Blog Archive

Saturday, May 30, 2009

Ted Scambos, Eric Steig, Tom Neumann, IPY, U.S.-Norwegian South Pole Traverse


Photo credit:Lou Albershardt

IPY Traverse

Posted: May 6, 2009

Courtesy: Antarctic Sun

by Peter Rejcek

The 12 scientists and support staff who made a slow crawl across a vast, blank stretch of East Antarctica this past austral summer for three months to study how regional climate variability relates to global climate change expected to encounter brutally cold storms and other challenges on the high polar plateau.

They didn’t expect to come across other travelers in the relatively unexplored area known as Queen Maud Land. But they did — three times in one day.

“We were astonished because we were supposed to be all alone,” said Ted Scambos , a member of the Norwegian-U.S. science team that crossed a large slice of the Antarctic continent using tracked vehicles pulling sleds. “I don’t know where you can go in order to be on the edge of the Earth anymore.”

The encounters, all involving people taking part in a commercial race to the South Pole, occurred near a fuel depot in an area where the ice sheet was more than 3,000 meters thick, hiding at least four distinct subglacial bodies of water called the Recovery Lakes.

“Fuel depots in Antarctica are kind of the equivalent of watering holes in Africa,” mused Scambos, lead scientist at the Boulder, Colo.-based National Snow and Ice Data Center. “Everybody has to come to the fuel depot, and you see all kinds of people, all kinds of groups, gathered at the fuel depot.”

But for most of the roundtrip journey between Norway’s Troll research station on the coast and the U.S. Antarctic Program’s South Pole Station , the scientists and crew were on their own. They took measurements of the snow and ice in areas that virtually no one had visited since the late 1960s, when the United States primarily used tractor trains to conduct deep-field science work.

Living and working out of bright red, boxed buildings mounted on sleds, the team collected ice cores at various depths and locations, used radar to map the ice sheet layers and dug snow pits — all in an effort to understand the climate in this area for the last thousand years and how it may be changing today. The project was part of the International Polar Year , a 60-nation effort to better understand the Antarctic and Arctic, which officially ended last month.

“It’s really been a blank spot on the map — on both the literal map as well as the metaphoric map of climate change in Antarctica,” said Tom Neumann , leader of the traverse team during the second leg of the two-year project that began in 2007-08 and covered nearly 7,000 kilometers including a few side trips. “[The traverse] should help fill in the picture of how Antarctica overall is changing.”

Scientists had believed that Antarctica was largely bucking the global warming trend. While West Antarctica was undoubtedly heating up — particularly the outstretched tip of the Antarctic Peninsula where ice shelves are disappearing at historic rates — studies of the much larger East Antarctic Ice Sheet suggested a cooling trend.

Some researchers have suggested the depletion of stratospheric ozone over Antarctica — the ozone hole that appears each austral spring — is affecting atmospheric circulation and westerly winds around the continent, effectively shielding it from global warming. But a paper in the journal Nature earlier this year said warming in West Antarctica is greater than whatever cooling may be occurring on the rest of the ice-covered continent.

“Simple explanations don’t capture the complexity of climate,” explained Eric Steig , lead author of the Nature paper and a professor at the University of Washington , in a statement back in January.

“The thing you hear all the time is that Antarctica is cooling, and that’s not the case,” added Steig, a collaborator on the IPY traverse project. “If anything it’s the reverse, but it’s more complex than that. Antarctica isn’t warming at the same rate everywhere, and while some areas have been cooling for a long time, the evidence shows the continent as a whole is getting warmer.”

Antarctica is roughly the size of the United States and Mexico: Snow in Denver doesn’t mean a blizzard stretches all the way down to Mexico City. “Antarctica is a huge place, and I would be surprised if it was all doing the same thing,” said Neumann, a scientist now with NASA Goddard Space Flight Center .

Yet there’s even a hint that East Antarctica — well, at least one spot on that incomplete map — may be warming based on one initial experiment by the traverse team. Scambos deployed strings of highly sensitive “thermometers” called thermistors into two of the deeper ice core holes.

The temperature on the ice sheet surface changes with the weather, but the temperature deeper down changes very slowly as the climate changes. Neumann likens it to throwing a frozen turkey into the oven — not the best way to cook a turkey, for sure, but eventually the center starts to thaw and cook based on the long-term outside temperature.

“It takes a while for the ice at 90 meters to notice how the surface temperature has changed,” Neumann explained. At that depth, the ice temperature is determined by the average temperature of the last 50 years or so. The instruments will operate for the next several years, allowing the scientists to determine how surface temperature changes through time.

“The initial results do say these areas are warming,” Neumann said, stressing that the measurements are in the hundredths of a degree per year and the data still raw.

Scambos: Recovery Lakes region was likely marine embayment in distant past
Most of the scientific analysis is yet to come. Neumann and others on the team will use the ice core samples to conduct stable isotopic measurements. By studying the isotopic ratios of oxygen 16 and oxygen 18, for instance, researchers can figure out what the climate was doing at a particular time because different ratios indicate different types of climate.

The chemistry will help the team calibrate the radar returns of the ice layers, a key step to nailing the snow accumulation rates in East Antarctica — one part of the equation to whether the ice sheet is overall losing or gaining mass. Loss of mass would indicate a rise in sea level.

“The chemistry from the core helps because it tells you the accumulation rate at a point,” Neumann explained. “For example, how deep is the fallout from the 1960s above-ground nuclear testing? That information helps to calibrate the radar layers that intersect the core site.

“If a radar layer is shallower, then it has had relatively less accumulation; a deep layer reflects relatively more accumulation. The information form the core lets you quantify the ‘relative’ statements above.”

The scientists also took the opportunity to explore the Recovery Lakes, an area of at least four lakes at the head of one of the largest ice streams draining East Antarctica. Ranging in size from 600 to 1,500 square kilometers, at depths well below sea level, the lakes were likely part of a deep marine embayment millions of years ago when the ice sheet was much smaller, according to Scambos.

“It was probably dynamic in the past,” he said. “In the distant future, if the Earth gets a great deal warmer, it would be dynamic again. I would prefer to think that we’ll stabilize climate change before we have to worry about this part of Antarctica disintegrating.”

There is still a lot of uncertainty about what the Antarctic ice sheets may do in the future because so little of it has been measured, particularly compared to Greenland, according to Neumann.

“The uncertainties in Greenland are getting quite a lot smaller as we get more and more data about ice velocity, ice thickness and accumulation rate. It’s certainly negative [mass balance] and we know roughly how negative it is in Greenland,” he said. “Antarctica is a bit of a different story, because it is so much larger and there’s places with so much less data, such as in East Antarctica.

“The physical insight is coming along and the model development is coming along, but I think it’s going to be a quite a while before we really have confidence in the large-scale predictive models of ice sheet change,” he added.

