effects on the life cycles of plants and animals. One of the most significant species that could be affected in the Adirondacks is the endangered native brook trout, a cold-water species that attracts recreational fishermen. Brook trout are stressed by warmer water and could face increased competition by other fish species adapted to warm water conditions.

Beier said the study shows the value of long-term data collection and proves the need for more research. "Our knowledge of climate change outpaces our knowledge of how it affects our local ecosystems," he said. "The reality is changes are happening that we have to pay attention to if we are going to adapt to them."

Beier's co-authors were ESF faculty members Dr. John Stella and Dr. Martin Dovciak and Stacy McNulty, a researcher at the AEC. Data for the study were collected as part of the Adirondack Long-Term Monitoring Program at the AEC.


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The above story is reprinted from materials provided by SUNY College of Environmental Science and Forestry, via Newswise.

Journal Reference:
  1. Colin M. Beier, John C. Stella, Martin Dov iak, Stacy A. McNulty. Local climatic drivers of changes in phenology at a boreal-temperate ecotone in eastern North America. Climatic Change, 2012; DOI: 10.1007/s10584-012-0455-z

U. S. Temperatures Hit Record Highs in March



http://www.sciencedaily.com/releases/2012/04/120403153533.htm

ScienceDaily (Apr. 3, 2012) ­ Compared to seasonal norms, March 2012 was the warmest month on record in the 48 contiguous U.S. states. Temperatures over the U.S. averaged 2.82 C (almost 5.1 degrees Fahrenheit) warmer than normal in March.

The previous U.S. record warm anomaly in the 33-year satellite temperature record was in November 1999, when temperatures over the U.S. averaged 2.22 C (about 4° F) warmer than the seasonal norm for November. The next warmest March was in 2007, when temperatures over the U.S. were 2.0 C (about 3.2° F) warmer than normal.

While the long-term climate trend over the U.S. has seen warming at the rate of about 0.21 C (almost 0.38° F) per decade during the past one third of a century, March's temperature anomaly is just that: an anomaly, said Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. "We see hot and cold spots over the globe every month, and this was just our turn. A one-time anomaly like this is related to weather rather than climate. Weather systems aligned in March in a way that changed normal circulation patterns and brought more warm air than usual to the continental U.S."

In fact, the warmest spot on the globe in March (compared to seasonal norms) was northeastern Iowa, where temperatures for the month averaged 6.20 C (about 11.2° F) warmer than normal.

By comparison, the winter (DJF) of 2011-2012 averaged 0.94 C (about 1.7° F) warmer than seasonal norms for the continental U.S.

In recent years March has not typically seen temperature extremes over the U.S. The March 2011 temperature for the "lower 48" was at the seasonal norm.

The coolest spot on Earth in March 2012 was northwestern Alaska, where temperatures averaged 3.89 C (7.0° F) colder than normal.


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The above story is reprinted from materials provided by University of Alabama Huntsville, via Newswise.

New Report On the State of Polar Regions

http://www.sciencedaily.com/releases/2012/04/120403193733.htm

ScienceDaily (Apr. 3, 2012) ­ The U.S. National Research Council has just released a synthesis of reports from thousands of scientists in 60 countries who took part in the International Polar Year (IPY) 2007-08, the first in over 50 years to offer a benchmark for environmental conditions and new discoveries in the polar regions.

University of Massachusetts Amherst geosciences researcher and expert in the paleoclimate of the Arctic, Julie Brigham-Grette, co-chaired the NRC report, "Lessons and Legacies of the IPY 2007-08" with leading Antarctic climate scientist Robert Bindschadler of NASA.

Among the major findings is that global warming is changing the face of Antarctica and the Arctic faster than expected. For example, in 2007 scientists documented a 27 percent loss of sea ice in a single year, Brigham-Grette says. Also, ice sheets around the poles are now showing evidence of serious retreat, expected to continue and perhaps accelerate over coming centuries as warm ocean currents melt the ice front faster than anyone had grasped before. Sea level rise from melting polar ice sheets is today slowly affecting every shoreline on the planet.

"As a result of this work, we have a new benchmark. Seven of 12 Antarctic Peninsula ice shelves are either gone or now in severe decline," she adds. "This type of information makes the report all the more important because the changes we expect to see in the next few decades are going to be incredible."

As co-authors, she and Bindschadler testified last week before representatives of the National Science Foundation, its Office of Polar Programs, NASA, NOAA, the U.S. Geological Survey, Office of Naval Research, the State Department and the U.S. Arctic Research Commission. Additional briefings could be scheduled if there are questions or responses to the NRC from Congress, Brigham-Grette says.

