House Science, Space, and Technology Committee
Oversight Subcommittee
Disappearing Polar Bears and Permafrost: Is a Global Warming Tipping Point Embedded in the Ice?
On Wednesday, October 17, 2007, the Investigations and Oversight Subcommittee will hold a hearing on the impacts of global warming on the Arctic. This hearing will provide the Committee with an opportunity to hear from witnesses on three interrelated matters: (1) the current situation in the Arctic, including the situation facing the polar bear, (2) ways in which warming in the Arctic may accelerate global warming, especially through the emission of more greenhouse gases, and (3) interim steps that could be taken to reduce greenhouse gas emissions while the Congress weighs more elaborate carbon trade or tax proposals.
One of the themes that should emerge from this hearing is that, from a layman’s perspective, the models used to project climate change and its ramifications appear to be conservative in their projections. This is because any phenomena that are not understood well enough to be represented in models with confidence are excluded. These other phenomena may accentuate or depress warming trends. In the case of the Arctic, most of the phenomena that have been excluded from the models are believed to accentuate warming and its effects. Few will depress it. The modeling on polar bear survival, for example, uses projections from the IPCC models to estimate future changes in sea ice extent. Since the bears’ condition is very dependent upon both the extent of the sea ice and the duration of ice-free periods, projections of the bear survival are very dependent upon projections of sea ice. This summer the sea ice extent is far less than projected by the models.
The Center for Biological Diversity will appear to provide some advice on steps that can be taken to reduce warming, with particular emphasis on their efficacy in the Arctic. Among the steps they advocate are programs to reduce methane emissions and “black carbon.” Black carbon is soot that, in the Arctic, has a particularly pernicious effect. When it is deposited on snow and ice it decreases its reflectivity and increases its heat absorption leading to greater melting. As the Arctic comes under more and more industrialization with other warming, one could anticipate further production of black carbon. Methane is a powerful greenhouse gas, with an estimated global warming potential 23 times greater than carbon dioxide over a 100-year time frame. Methane is a precursor to tropospheric ozone. In that form, it traps shortwave radiation as it enters the earth’s atmosphere from the sun and then when it is reflected back again by snow and ice. As a consequence, its impact is strongest over the poles. Reducing global methane emissions would provide a particular benefit to the Arctic.
- Dr. Richard Alley, Evan Pugh Professor of Geosciences, Pennsylvania State University, Department of Geosciences
- Dr. Glenn Juday, Professor, University of Alaska at Fairbanks, School of Natural Resources and Agricultural Sciences
- Dr. Sue Haseltine, Associate Director for Biology, U.S. Geological Survey, U.S. Department of Interior
- Kassie R. Siegel, Director, Center for Biological Diversity, Climate, Air and Energy Program
10:40: Juday They are self-reliant people, and their environment is changing. Pack ice should be present right about now, and they’re not able to be safely on the ice. The permafrost definitely is warming. The boreal forest is dying. Sea ice is retreating and thinning.
10:45: Haseltine Data shows a decline of about 10% per decade in sea ice extent. This year had about 40% less ice than 1979. There’s a growing scientific concern that sea ice has been pushed past a threshhold of catastrophic change.
10:51: Siegel The polar bear will likely be listed as endangered in the next year, but the listing won’t be enough to save the polar bear or the sea ice they depend on. The polar bear depends on sea ice. The situation for polar bears in a rapidly warming Arctic is grim. We know that business as usual cannot continue and we need to limit CO2 concentrations to below 450 PPM. Anything else we do may be futile if we don’t address this most important of greenhouse gases. By attacking methane and black carbon emissions we can have an immediate effect on the Arctic and give ourselves a chance to save the polar bear in the long term. According to conservative estimates of the EPA we can eliminate 70 million metric tons of CO2 equivalent methane with no-cost or cost-benefit actions.
11:04 AM: Rohrabacher Ms. Siegel, what’s your educational background?
Siegel I got a degree in anthropology and and economics from Williams & Mary and I am an attorney.