More ground-based studies like the traverse would help to continue filling in the blank spots of the climate change map, according to the scientists. “Most of that uncertainty [about Antarctica] can be beaten down with more and more measurements of accumulation rates,” Neumann said.

“The traverse system that the Norwegians have put together is fantastic, state-of-the-art. It’s the best in the world right now in terms of supporting a science crew over long distances,” Scambos said. “They essentially have a mobile, 12-person base that provides them relatively easy access to a large area. … [Queen Maud Land is] one of the least-explored areas of Antarctica, and I think that’s going to change, in part, thanks to this traverse system they’ve got.”

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Friday, May 29, 2009

Aixue Hu et al., GRL, 36 (2009), Transient response of the MOC and climate to potential melting of the Greenland Ice Sheet in the 21st century

Geophysical Research Letters, 36, L10707; doi:10.1029/2009GL037998.

Transient response of the MOC and climate to potential melting of the Greenland Ice Sheet in the 21st century

Aixue Hu, Gerald A. Meehl (Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO, U.S.A.), Weiqing Han (Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, CO, U.S.A.), and Jianjun Yin (Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, U.S.A.)

(Received 3 March 2009; accepted 6 May 2009; published 29 May 2009.)


The potential effects of Greenland Ice Sheet (GrIS) melting on the Atlantic meridional overturning circulation (MOC) and global climate in the 21st century are assessed using the Community Climate System Model version 3 with prescribed rates of GrIS melting. Only when GrIS melting flux is strong enough to be able to produce net freshwater gain in upper subpolar North Atlantic does the MOC weaken further in the 21st century. Otherwise this additional melting flux does not alter the MOC much relative to the simulation without this added flux. The weakened MOC doesn't make the late 21st century global climate cooler than the late 20th century, but does reduce the magnitude of the warming in the northern high latitudes by a few degrees. Moreover, the additional dynamic sea level rise due to this weakened MOC could potentially aggravate the sea level problem near the northeast North America coast.

Link to abstract:

Thursday, May 28, 2009

NASA: Phytoplankton`s eerie red fluorescent glow shows ocean plant health

Eerie Red Glow Traces Ocean Plant Health

NASA, May 28, 2009: A unique signal detected by NASA's Aqua satellite is helping researchers check the health and productivity of ocean plants around the world.

Fluorescent red light emitted by ocean phytoplankton and detected by Aqua reveals how efficiently the microscopic plants are turning sunlight and nutrients into food through photosynthesis.

"This is the first direct measurement of the health of the phytoplankton in the ocean," says Michael Behrenfeld, a biologist at Oregon State University who specializes in marine plants. "We now have an important new tool for observing changes in phytoplankton all over the planet."

see caption

Above: Phytoplankton -- such as this colony of chaetoceros socialis -- naturally give off fluorescent light as they dissipate excess solar energy that they cannot consume through photosynthesis. Credit: Maria Vernet, Scripps Institution of Oceanography

The findings were published this month in the journal Biogeosciences and presented at a news briefing on May 28th.

Single-celled phytoplankton fuel nearly all ocean ecosystems, serving as the most basic food source for marine animals from zooplankton to fish to shellfish. In fact, phytoplankton account for half of all photosynthetic activity on Earth. The health of these marine plants affects commercial fisheries, the amount of carbon dioxide the ocean can absorb, and how the ocean responds to climate change.

Over the past two decades, scientists have employed various satellite sensors to measure the amount and distribution of the green pigment chlorophyll, an indicator of the amount of plant life in the ocean. But with the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite, scientists have now observed "red-light fluorescence" over the open ocean.

"Chlorophyll gives us a picture of how much phytoplankton is present," says Scott Doney, a marine chemist from the Woods Hole Oceanographic Institution and a co-author of the paper. "Fluorescence provides insight into how well they are functioning in the ecosystem."

All plants absorb energy from the sun, typically more than they can consume through photosynthesis. The extra energy is mostly released as heat, but a small fraction is re-emitted as fluorescent light in red wavelengths. MODIS is the first instrument to observe this signal on a global scale.

see caption

Above: A global map of red fluorescent light emitted by phytoplankton. Credit: Aqua/MODIS/Mike Behrenfeld, Oregon State University [Larger image]

Red-light fluorescence reveals much about the physiology of marine plants and the efficiency of photosynthesis, as different parts of the plant's energy-harnessing machinery are activated based on the amount of light and nutrients available.

For example, the amount of fluorescence increases when phytoplankton are under stress from a lack of iron, a critical nutrient in seawater. The iron needed for plant growth reaches the sea surface on winds blowing dust from deserts and other arid areas, and from upwelling currents near river plumes and islands. Fluorescence data from MODIS has allowed the research team to study these dynamics.

The Indian Ocean was a particular surprise, as large portions of the ocean were seen to "light up" seasonally with changes in monsoon winds. In the summer, fall, and winter – particularly summer – significant southwesterly winds stir up ocean currents and bring more nutrients up from the depths for the phytoplankton. At the same time, the amount of iron-rich dust delivered by winds is reduced.

see caption

Right: A map of fluorescent light emitted by plankton in the Indian Ocean, where seasonal monsoons can limit the amount of iron nutrients in the water and stress the plankton to emit more light. Credit: Aqua/MODIS/Mike Behrenfeld, Oregon State University

"On time-scales of weeks to months, we can use these data to track plankton responses to iron inputs from dust storms and the transport of iron-rich water from islands and continents," says Doney. "Over years to decades, we can also detect long-term trends in climate change and other human perturbations to the ocean."

Climate change could mean stronger winds pick up more dust and blow it to sea, or less intense winds leaving waters dust-free. Some regions will become drier and others wetter, changing the regions where dusty soils accumulate and get swept up into the air. Phytoplankton will reflect and react to these global changes.

"NASA satellites are powerful tools," says Behrenfeld. "Huge portions of the ocean remain largely unsampled, so the satellite view is critical to seeing the big picture."

Editor: Dr. Tony Phillips | Credit: Science@NASA

Credits: The research was funded by NASA and involved collaborators from the University of Maine, the University of California-Santa Barbara, the University of Southern Mississippi, NASA’s Goddard Space Flight Center, the Woods Hole Oceanographic Institution, Cornell University, and the University of California-Irvine.

NASA's Future: US Space Exploration Policy

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E.A.G. Schuur et al., Nature 459 (May 27, 2009):The effect of permafrost thaw on old carbon release and net carbon exchange from tundra

Nature 459, 556-559 (28 May 2009) | doi:10.1038/nature08031 (Received 24 August 2008, accepted 25 March 2009.)