Worldwide, scores of oceanographers, meteorologists, geologists, climate scientists, ecologists and other researchers contributed to the report. For example, biologists document diatoms, microscopic phytoplankton at the base of the food chain, in North Atlantic waters where they hadn't been in 800,000 years, the last time the Arctic provided a cold barrier to migration, Brigham-Grette says. Fish specialists see commercial and other species migrating ever northward to suitable habitats. "The fishermen are following," she says. "It's a whole new ballgame for the U.S. Coast Guard and those trying to regulate harvests."

The UMass Amherst geoscientist's own research using ancient sediment cores from Northeast Russia's Lake El'gygytgyn offers a new look at how Antarctic and Arctic warming over the last few million years occurred in sync when forced by the Earth system and feedbacks. "We're beginning to see that when the west Antarctic ice sheet collapses, the Arctic warms up. This is a new benchmark linking warming events in these two places for the first time."

In the Antarctic, new imaging techniques deployed during the recent IPY allowed scientists for the first time to visualize a new range, the Gamburtsev Mountains, with peaks as big as the Alps under the east Antarctic ice sheet. They may have been the ice sheet's nucleus millions of years ago. Others found hundreds of freshwater lakes under Antarctic ice, with more being discovered every day.

Brigham-Grette says, "I think if you look at everything we've learned, we see the polar regions are much more vulnerable to global warming than we thought. Global biological and oceanographic systems are responding faster than we ever expected. Earth has gone through this before, and some past warm cycles have been extreme, but we as humans have never seen anything like it in our 10,000 years on the planet. It's extraordinary."

As they release the NRC report to policymakers this week, Brigham-Grette says the authors understand that leaders must try to balance the country's energy needs at the same time they address global climate change by decreasing fossil fuel use.

Two social advances to emerge from the recent IPY are a remarkable increase in the number of women and minorities in leadership roles in science compared to 50 years ago along with the "massive" educational effort and increased interest in and public awareness of issues facing polar regions, she adds.

Among scientists, the IPY led to many new international and multi-disciplinary collaborations that promise to continue, says Brigham-Grette, plus a new international network of young polar scientists. "With the expense of travel and research today, no one country can do it alone, so there's more sharing of resources and data. It's a very much richer environment for study today."


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The above story is reprinted from materials provided by University of Massachusetts Amherst, via Newswise.

Amount of Coldest Antarctic Water Near Ocean Floor Decreasing for Decades
http://www.sciencedaily.com/releases/2012/04/120403153850.htm

ScienceDaily (Apr. 3, 2012) — Scientists have found a large reduction in the amount of the coldest deep ocean water, called Antarctic Bottom Water, all around the Southern Ocean using data collected from 1980 to 2011. These findings, in a study now online, will likely stimulate new research on the causes of this change.

Two oceanographers from NOAA and the University of Washington find that Antarctic Bottom Water has been disappearing at an average rate of about eight million metric tons per second over the past few decades, equivalent to about fifty times the average flow of the Mississippi River or about a quarter of the flow of the Gulf Stream in the Florida Straits.

"Because of its high density, Antarctic Bottom Water fills most of the deep ocean basins around the world, but we found that the amount of this water has been decreasing at a surprisingly fast rate over the last few decades," said lead author Sarah Purkey, graduate student at the School of Oceanography at the University of Washington in Seattle, Wash. "In every oceanographic survey repeated around the Southern Ocean since about the 1980s, Antarctic Bottom Water has been shrinking at a similar mean rate, giving us confidence that this surprisingly large contraction is robust."

Antarctic Bottom Water is formed in a few distinct locations around Antarctica, where seawater is cooled by the overlying air and made saltier by ice formation. The dense water then sinks to the sea floor and spreads northward, filling most of the deep ocean around the world as it slowly mixes with warmer waters above it.

The world's deep ocean currents play a critical role in transporting heat and carbon around the planet, thus regulating our climate.

While previous studies have shown that the bottom water has been warming and freshening over the past few decades, these new results suggest that significantly less of this bottom water has been formed during that time than in previous decades.

"We are not sure if the rate of bottom water reduction we have found is part of a long-term trend or a cycle," said co-author Gregory C. Johnson, Ph.D., an oceanographer at NOAA's Pacific Marine Environmental Laboratory in Seattle. "We need to continue to measure the full depth of the oceans, including these deep ocean waters, to assess the role and significance that these reported changes and others like them play in the Earth's climate."

Changes in the temperature, salinity, dissolved oxygen, and dissolved carbon dioxide of this prominent water mass have important ramifications for Earth's climate, including contributions to sea level rise and the rate of Earth's heat uptake.

