Marc Lefkowitz | 05/02/10 @ 9:00am
Invited guests of the Cleveland Museum of Natural History were given a brief but compelling presentation on Thursday morning, April 29, explaining the impact of global warming on the Arctic, and the consequences for the whole planet. The occasion was a tour by the Norwegian ambassador to the United States, together with climate science and policy experts, aimed at increasing the knowledge of key opinion leaders about the extent and effects of global warming in the northern regions of the globe.
There is dramatic evidence of significant warming in Arctic regions. In fact, the Arctic is warming much more quickly than other regions of the Earth. According to the presenters, this is what is expected as carbon dioxide levels in the atmosphere increase, and more of the sun's energy is trapped as heat. As the Arctic has warmed, snow and ice are melting. The Arctic ocean is now largely ice free in the summer, and ships can, for the first time during the summer, pass through the Arctic around Canada or Russia.
The cause of the rapid Arctic warming lies in a significant reduction in the area of the massive amounts of snow and ice that cover the polar regions. As greenhouse gas levels have gone up in the atmosphere, and the Arctic regions have begun to warm, the extent of snow and ice cover has been slowly decreasing for many years. Snow and ice are highly reflective, and have historically kept the frozen regions of the world from warming very rapidly. With a one degree centigrade rise in average temperature in the Arctic over the last century, the white layer covering water and land has been slowly but inexorably reduced. With each reduction , more dark ground or water is exposed, and more heat from the sun is absorbed during the Arctic summer. During the winter, land and water freeze again, but not so much, and so the next year there is more melting, and more dark surface area exposed.
Scientists refer to this as a positive feedback: as the Arctic warms more, the factors that cause additional warming become stronger and stronger. Now the Arctic ice cover is diminishing at a rate that substantially exceeds the previous expectations of scientists, and warming is accelerating at a surprising pace.
The melting of Arctic snow and ice is already having consequences. Permafrost is melting, leaving huge sinkholes in the ground and a damaged ecosystem. Huge storms are now battering and eroding coasts that were once protected by offshore ice. Sea levels are rising, as the warming ocean waters thermally expand, and as meltwater from glaciers and the Greenland ice pack flows into the sea.
Sea levels are now rising at a rate of 3.4 millimeters per year, and at current rates could be a foot higher by 2100. Ultimately, the Greenland ice sheet could cause a sea level rise of seven feet if it melts completely, and the Antarctic ice sheet could cause a 60 foot rise. Increases in sea level of this magnitude are not currently expected for several centuries; however, the processes of warming that have been set into motion, if not reversed, could ultimately make them inevitable.
Scientists are particularly concerned that the warming oceans and melting permafrost will release more carbon dioxide into the atmosphere, as biological materials that have been trapped in ice are thawed and begin to decompose. In addition, the warming Arctic is beginning to release significant amounts of methane gas. This methane release is especially troubling, since methane is more than twenty times as potent as carbon dioxide as a greenhouse gas.
The melting of the sea ice is also generating a kind of underwater "land rush," as the nations bordering the Arctic-notably the U.S., Canada, Russia, Denmark (by way of Greenland), and Norway-seek to stake mineral and fossil fuel claims to the continental shelf areas that may soon be permanently exposed to open water.
After the explanation of the causes and effects of Arctic warming, there was brief discussion of policy options for U.S. lawmakers on the greenhouse gas problem. The House of Representatives has already passed a "cap and trade' bill that would place a limit on greenhouse gas emissions, and increase the cost of carbon-based fuels. The Senate is just now beginning consideration of several possible proposals for cap and trade bills. The environment in the Senate is uncertain, since many other legislative issues, as well as the coming election in November, are crying for attention. The Senate also contains several members who have strongly denied the reality of global warming, and have claimed that a cap and trade bill will wreck the economy. President Obama and the Senate Majority leader have both come out strongly in favor of passing climate legislation this year. The next few weeks and months will tell if the Senate can overcome opposition and confront the reality of global warming.
The Arctic Forum presented convincing scientific evidence of the dramatic extent and effects of warming in Arctic regions. Given the strong worldwide patterns of atmospheric and oceanic circulation, this heat is inexorably spreading to the rest of the globe. The Arctic is clearly warning us that we are heading for a period of substantial worldwide warming, with dramatic and damaging effects: rising sea levels, increased ocean acidification, growing deserts, declining glacial water supplies, and large-scale extinction of vulnerable species. According to the strong consensus of scientists, concerted worldwide action to reduce greenhouse gas emissions is urgently needed to prevent the effects of warming from becoming irreversible, and catastrophic.
Many thanks to the Norwegian ambassador, Wegger Chr. Strommen, Dr. Steven Nerem of the Colorado Center for Astrodynamics Research, Dr. Pal Prestrud of the Center for International Climate and Environmental Research--Oslo (CICERO), and to Rafe Pomerance, Senior Fellow at Clean Air-Cool Planet, for a very informative presentation and discussion.
Thanks to Greg Studen for providing this report.