The effect of permafrost thaw on old carbon release and net carbon exchange from tundra

Edward A. G. Schuur*1,4, Jason G. Vogel1,4, Kathryn G. Crummer1, Hanna Lee1, James O. Sickman2 and T. E. Osterkamp3

  1. Department of Biology, University of Florida, Gainesville, Florida 32611, USA
  2. Department of Environmental Science, University of California, Riverside, California 92521, USA
  3. Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775, USA
  4. These authors contributed equally to this work.

*Correspondence and requests for materials: e-mail:

Permafrost soils in boreal and Arctic ecosystems store almost twice as much carbon1, 2 as is currently present in the atmosphere3. Permafrost thaw and the microbial decomposition of previously frozen organic carbon is considered one of the most likely positive climate feedbacks from terrestrial ecosystems to the atmosphere in a warmer world1, 2, 4, 5, 6, 7. The rate of carbon release from permafrost soils is highly uncertain, but it is crucial for predicting the strength and timing of this carbon-cycle feedback effect, and thus how important permafrost thaw will be for climate change this century and beyond1, 2, 4, 5, 6, 7. Sustained transfers of carbon to the atmosphere that could cause a significant positive feedback to climate change must come from old carbon, which forms the bulk of the permafrost carbon pool that accumulated over thousands of years8, 9, 10, 11. Here we measure net ecosystem carbon exchange and the radiocarbon age of ecosystem respiration in a tundra landscape undergoing permafrost thaw12 to determine the influence of old carbon loss on ecosystem carbon balance. We find that areas that thawed over the past 15 years had 40% more annual losses of old carbon than minimally thawed areas, but had overall net ecosystem carbon uptake as increased plant growth offset these losses. In contrast, areas that thawed decades earlier lost even more old carbon, a 78% increase over minimally thawed areas; this old carbon loss contributed to overall net ecosystem carbon release despite increased plant growth. Our data document significant losses of soil carbon with permafrost thaw that, over decadal timescales, overwhelms increased plant carbon uptake13, 14, 15 at rates that could make permafrost a large biospheric carbon source in a warmer world.

Link to abstract:

Nature: Arctic thaw could prompt huge release of carbon dioxide

Arctic thaw could prompt huge release of carbon dioxide

But plant growth initially offsets permafrost carbon release

Arctic tundraMore plant growth will absorb some of the carbon dioxide emitted by a warmer Arctic.Punchstock

Thawing Arctic soils could release a billion tonnes of carbon every year by the end of this century, new evidence from test plots in Alaska suggests.

The study by researchers in the United States is one of the first to use radiocarbon dating to calculate the rate of carbon loss from melting tundra soils in situ.

"Previous studies have calculated carbon loss as tundra thaws in the laboratory," says Edward Schuur from the University of Florida in Gainesville, who led the research. "This study is different because we measured the ecosystem response in the real world."

Scientists have long debated how the global climate might be affected by thawing of the Arctic's permanently frozen soils, known as permafrost. When permafrost melts, microbes decompose organic matter in the soil, producing greenhouse gases. But when plants have access to warmer, deeper soils, they grow faster and take in carbon dioxide. Scientists have postulated that CO2 release by microbes would outweigh any greening of the Arctic by plant life, but the precise balance between the two was not known, says Schuur.

“It's a slow-motion time bomb.”

Edward Schuur

The study by Schuur and his colleagues, published today in Nature1, shows that after 15 years of thaw, plants initially grow faster and take in more carbon than is released by the melting tundra, so the ecosystem is an overall carbon sink. But after a few decades, the balance shifts and the ecosystem becomes a source of carbon.

"The plants are growing faster, but after a few decades the rate of carbon loss from the soils is so high the plants can't keep up," says Schuur.

It's estimated that permafrost soils store about twice as much carbon than is currently present in the atmosphere2, and the stores of carbon are unlikely to run out any time soon. "It's a slow-motion time bomb," says Schuur.

Ecosystem effects

Schuur's team determined how long each chosen test site had been thawing using long-term temperature data and historical aerial photographs. The long-term data enabled the group to determine the ecosystem response to thawing several years into the process, despite conducting the experiment over only three years.

The team calculated the total carbon lost or gained at each test site on the tundra owing to permafrost thaw, using an infrared gas analyser to measure CO2 concentrations.

The team then used radiocarbon dating to calculate the percentage of total lost or gained carbon that came from the permafrost. Because the isotope carbon-14 is subject to radioactive decay over time, lower levels of carbon-14 suggest it is 'old carbon' that has been locked away from the atmosphere in permafrost for hundreds or even thousands of years.

Extrapolations of the experimental findings to the whole Arctic region suggest that CO2 emissions from future permafrost thawing could be roughly a billion tonnes per year — of the same order of magnitude as emissions from current deforestation of the tropics. Burning of fossil fuels releases about 8.5 billion tonnes of CO2 a year.

"This represents an important finding for our predictions of what may happen to tundra ecosystems as the permafrost thawing progresses over the coming decades," says Torben Christensen, a biogeochemist at Lund University in Sweden.

But Christensen points out that future permafrost studies should include measurements of methane gas as well, because of its potential effects on global warming.

“These studies have to be made at other places.”

Martin Heimann
Max Planck Institute of Biogeochemistry

Martin Heimann from the Max Planck Institute of Biogeochemistry in Jena, Germany, adds that although Schuur's study might be accurate in describing his Alaskan test site, there are problems in extrapolating his results across the Arctic. "The Arctic is very heterogeneous," Heimann says. "These studies have to be made at other places."

Heimann also points out that the data from Schuur and his team show interannual variability, which makes it challenging to deduce long-term trends. "The measurements need to be conducted for decades," he says. "But it's a start.

Schuur, E. A. G. et al. Nature 459, 556–559 (2009). | Article |

Schuur, E. A. G. et al. Bioscience 58, 701–714 (2008). | Article |

Ted Schuur, NSF: Thawing permafrost will contribute significantly to atmospheric CO2, methane

Press Release 09-111
Arctic Tundra May Contribute to Warmer World

Researchers predict permafrost thaw will intensify climate change

National Science Foundation, May 27, 2009

A lot of old carbon is stored deep in the tundra where it is locked in permafrost. As these areas start to thaw over about 15 years, large ice wedges in the soil get smaller causing pot-holing and soil depression. The newly available water prompts faster plant growth, and the carbon taken out of the atmosphere by the plants photosynthesizing is greater than the carbon released back into the atmosphere by plants respiring and microbes decomposing carbon. However, after about 50 years, as thawing continues and the soil settles even more, plants are growing faster yet, however the rate of plant respiration and old carbon release through microbes grows even bigger netting more carbon out into the atmosphere than into the soil. Credit: Zina Deretsky, National Science Foundation.

View a video interview with ecologist Ted Schuur (clip1, clip2, clip3) of the University of Florida.

A study published in the May 28, 2009, issue of the journal Nature has helped define the potentially significant contribution of permafrost thaw to atmospheric concentrations of carbon, which have already reached unprecedented levels.