"People often focus on fluctuations of currents in the North Atlantic Ocean as an indicator of climate change, but the Southern Ocean has undergone some very large changes over the past few decades and also plays a large role in shaping our climate," said Johnson.

The data used in this study are highly accurate temperature data repeated at roughly 10-year intervals by an international program of repeated ship-based oceanographic surveys. Within the U.S., the collection of these data has been a collaborative effort of governmental laboratory and university scientists, funded primarily by NOAA and the National Science Foundation. However, much of the data used in this study were measured by international colleagues.
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Story Source:

The above story is reprinted from materials provided by National Oceanic and Atmospheric Administration.
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Journal Reference:

1.Sarah G. Purkey, Gregory C. Johnson. Global contraction of Antarctic Bottom Water between the 1980s and 2000s*. Journal of Climate, 2012; : 120315135854004 DOI: 10.1175/JCLI-D-11-00612.1
Ocean Acidification Rate May Be Unprecedented, Study Says


 http://www.sciencedaily.com/releases/2012/03/120301143735.htm

ScienceDaily (Mar. 1, 2012) ­ The world's oceans may be turning acidic faster today from human carbon emissions than they did during four major extinctions in the last 300 million years, when natural pulses of carbon sent global temperatures soaring, says a new study in Science. The study is the first of its kind to survey the geologic record for evidence of ocean acidification over this vast time period.
"What we're doing today really stands out," said lead author Bärbel Hönisch, a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory. "We know that life during past ocean acidification events was not wiped out -- new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about -- coral reefs, oysters, salmon."
The oceans act like a sponge to draw down excess carbon dioxide from the air; the gas reacts with seawater to form carbonic acid, which over time is neutralized by fossil carbonate shells on the seafloor. But if CO2 goes into the oceans too quickly, it can deplete the carbonate ions that corals, mollusks and some plankton need for reef and shell-building.
That is what is happening now. In a review of hundreds of paleoceanographic studies, a team of researchers from five countries found evidence for only one period in the last 300 million years when the oceans changed even remotely as fast as today: the Paleocene-Eocene Thermal Maximum, or PETM, some 56 million years ago. In the early 1990s, scientists extracting sediments from the seafloor off Antarctica found a layer of mud from this period wedged between thick deposits of white plankton fossils. In a span of about 5,000 years, they estimated, a mysterious surge of carbon doubled atmospheric concentrations, pushed average global temperatures up by about6 degrees C, and dramatically changed the ecological landscape.
The result: carbonate plankton shells littering the seafloor dissolved, leaving the brown layer of mud. As many as half of all species of benthic foraminifers, a group of single-celled organisms that live at the ocean bottom, went extinct, suggesting that organisms higher in the food chain may have also disappeared, said study co-author Ellen Thomas, a paleoceanographer at Yale University who was on that pivotal Antarctic cruise. "It's really unusual that you lose more than 5 to 10 percent of species over less than 20,000 years," she said. "It's usually on the order of a few percent over a million years." During this time, scientists estimate, ocean pH -- a measure of acidity--may have fallen as much as 0.45 units. (As pH falls, acidity rises.)
In the last hundred years, atmospheric CO2 has risen about 30 percent, to 393 parts per million, and ocean pH has fallen by 0.1 unit, to 8.1--an acidification rate at least 10 times faster than 56 million years ago, says Hönisch. The Intergovernmental Panel on Climate Change predicts that pH may fall another 0.3 units by the end of the century,to 7.8, raising the possibility that we may soon see ocean changes similar to those observed during the PETM.
More catastrophic events have shaken earth before, but perhaps not as quickly. The study finds two other times of potential ocean acidification: the extinctions triggered by massive volcanism at the end of the Permian and Triassic eras, about 252 million and 201 million years ago respectively. But the authors caution that the timing and chemical changes of these events is less certain. Because most ocean sediments older than 180 million years have been recycled back into the deep earth, scientists have fewer records to work with.
During the end of the Permian, about 252 million years ago, massive volcanic eruptions in present-day Russia led to a rise in atmospheric carbon, and the extinction of 96 percent of marine life. Scientists have found evidence for ocean dead zones and the survival of organisms able to withstand carbonate-poor seawater and high blood-carbon levels, but so far they have been unable to reconstruct changes in ocean pH or carbonate.
At the end of the Triassic, about 201 million years ago, a second burst of mass volcanism doubled atmospheric carbon. Coral reefs collapsed and many sea creatures vanished. Noting that tropical species fared the worst, some scientists question if global warming rather than ocean acidification was the main killer at this time.
The effects of ocean acidification today are overshadowed for now by other problems, ranging from sewage pollution and hotter summer temperatures that threaten corals with disease and bleaching. However, scientists trying to isolate the effects of acidic water in the lab have shown that lower pH levels can harm a range of marine life, from reef and shell-building organisms to the tiny snails favored by salmon. In a recent study, scientists from Stony Brook University found that the larvae of bay scallops and hard clams grow best at pre-industrial pH levels, while their shells corrode at the levels projected for 2100. Off the U.S. Pacific Northwest, the death of oyster larvae has recently been linked to the upwelling of acidic water there.
In parts of the ocean acidified by underwater volcanoes venting carbon dioxide, scientists have seen alarming signs of what the oceans could be like by 2100. In a 2011 study of coral reefs off Papua New Guinea, scientists writing in the journal Nature Climate Change found that when pH dropped to 7.8, reef diversity declined by as much as 40 percent. Other studies have found that clownfish larvae raised in the lab lose their ability to sniff out predators and find their way home when pH drops below 7.8.
"It's not a problem that can be quickly reversed," said Christopher Langdon, a biological oceanographer at the University of Miami who co-authored the study on Papua New Guinea reefs. "Once a species goes extinct it's gone forever. We're playing a very dangerous game."
It may take decades before ocean acidification's effect on marine life shows itself. Until then, the past is a good way to foresee the future, says Richard Feely, an oceanographer at the National Oceanic and Atmospheric Administration who was not involved in the study. "These studies give you a sense of the timing involved in past ocean acidification events -- they did not happen quickly," he said. "The decisions we make over the next few decades could have significant implications on a geologic timescale."

