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Skating on Thin Ice

Dan Lashof

Posted September 6, 2007 in Solving Global Warming

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One of the most dramatic and visual manifestations of global warming is the declining expanse of arctic sea ice. The data coming out of the Arctic now are shocking even to those of us who read bad news about global warming for a living. Scientists at the National Snow and Ice Data Center are now tracking Arctic sea ice expanse in real time and a new record low is being set just about every day. As of September 4, 2007 Arctic sea ice extent was 4.42 million square kilometers (1.70 million square miles), almost 20 percent lower than the record low set on September 20-21 2005. September typically has the lowest monthly average sea ice extent, but August 2007 has already set the record for the lowest monthly average ever recorded by satellite for any month—a startling 31% below the average for all Augusts since 1979. We can expect new record daily lows through at least the middle of September and a new record monthly low when the full month’s data come in.

Map of this year's steep decline in extent of Arctic sea ice.

Climate models predicted abrupt and widespread sea ice melting early in the 21st century, beginning as soon as 2015, but it seems that the real world continues to outpace even worse case scenarios. Arctic sea ice is already floating so melting it does not add to sea level, but it does accelerate global warming because sea ice is better at reflecting back the sun’s rays than is open water, which absorbs more solar heat. Melting glaciers, on the other hand, do add to sea level and they are also melting faster than expected according to Mark Meier of the University of Colorado and colleagues who reported their findings in the August 24th issue of Science.

You can read more about these and other recent scientific findings in the Science Update I recently compiled for distribution to Congressional offices. Its not a pretty picture, but if pictures are worth a thousand words maybe the image of the shrinking ice cap will help compel Congress to act.

 

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Comments

Gregory Markowski, Ph.D.Sep 14 2007 07:15 PM

To whom it will concern,
The best bills in Congress miss two crucial facts, the 1st scientific, the 2nd economic and motivational: (1) The greenhouse gases (GHG) we emit in the near future will have the most effect on global warming; (2) Large reductions can be done quickly and their cost is little to a net savings (in other words, a profitable investment in monetary terms alone).
(1) Any emissions in the near future will have a nearly immediate effect given the large rapid climate changes that are already taking place. Their effect is highly likely to be difficult and costly to reverse, if practical at all. This is what is meant by being close to the "tipping point". We do not need scientific certainty to take our situation extremely seriously--that is a fool's argument, all we need is be reasonably sure that the risk is dramatically larger than we thought. The latter should be clear to anyone who follows the current climate surprises, such as the Arctic sea ice which is disappearing far more rapidly than most scientists predicted (except Hansen, if my memory is correct, this author [who was much easier to muffle], and Al Gore before he became a VP).
(2) A large amount of energy can be saved by conservation (e.g., substituting compact fluorescents) quickly (5 years or less) and at a net saving. (Simply repairing vehicles or buying substantially higher milage vehicles gives near major savings. Inflating tires to near maximum pressure, not just manufacturer's recommended pressure (usually that a very soft ride), will typically give 3 to 5% fuel savings.) Small, inexpensive, wind generators are now on the market which can substantially reduce fossil fuel use for electricity at the household level (not to mention solar water heating). There are at least 2 dozen things a household or a business can do, that when added up, will give a surprisingly large overall GHG reduction at little overall cost. In addition, several important changes can be implemented within 8 years, one of the more significant overlooked ones is largely eliminating soot emissions (e.g., from diesels), another, a rapid increase in commercial wind turbine use--and wind farm have a time line of about 5 years, or possibly less. Also, there are both longer term and temporary stop-gap measures which can be used to increase reflected sunlight, thus, counteracting GHG emissions directly.
The first 40-50% reduction for the US and Canada is rather quick and easy and crucial, it is the next 30-40% that will take 2 to 3 decades (but not 4 1/2) and require long-term planning and commitment. (And will be very expensive, and probably minimally successful, if done by Crony, i.e., corrupt, Capitalists.)

[Ph.D., Atmospheric Sciences, Listed: Who's Who American Men and Women of Science, B.S., with Honor, Physics, California Institute of Technology]

Paul NesmanSep 25 2007 03:29 PM

I am concerned about global warming. It is happening. It is a fact. There are measurements and charts and graphs from professionals dedicated to the study thereof. Yet we all know that the earth has warmed and cooled many times over the last billion years. Why is this any different? Where are the charts that compare the last warming to this one? Why do we get pages and documentaries of green-speak and yet they always fail to discuss the last rise and fall of the mercury?
I want to be convinced. My mind is open. However, I have not been convinced that our existance has had any more of an influence on the natural cycle than a tiny nudge.
Show me the numbers. Please!

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Switchboard is the staff blog of the Natural Resources Defense Council, the nation’s most effective environmental group. For more about our work, including in-depth policy documents, action alerts and ways you can contribute, visit NRDC.org.

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