"In earlier work, we estimated that widespread permafrost thaw could potentially release 0.8-1.1 gigatons of carbon per year," said Ted Schuur, an ecologist at the University of Florida and the lead author of the study. "Before this study, we didn't know how fast that carbon could potentially be released from permafrost and how this feedback to climate would change over time."

A large amount of organic carbon in the tundra is stored in the soil and permafrost. This pool of carbon, deposited over thousands of years, remains locked in the perennially frozen ground. In recent years this area began to thaw, providing increased access to plants and microbes that could shift the carbon from the land to the atmosphere.

An understanding of the rate of carbon release is necessary to estimate the strength of positive feedback to climate change, a likely consequence of permafrost thaw. Scientists use the term positive feedback to describe the snowball effect described here: a warmer climate permits permafrost thaw, releasing more carbon into the atmosphere, which will further increase global surface temperature.

From 2004 to 2006, Schuur and his team used radiocarbon dating, a technique typically used to determine the age of artifacts, to track the movement of "old" organic carbon accumulated within the soils and permafrost at an Alaskan site. The ability to distinguish old carbon from newer carbon allowed the researchers to track current metabolism of old carbon in an area where permafrost thaw is increasing.

Surprisingly, this research revealed that during the initial stages of permafrost thaw, plant growth and photosynthesis, which remove carbon from the atmosphere, increase. This increase offsets the release of old carbon from thawing. However, sustained thaw eventually releases more carbon than plants can uptake, overwhelming their compensatory capacities. To put this in a global context, if the average global temperature continues to rise, current calculations predict that positive feedback from permafrost thaw could annually add as much carbon to the atmosphere as another significant source, land use change.

The Alaskan site where Schuur and colleagues carried out their research was monitored over the past two decades, with permafrost temperature measurements beginning before the permafrost began to thaw. This detailed record coupled with Schuur's study of ecosystem carbon exchange and old carbon release provide a comprehensive picture of the dynamics of carbon exchange in response to permafrost thaw.

"Records from this site exist on a decadal time scale, meaning we are able to more accurately account for the slow pace of change within the system. Overall, this research documents the long-term plant and soil changes that occur as permafrost thaws, thus providing a basis for making long term predictions about ecosystem carbon balance with increased confidence," Schuur reported.

Media Contacts
Lisa Van Pay, NSF (703) 292-8796
Lily Whiteman, NSF (703) 292-8070

Principal Investigators
Ted Schuur, University of Florida (352) 392-7913

Link to article:

NOAA: 2008 Arctic Report Card

red square Atmosphere
red square Sea Ice
yellow square Biology
yellow square Ocean
red square Greenland
yellow square Land
Warming (red) and mixed (yellow) signals

Atmosphere Atmosphere
5° C temperature increases were recorded in autumn
Ocean Ocean
Observed increase in temperature of surface and deep ocean layers
Sea ice Sea Ice
Near-record minimum summer sea ice extent
Greenland Greenland
Records set in both the duration and extent of summer surface melt
Biology Biology
Fisheries and marine mammals impacted by loss of sea ice
Land Land
Permafrost temperatures tend to increase, while snow extent tends to decrease

About the Report Card

Spring agricultural fires have large impact on melting Arctic

Spring agricultural fires have large impact on melting Arctic, May 26th, 2009

Scientists from around the world will convene at the University of New Hampshire June 2-5, 2009, to discuss key findings from the most ambitious effort ever undertaken to measure "short-lived" airborne pollutants in the Arctic and determine how they contribute in the near term to the dramatic changes underway in the vast, climate-sensitive region.

The two-year international field campaign known as POLARCAT was conducted most intensively during two three-week periods last spring and summer and focused on the transport of pollutants into the Arctic from lower latitudes.

One surprise discovery was that large-scale agricultural burning in Russia, Kazakhstan, China, the U.S., Canada, and the Ukraine is having a much greater impact than previously thought.

A particular threat is posed by springtime burning - to remove crop residues for new planting or clear brush for grazing - because the or soot produced by the fires can lead to accelerated melting of snow and ice.

Soot, which is produced through incomplete of and fossil fuels, may account for as much as 30 percent of Arctic warming to date, according to recent estimates. Soot can warm the surrounding air and, when deposited on ice and snow, absorb solar energy and add to the melting process.

In addition to soot, other short-lived pollutants include ozone and methane. Although global warming is largely the result of excess accumulation of carbon dioxide, the Arctic is highly sensitive to short-lived pollutants. Forest fires, agricultural burning, primitive cookstoves, and are the primary sources of black carbon; oil and gas activities and landfills are major sources of methane.

During the UNH workshop, a report by the Clean Air Task Force detailing some of the campaign's findings on agricultural burning and transport to the Arctic will be officially released.

"Targeting these emissions offers a supplemental and parallel strategy to carbon dioxide reductions, with the advantage of a much faster temperature response, and the benefit of health risk reductions," says Ellen Baum, senior scientist of the Clean Air Task Force. "In addition, we have the know-how to control these pollutants today."

The report notes that during April, at the beginning portion of the field campaign in Northern Alaska, aircraft-based researchers were surprised to find 50 smoke plumes originating from fires in Eurasia more than 3,000 miles away. Analysis of the plumes, combined with satellite images, revealed the smoke came from agricultural fires in Northern Kazakhstan-Southern Russia and from in Southern Siberia. The emissions from fires far outweighed those from , the report states.

"These fires weren't part of our standard predictions, they weren't in our models," says Daniel Jacob, a professor of atmospheric chemistry and environmental engineering at Harvard. Jacob participated in a portion of the campaign known as ARCTAS, which used NASA's DC-8 "flying laboratory" to sample plumes of air over Arctic regions in Alaska and Canada.

The international team of scientists used satellites, instrumented aircraft, ocean-going ships, and ground stations to track and analyze pollution transported into the region.

UNH atmospheric chemist Jack Dibb of the Institute for the Study of Earth, Oceans, and Space was also on the DC-8. "We're in agreement that these short-lived pollutants are critical in the Arctic. This meeting is to discuss what we learned from this massive undertaking and what we as a scientific community can recommend to help address the problem," says Dibb.

The work presented at the POLARCAT meeting will benefit the eight-country Arctic Council, which recently voted to jointly undertake efforts to reduce emissions of black carbon, ozone precursors, and methane in order to slow climate change and ice melt in the Arctic. The data will provide more robust results for governments to use in the development of mitigation efforts with the highest likelihood of benefiting Arctic climate.

"Accelerated warming is unraveling the ecosystems of the region," says Brooks Yeager, executive vice president of Clean Air-Cool Planet.

"Pollutants carried into the region help drive this unprecedented warming and melting, which makes this new science so very valuable, pinpointing as it does the sources and the solutions."