The study was funded by the U.S. National Science Foundation.


Story Source:
The above story is reprinted from materials provided by The Earth Institute at Columbia University.

Journal Reference:
  1. Bärbel Hönisch, Andy Ridgwell, Daniela N. Schmidt, Ellen Thomas, Samantha J. Gibbs, Appy Sluijs, Richard Zeebe, Lee Kump, Rowan C. Martindale, Sarah E. Greene, Wolfgang Kiessling, Justin Ries, James C. Zachos, Dana L. Royer, Stephen Barker, Thomas M. Marchitto Jr., Ryan Moyer, Carles Pelejero, Patrizia Ziveri, Gavin L. Foster, and Branwen Williams. The Geological Record of Ocean Acidification. Science, March 2, 2012 DOI: 10.1126/science.1208277

ScienceDaily (Jan. 19, 2012) ­ The global average surface temperature in 2011 was the ninth warmest since 1880, according to NASA scientists. The finding continues a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since the year 2000.  NASA's Goddard Institute for Space Studies (GISS) in New York, which monitors global surface temperatures on an ongoing basis, released an updated analysis that shows temperatures around the globe in 2011 compared to the average global temperature from the mid-20th century. The comparison shows how Earth continues to experience warmer temperatures than several decades ago. The average temperature around the globe in 2011 was 0.92 degrees F (0.51 C) warmer than the mid-20th century baseline.  "We know the planet is absorbing more energy than it is emitting," said GISS Director James E. Hansen. "So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record."  The difference between 2011 and the warmest year in the GISS record (2010) is 0.22 degrees F (0.12 C). This underscores the emphasis scientists put on the long-term trend of global temperature rise. Because of the large natural variability of climate, scientists do not expect temperatures to rise consistently year after year. However, they do expect a continuing temperature rise over decades.

The first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century, Hansen said. The only year from the 20th century in the top 10 warmest years on record is 1998.  Higher temperatures today are largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide. These gases absorb infrared radiation emitted by Earth and release that energy into the atmosphere rather than allowing it to escape to space. As their atmospheric concentration has increased, the amount of energy "trapped" by these gases has led to higher temperatures.
The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.  The temperature analysis produced at GISS is compiled from weather data from more than 1,000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements. A publicly available computer program is used to calculate the difference between surface temperature in a given month and the average temperature for the same place during 1951 to 1980. This three-decade period functions as a baseline for the analysis.  The resulting temperature record is very close to analyses by the Met Office Hadley Centre in the United Kingdom and the National Oceanic and Atmospheric Administration's National Climatic Data Center in Asheville, N.C.  Hansen said he expects record-breaking global average temperature in the next two to three years because solar activity is on the upswing and the next El Niño will increase tropical Pacific temperatures. The warmest years on record were 2005 and 2010, in a virtual tie.  "It's always dangerous to make predictions about El Niño, but it's safe to say we'll see one in the next three years," Hansen said. "It won't take a very strong El Niño to push temperatures above 2010."

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