Rohrabacher I believe Jim Hansen has received a significant amount of money from George Soros. Has anyone on the panel received money from Mr. Soros? There’s no question the earth is undergoing a warming trend. The major question is whether this is caused by human activity, and then wheter we can arrogantly think we can reverse what nature… and we’re looking at the effects of this on polar bears. I remembed the predictions of dire and doom for caribou. The caribou population has dramatically expanded since we built the pipeline. Quite often we hear people with these dire predictions to accomplish other political ends. We know the ice cores and these things give us an understanding of range in the planet. Timothy Ball stated that ice cores show that temperature leads increases in CO2. Dr. Juday was mentioning how methane gas was bubbling up as the temperature increases. Seems to me you’re backing up Dr. Ball’s observation.
Alley If I were to overpay and go into debt, I would also have to pay interest payments. We know that the historical variations in temperature are due to the earth’s orbit. The interest payments of CO2 must be included in our explanation of today’s observed warming.
Rohrabacher I must admit I don’t understand a thing you said.
Juday The only way to explain the trends. Something is dampening heat loss, not adding heat in the summer. Those are the characteristics of greenhouse gases.
11:14 AM Miller Dr. Hansen denies receiving money from Mr. Soros. He’s not here to defend himself, but we have a statement from him and we are entering it into the record.
Miller Do you know any scientists named Steve that don’t believe in global warming? How about scientists named Steve that do? [Two Steves that believe in global warming are mentioned.]
Juday We need to poke holes in the tundra and see if there’s charcoal in them. We’re seeing fires now; previous fires aren’t known to have existed, but we should check.
11:19 AM Rohrabacher I don’t have any scientists named Steve, but Patrick Michaels suggests that all the reports of melting ice on Greenland are exaggerated. Since Bill Clinton became President of the United States to get grants you had to say that global warming is caused by human beings.
This senior senior scientist says that polar bear populations are increasing.
Haseltine The 13 populations, in the reassessment we did, 5 are declining, 2 are depressed due to hunting, and none are increasing. I’m quoting from a study by Ian Serling, a senior polar bear scientist for Canada.
Rohrabacher It was a lot warmer in Greenland and I don’t know how many polar bears there were then. I’m not sure if that’s the natural number of polar bears in the world we should have now than what we have today. We have only one degree warmer, and we have five times less volcanic activity, which would tend to make it warmer, not to mention sunspots, which would imply natural causes, not an SUV, not to mention the warming going on Mars and Jupiter.
Juday I was the lead author in the Arctic climate assessment. I’d refer you to that if you’re interested in what happened when. You’ve brought up several different ideas and I’d offer to help you disentangle what happened and why.
Alley Scientists bubble with ideas and you help pay for activities to assess what makes sense and not. The National Academy of Sciences have looked at volcanoes, sunspots, etc., and have come to a high degree of scientific certainty that humans are responsible for the current warming. You quoted a scientist who claimed scientists modify their positions to get funding and personally, I’m under oath. And I would never ever ever do that. I am not lying to you.
11:30: Siegel If we take action on methane and black carbon we could start to see results by 2009.
Rohrabacher I’m surprised my staff hasn’t submitted that list yet. But here’s another respected scientist, William Grey suggests that so many people are invested in this, they’re scaring people to get more investment. How many polar bears were there 1000 years ago?
Haseltine We don’t know how many, but we know they existed then.
Rohrabacher We could assume there were fewer polar bears. What’s the natural number of polar bears?
Haseltine I don’t know if there’s a “natural” number, there’s the number the habitat can support.
Rohrabacher I think it’s wonderful seeing pictures of skinny polar bears, which then gives people the acceptance to regulate their lives the reality is 1000 years ago the polar bear population was totally different. What was the level of ice in Greenland 1000 years ago?
Alley I am one of the authors of a report that will be coming out. We’re in the temperature range we were 1000 years ago.
Rohrabacher It was dramatically warmer 1000 years ago and 8000 years go.
Juday No. We are probably warmer than we were 1000 years ago.
Miller I have one more question for Dr. Alley. You said the release of permafrost methane was a big hole in the IPCC modeling. Do you have a sense how big it could be?
Alley If we humans build all our fossil fuel, the methane feedbacks are on the order of 10-30%.
Juday If you burned up all of the readily accessible methane in the tundra it would double atmospheric CO2.
11:43 Miller Our hearing is now adjourned.