Link to article:

Burning farmland deposits carbon black on Arctic - from southern Russian, Siberia, & northern Kazakhstan

Burning crops darken Arctic sky, speed polar melt

The collapse of the Soviet Union and the loosening of state control over crop burning in Russia has had an unexpected impact in the Canadian North: the unleashing of massive amounts of soot that is settling on Arctic sea ice and speeding the ongoing polar meltdown.

How the end of the Cold War has fuelled Arctic warming is detailed in a new report by U.S. scientists that points a finger at Saskatchewan farmers for sending some "black carbon" into the Arctic environment but largely blames Russia for the rising number of smoke plumes drifting north and creating a "critical" challenge for Canada and other polar nations.

The findings were released ahead of an international meeting next week at the University of New Hampshire aimed at curbing the impact of agricultural burning — a problem scientists say has emerged as a major factor in Arctic warming and thinning sea ice.

"These fires weren't part of our standard predictions, they weren't in our models," said Daniel Jacob, a Harvard University climate researcher who participated in a multi-agency U.S. government experiment last spring off the northern coast of Alaska.

Teams of scientists led by NASA, the National Oceanic and Atmospheric Administration and the U.S. Department of Energy gathered data on long-range polar pollutants and used NASA's DC-8 "flying laboratory" to sample smoke plumes drifting over Alaska and parts of Arctic Canada.

"What they found surprised them," says the report, Agricultural Fires and Arctic Climate Change, released Wednesday by the Boston-based Clean Air Task Force.

"Over the course of the month, the airplanes encountered up to 50 smoke plumes originating from fires in Eurasia, more than 4,800 kilometres away. Analysis of the plumes, combined with satellite images, revealed the smoke came from agricultural fires in Northern Kazakhstan-Southern Russia and from forest fires in Southern Siberia."

Forest fires have long been identified as a major source of Arctic pollutants, but the study concludes that agricultural fires — typically used to clear stubble from harvested crops and prepare land for the next growing season — are sending more and more smoke northward, warming the Arctic troposphere and then depositing soot on polar snow and sea ice.

The darkened surface reduces the reflective features of the snow and ice and absorbs more heat from the sun, compounding the overall effects of rising temperatures caused by global climate change, the report states.

The study attributes much of the rise in farm-related Arctic pollution to changing land-use practices in post-Soviet Russia and Kazakhstan.

"The collapse of the USSR in 1991 brought an end to the socialist command economy that had dominated agricultural production for decades," the report states. "In the absence of state subsidies, the large farming co-operatives that had supported Soviet industrial society were abandoned, leading to the re-growth of vegetation across much of the countryside. As smaller private enterprises emerged, they faced a changed landscape; cultivated fields now existed alongside wild grasslands and dry brush, creating ideal conditions for fire."

The report says the largely unregulated use of agricultural fires in Russia is now responsible for about 80% of the crop-related black carbon reaching the Arctic.

Canada is contributing just over 1% of the total, the report notes, with most of those agricultural emissions coming from Saskatchewan.

Although farmland burning appears to have declined in recent years in the province, satellite records "nevertheless show extensive fire activity in the crop and grasslands of southern Saskatchewan between January and June 2008," the report says.

The U.S. researchers say the findings about the impact of agricultural fires should prompt stronger action from the Arctic Council, an eight-country organization that includes Russia and Canada and which recently pledged to curb black carbon emissions reaching polar latitudes.

"Targeting these emissions offers a supplemental and parallel strategy to carbon dioxide reductions, with the advantage of a much faster temperature response, and the benefit of health risk reductions," says Ellen Baum, senior scientist of the Clean Air Task Force. "In addition, we have the know-how to control these pollutants today."

Another U.S. study announced on Wednesday also had bad news for the Arctic.

A University of Florida-led research paper to be published in the journal Nature predicted that thawing Arctic permafrost will pump one billion tonnes of carbon dioxide annually into the atmosphere by the end of this century.

Although greater plant growth in the warming Arctic will absorb more CO2 and initially balance the effects of melting permafrost, the research shows the increased vegetation won't fully compensate for carbon unlocked from the soil.

"At first, with the plants offsetting the carbon dioxide, it will appear that everything is fine, but actually this conceals the initial destabilization of permafrost carbon," said study co-author Ted Schurr in a statement released by the university. "But it doesn't last, because there is so much carbon in the permafrost that eventually the plants can't keep up."

A third study — on projected sea-level rises caused by melting Arctic ice — identified coastal cities in the northeast corner of North America, including Halifax, New York and Boston, as the places most likely to face adverse effects.

The study led by the National Center for Atmospheric Research at the University of Colorado incorporated forecasted effects from melting of the Greenland Ice Sheet with earlier predictions about overall increases in ocean levels caused by global warming.

The study, to be published this week in the journal Geophysical Research Letters, found that continued moderate melting of Greenland's ice cap would shift Atlantic Ocean circulation by the end this century and cause sea levels in northeastern Canada and the U.S. to increase between 30 and 51 cm more than in other coastal zones.

"If the Greenland melt continues to accelerate, we could see significant impacts this century on the northeast U.S. coast from the resulting sea level rise," said NCAR scientist Aixue Hu. "Major northeastern cities are directly in the path of the greatest rise."

The researchers also note that "more remote areas in extreme northeastern Canada and Greenland could see even higher sea-level rise" than heavily populated areas to the south.

Those areas include much of Ellesmere Island, Baffin Island, Quebec's Ungava Peninsula and Labrador.

Aixue Hu, Gerald Meehl, Weiqing Han & Yianjun Yin, GRL, Greenland ice sheet melt to cause more sea level rise along northeast U.S., Canada

Melting Greenland Ice Sheet may threaten northeast United States, Canada

This visualization (click to enlarge details), based on new computer modeling, shows that sea level rise may be an additional 10 centimeters (4 inches) higher by populated areas in northeastern North America than previously thought. Extreme northeastern North America and Greenland may experience even higher sea level rise. (Credit: Graphic courtesy Geophysical Research Letters, modified by UCAR)

ScienceDaily (May 28, 2009) — Melting of the Greenland ice sheet this century may drive more water than previously thought toward the already threatened coastlines of New York, Boston, Halifax, and other cities in the northeastern United States and Canada, according to new research led by the National Center for Atmospheric Research (NCAR).

The study, which is being published May 29, 2009, in Geophysical Research Letters, finds that if Greenland's ice melts at moderate to high rates, ocean circulation by 2100 may shift and cause sea levels off the northeast coast of North America to rise by about 12-20 inches (about 30-50 cm) more than in other coastal areas. The research builds on recent reports that have found that sea level rise associated with global warming could adversely affect North America, and its findings suggest that the situation is more threatening than previously believed.

"If the Greenland melt continues to accelerate, we could see significant impacts this century on the northeast U.S. coast from the resulting sea level rise," says NCAR scientist Aixue Hu, the lead author. "Major northeastern cities are directly in the path of the greatest rise."

A study in Nature Geoscience in March warned that warmer water temperatures could shift ocean currents in a way that would raise sea levels off the Northeast by about 8 inches (20 cm) more than the average global sea level rise. But it did not include the additional impact of Greenland's ice, which at moderate to high melt rates would further accelerate changes in ocean circulation and drive an additional 4 to 12 inches (about 10-30 cm) of water toward heavily populated areas of northeastern North America on top of average global sea level rise. More remote areas in extreme northeastern Canada and Greenland could see even higher sea level rise.

Scientists have been cautious about estimating average sea level rise this century in part because of complex processes within ice sheets. The 2007 assessment of the Intergovernmental Panel on Climate Change projected that sea levels worldwide could rise by an average of 7-23 inches (18-59 cm) this century, but many researchers believe the rise will be greater because of dynamic factors in ice sheets that appear to have accelerated the melting rate in recent years.

The new research was funded by the U.S. Department of Energy and by NCAR's sponsor, the National Science Foundation. It was conducted by scientists at NCAR, the University of Colorado at Boulder, and Florida State University.

How much meltwater?

To assess the impact of Greenland ice melt on ocean circulation, Hu and his coauthors used the Community Climate System Model, an NCAR-based computer model that simulates global climate. They considered three scenarios: the melt rate continuing to increase by 7% per year, as has been the case in recent years, or the melt rate slowing down to an increase of either 1 or 3% per year.

If Greenland's melt rate slows down to a 3% annual increase, the study team's computer simulations indicate that the runoff from its ice sheet could alter ocean circulation in a way that would direct about a foot of water toward the northeast coast of North America by 2100. This would be on top of the average global sea level rise expected as a result of global warming. Although the study team did not try to estimate that mean global sea level rise, their simulations indicated that melt from Greenland alone under the 3% scenario could raise worldwide sea levels by an average of 21 inches (54 cm).

If the annual increase in the melt rate dropped to 1%, the runoff would not raise northeastern sea levels by more than the 8 inches (20 cm) found in the earlier study in Nature Geoscience. But if the melt rate continued at its present 7% increase per year through 2050 and then leveled off, the study suggests that the northeast coast could see as much as 20 inches (50 cm) of sea level rise above a global average that could be several feet. However, Hu cautioned that other modeling studies have indicated that the 7% scenario is unlikely. [BLOGGER HERE: how many times have we heard this, only to be told later that the model was too conservative?]

In addition to sea level rise, Hu and his co-authors found that if the Greenland melt rate were to defy expectations and continue its 7% increase, this would drain enough fresh water into the North Atlantic to weaken the oceanic circulation that pumps warm water to the Arctic. Ironically, this weakening of the meridional overturning circulation (MOC) would help the Arctic avoid some of the impacts of global warming and lead to at least the temporary recovery of Arctic sea ice by the end of the century.

Why the Northeast?

The northeast coast of North America is especially vulnerable to the effects of Greenland ice melt because of the way the meridional overturning circulation acts like a conveyer belt transporting water through the Atlantic Ocean. The circulation carries warm Atlantic water from the tropics to the north, where it cools and descends to create a dense layer of cold water. As a result, sea level is currently about 28 inches (71 cm) lower in the North Atlantic than the North Pacific, which lacks such a dense layer.

If the melting of the Greenland Ice Sheet were to increase by 3 or 7% yearly, the additional fresh water could partially disrupt the northward conveyor belt. This would reduce the accumulation of deep, dense water. Instead, the deep water would be slightly warmer, expanding and elevating the surface across portions of the North Atlantic.

Unlike water in a bathtub, water in the oceans does not spread out evenly. Sea level can vary by several feet from one region to another, depending on such factors as ocean circulation and the extent to which water at lower depths is compressed.

"The oceans will not rise uniformly as the world warms," says NCAR scientist Gerald Meehl, a co-author of the paper. "Ocean dynamics will push water in certain directions, so some locations will experience sea level rise that is larger than the global average.

Aixue Hu, Gerald Meehl, Weiqing Han, & Jianjun Yin. Transient response of the MOC and climate to potential melting of the Greenland Ice Sheet in the 21st century. Geophysical Research Letters, May 29, 2009. DOI: 10.1029/2009GL037998

Wednesday, May 27, 2009

Stephen H. Schneider: San Francisco Examiner interview regarding global warming and climate change issues

by Thomas Fuller, SF Environmental Policy Examiner, May 24, 2009

This is part one of an interview with Professor Stephen Schneider regarding global warming and climate change issues.

Update: Roger Pielke, Sr., principal contributor to Climate Science, has commented both here and on his website regarding my classification of his weblog as a 'skeptic' weblog. I plead guilty to over-facile classification. Although Climate Science does regularly challenge the accepted wisdom of climate change activists, he is first and foremost a scientist who publishes regularly in peer-reviewed journals. As I have noted before here, one of the major themes pursued on Climate Science is that humans do influence the climate through deforestation, land-use policy and interruptions of the hydrologic cycle, and Pielke Sr. thinks that this may actually outweigh the effects of human emissions of CO2.

Mr. Pielke feels that being characterized as a skeptic is pejorative--and it is certainly used that way in many discussions. I guess I've developed a tough skin after being called much worse--to me it's the use of the term denier that sets me off. But it's essentially lazy writing, and I apologize. I actually have the highest respect for what I've seen of his work on his website and elsewhere.

I'll be pursuing this further--sadly, Mr. Pielke didn't provide an e-mail address and the comments section of his blog are usually turned off. I will try and contact him but in the meantime, I apologise for any confusion.

The second participant in the Global Warming Debates here at is Professor Stephen Schneider, whose biography runs longer than many of my articles. Here’s an excerpt:

Stephen H. Schneider is the Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies, Professor of Biology, and a Senior Fellow in the Woods Institute for the Environment at Stanford University. He served as an NCAR scientist from 1973-1996, where he co-founded the Climate Project. He focuses on climate change science, integrated assessment of ecological and economic impacts of human-induced climate change, and identifying viable climate policies and technological solutions. He has consulted for federal agencies and White House staff in seven administrations. Elected to the US National Academy of Sciences in 2002, Dr. Schneider received the American Association for the Advancement of Science/ Westinghouse Award for Public Understanding of Science and Technology and a MacArthur Fellowship for integrating and interpreting the results of global climate research. He is actively engaged in improving public understanding of science and the environment through extensive media communication and public outreach.

Conducting an interview by email can be dangerous—especially when a journalist is interviewing someone with a publication record as long as Professor Schneider’s. When he tosses three articles at me in response to a question, it, umm, means I have to read them. So. In this interview, I will indicate which of his answers come to us directly via email and which are from previously published sources. Part 1 is completely composed of his email responses.

The first part of our interview is concerned with what is happening now, in May of 2009, regarding climate science and the political debate surrounding it.

Via email:

How would you characterise the state of play regarding scientific discussion regarding anthropogenic contributions to global warming? What is happening in science today that bears on the debate?

Not much change over the past few decades, except nature is cooperating with theory as formerly theoretical projections like heat waves and ice melt is now observed--at faster rates than predicted. All in IPCC and NAS reports. Why ice is melting faster than the models suggest is still not known, but certainly not encouraging!

More specifically, the principal skeptic websites (Watt's Up With That, Climate Skeptic, Climate Audit and Climate Science) that I look at regularly seem to think they are winning the day. They think data is coming in that questions the established paradigm.

They have been thinking that as long as I have observed them and they have very few mainstream climate scientists who publish original research in climate refereed journals with them--a petroleum geologist's opinion on climate science is a as good as a climate scientists opinion on oil reserves. So petitions sent to hundreds of thousands of earth scientists are frauds. If these guys think they are "winning" why don't they try to take on face to face real climatologists at real meetings--not fake ideology shows like Heartland Institute--but with those with real knowledge--because they'd be slaughtered in public debate by Trenberth, Santer, Hansen, Oppenheimer, Allen, Mitchell, even little ol' me. It’s easy to blog, easy to write op-eds in the Wall Street Journal.

In terms of U.S. energy policy, do you favor a cap and trade for emissions or a carbon tax? More specifically do you have an opinion on the cap and trade legislation currently under consideration?

They can be made equivalent with good implementation rules. I wrote at Kyoto I preferred a tax and recycle idea--still kind of do, but we need a shadow price on carbon regardless of mechanism--I'll attach my Kyoto editorial on this. (And we’ll look at it in Part II of this interview.)

In general terms, how would you characterise President Obama's energy policy? Is it pointed in the right direction, are the priorities roughly in balance, are the numbers adequate?

He is trying to reverse a big ship headed at a reef—it will take a long time and lots of compromising.

A variety of extreme events have been postulated during the debate about global warming: The death or reversal of the Gulf stream, very rapid melting of the ice covering Greenland or Antarctica leading to dramatic sea level rise, the spread of malaria to areas where it does not currently exist as a threat, etc. How realistic are these potential events? 50%? 10%? 5%? 1%? 0.1%?

These are subjective probabilities since there is very little clear empirical base to go on--and since the future by definition has no data before the fact. all are plausible at some probability above that for buying fire insurance--a few percent--and some like Greenland melt seem to be many tens of percent likely for warming much over another degree C.

Why don't Americans care about global warming? Only a third think humans are responsible for it, and most rate it last on a list of concerns.

That is one recent poll--others are not that weak, but it is true of the priority rating. People are confused by a phony media debate in which very dissimilar quality "sides" are given equal time and credibility that average people cannot judge easily. It confuses more than enlightens and thus creates a wait and see response. That is why we have expert assessments to sort out real knowledge from easy claims from special interests on all sides.

What is your best guess as to what will be the progress of temperatures over this century? Which IPCC scenario do you think will play out and what will temperatures be in 2050 and 2100?

No pinned down idea—I have a factor of at least three of uncertainty--as I say in all my writings--I'll attach some. (He did—sigh.) My best guess, 2-4 °C warming by 2100, but if we're very lucky a bit less--and if very unlucky, even more.

Part 2 will look more deeply at the science and will refer to some of Professor Schneider’s more than 500 publications in scientific journals.

Thomas Fuller is an Examiner from San Francisco. You can see Thomas's articles on Thomas's Home Page.

Link to interview:

Gordon G. Chang, Forbes, We have a Chinese problem, not a North Korean one. If it weren't for Beijing, Pyongyang would be impotent

We have a Chinese problem, not a North Korean one

If it weren't for Beijing, Pyongyang would be impotent.

Gordon G. Chang

by Gordon G. Chang, Forbes, May 25, 2009

Hours after the Democratic People's Republic of Korea detonated its second atomic device, Beijing condemned the test. "The DPRK conducted another nuclear test in disregard of the common opposition of the international community," a Foreign Ministry statement, issued May 25, noted. "The Chinese government is firmly opposed to this act."

Is that so? Today, China supplies about 90% of North Korea's oil, 80% of its consumer goods and 45% of its food. Beijing is Pyongyang's only formal military ally and its primary backer in the United Nations Security Council and other diplomatic forums. If it weren't for the Chinese, there would be no North Korean missile program, no North Korean nuclear program and no North Korea.

Kim Jong Il, Pyongyang's coldly rational leader, knows he could not survive the loss of China's material and diplomatic support. If Chairman Kim doesn't appear to listen to his sponsors in Beijing in every instance, it's largely because they don't expect obedience each and every time. The Chinese pursue their plan of supporting the North because they know they have influence and can use it at any moment. Kim detonated a nuclear weapon in the last few hours because he knew the Chinese did not object to him doing so. He would not dare cross Beijing on a matter of such critical importance.

For the last eight years, the United States has had a Korea policy that can be described in one word: China. President Bush looked to Beijing to contain Pyongyang and disarm Kim. Yet during his administration the Chinese gave the North Korean leader the one thing he needed most to develop nuclear weapons and the missiles to deliver them: time. The Chinese counseled patience while the so-called six-party talks, which began in 2003, dragged on, but they failed to broker a solution even though they could have done so.

Many Chinese officials, especially in the Foreign Ministry, know their country's Korea policy is counterproductive in the long run because it will eventually lead to the nuclearization of the region and thereby the marginalization of Beijing's relative power. Yet there is no consensus in the upper echelons of the Communist Party and the People's Liberation Army to change long-held policies. Apparently, President Hu Jintao finds Kim useful in the short-term for keeping Japan and South Korea off-balance and in extracting concessions from the United States.

Today, President Obama said North Korea's acts "pose a grave threat to the peace and stability of the world." So what should his administration do? From all accounts, his senior Asia officials feel the United States has no leverage on Beijing. That assessment could not be more wrong. The legitimacy of the Chinese political system rests largely on the continual delivery of prosperity, and that prosperity depends on access to the American market.

In 2008, all but $29.2 billion of China's overall trade surplus of $295.5 billion related to sales to the United States. In 2007, all but $5.9 billion of the overall surplus of $262.2 billion was attributable to sales to America. The United States relies on Beijing to buy American debt, but the Chinese export machine cannot function if China does not buy our obligations. If Beijing does not do so, it will further constrain the American economy. If Beijing further constrains the American economy, Americans will be able to buy even fewer Chinese goods than they are at the moment. If Americans buy fewer Chinese goods, the Chinese economy will fall even faster than it is doing so now. And if the Chinese economy declines any faster, the country's political system will face increased tensions and difficulties.

So the White House has leverage, especially because the balance of power in Asia has shifted decisively toward the United States. In the past, Beijing could stand behind Pyongyang because Tokyo and the so-called "progressive" governments in Seoul--first under Kim Dae-jung and then Roh Moo-hyun--were doing the same. In short, the Japanese and South Koreans, Washington's two principal allies in the region, were giving the Chinese cover to continue with their long-time program of supporting the North.

Yet China's cover did not last. First Japan under Prime Minister Shinzo Abe and then South Korea under President Lee Myung-bak got out of the business of propping up Chairman Kim Jong Il. That has left Beijing alone in its support of the abhorrent regime in Pyongyang. In the past, the Chinese have defied Washington when they had company but were almost always cooperative when they did not.

Unfortunately, the Bush White House did not take advantage of changing circumstances in Asia and was unwilling to make China choose between its future--cooperation with the United States and the international community--and its past--relations with Kim's Korea. Today, the Obama administration is making the same fundamental mistake.

President Obama will never have a successful Korea policy until he has a successful Chinese one. North Korea can continue to defy the international community as long as it has Beijing's support. So we don't have a North Korea problem. We have a China one.

Gordon G. Chang is the author of The Coming Collapse of China.

Link to article:

Friday, May 22, 2009

Joseph Romm: M.I.T. doubles its 2095 warming projection to 10 °F — with 866 ppm and Arctic warming of 20 °F


M.I.T. doubles its 2095 warming projection to 10 °F — with 866 ppm and Arctic warming of 20 °F

Today's question: How the heck does the Greenland ice sheet survive accelerated disintegration from projected 20 °F warming by the 2090s?

I previously blogged on how the Massachusetts Institute of Technology Joint Program on the Science and Policy of Climate Change has joined the climate realists — the growing group of scientists who understand that the business as usual emissions path leads to unmitigated catastrophe (see "Hadley Center: "Catastrophic" 5-7 °C warming by 2100 on current emissions path" and below).

Back in January, the Program issued a remarkable report in January, by over a dozen leading experts, doubling their 2095 warming projection to 5.2 °C. The media mostly ignored it, which is no surprise, since the media generally ignores the realists in general (see U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories (or even worse) are being realised” — 1000 ppm

Now, the MIT study has been published in a peer-reviewed journal -- The American Meteorological Society's Journal of Climate (subs. req'd) -- which obviously it makes it much more credible and high-profile. Reuters has a good story on it, "Global warming could be twice as bad as forecast." The study concludes:

The MIT Integrated Global System Model is used to make probabilistic projections of climate change from 1861 to 2100. Since the model's first projections were published in 2003 substantial improvements have been made to the model and improved estimates of the probability distributions of uncertain input parameters have become available. The new projections are considerably warmer than the 2003 projections, e.g., the median surface warming in 2091 to 2100 is 5.2 °C compared to 2.4 °C in the earlier study. Many changes contribute to the stronger warming; among the more important ones are taking into account the cooling in the second half of the 20th century due to volcanic eruptions for input parameter estimation and a more sophisticated method for projecting GDP growth which eliminated many low emission scenarios.

[Note: That rise is compared to 1981-2000 temperature levels. So you can add at least 0.5 °C and 1.0 °F for comparison with pre-industrial temperatures, which I did in the headline -- see "A (Hopefully) Clarifying Note on Temperature."]

The MIT press release calls for "rapid and massive" action to avoid this. Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT's Center for Global Change Science, says, it is important "to base our opinions and policies on the peer-reviewed science... There's no way the world can or should take these risks." Duh!

Their median projection for the atmospheric concentration of carbon dioxide in 2095 is a jaw-dropping 866 ppm.


Projected decadal mean concentrations of CO2. Red solid lines are median, 5% and 95% percentiles for present study: dashed blue line the same from their 2003 projection.

As grim as this prediction is, it is still almost certainly an underestimate of what will happen on our current path of unrestricted greenhouse gas emissions, as Prinn explains:

And the odds indicated by this modeling may actually understate the problem, because the model does not fully incorporate other positive feedbacks that can occur, for example, if increased temperatures caused a large-scale melting of permafrost in arctic regions and subsequent release of large quantities of methane, a very potent greenhouse gas. Including that feedback "is just going to make it worse," Prinn says.

Speaking of feedbacks, the model shows staggering warming near the poles (see “What exactly is polar amplification and why does it matter?"):

Figure 9: Latitudinal distribution of changes in SAT in the last decade of 21st century relative to 1981-2000. Red solid lines are median, 5% and 95% percentiles for present study: dashed blue line the same from Webster et al. (2003).

Median arctic warming -- north of 70° latitude -- (from 1981-2000 levels) is 20 °F! How could Greenland's ice sheet possibly survive that?

Why the change in the 2009 modeling, compared to 2003? The Program's website explains:

There is no single revision that is responsible for this change. In our more recent global model simulatations, the ocean heat-uptake is slower than previously estimated, the ocean uptake of carbon is weaker, feedbacks from the land system as temperature rises are stronger, cumulative emissions of greenhouse gases over the century are higher, and offsetting cooling from aerosol emissions is lower. No one of these effects is very strong on its own, and even adding each separately together would not fully explain the higher temperatures. Rather than interacting additively, these different affects appear to interact multiplicatively, with feedbacks among the contributing factors, leading to the surprisingly large increase in the chance of much higher temperatures.

The carbon sinks are saturating, and the amplifying feedbacks are worse than previously thought -- that, of course, is a central understanding of all climate realists (see Study: Water-vapor feedback is "strong and positive," so we face "warming of several degrees Celsius" for links to the various feedbacks that have been ignored by most climate models).

Andrew Freedman at had one of the very few stories on this important study back in February and reprints this useful figure from MIT:


He explains:

Results of the studies are depicted online in MIT's "Greenhouse Gamble" exercise that conveys the "range of probability of potential global warming" via roulette wheel graphics (shown above). The modeling output showed that under both a "no policy" scenario and one in which nations took action beginning in the next few years to reduce greenhouse gas emissions, the odds have shifted in favor of larger temperature increases.
For the no policy scenario, the researchers concluded that there is now a nine percent chance (about one in 11 odds) that the global average surface temperature would increase by more than 7 °C (12.6 °F) by the end of this century, compared with only a less than one percent chance (one in 100 odds) that warming would be limited to below 3 °C (5.4 °F).

To repeat, on our current emissions path, we have a 9% chance of an incomprehensibly catastrophic warming of 7 °C by century's end, but less than a 1% chance of under 3 °C warming.

"The take home message from the new greenhouse gamble wheels is that if we do little or nothing about lowering greenhouse gas emissions that the dangers are much greater than we thought three or four years ago," said Ronald G. Prinn, professor of atmospheric chemistry at MIT. "It is making the impetus for serious policy much more urgent than we previously thought."

The time to act is now.

Link to article: