Friday, October 01, 2010

Andrew Freedman at Climate [Hoax] Central thinks you don't have access to the Internet

As Arctic Sea Ice Melt Season Ends, Sharp Downward Trend Continues | Reuters
After a false alarm earlier this month, the 2010 Arctic sea ice melt season has come to a close, with sea ice extent reaching the third-lowest in the satellite record. This continues the steady and steep decline in sea ice cover during the past few decades, which scientists have traced mainly to emissions of greenhouse gases, as well as natural climate variability. Underscoring the rapid changes sweeping the Arctic, both the Northwest and Northeast Passages were open for a time, and two sailboats set new records for transiting both of them in just one season — a feat that would have been impossible throughout modern history.
...
Another key metric—sea ice volume—tells a similar, albeit more alarming story (for information on the differences between sea ice volume and extent, see NSIDC's FAQ page). According to the University of Washington's Polar Science Center, sea ice volume plunged to a new record low this year. The chart of sea ice volume shows a stunning drop compared to the overall rate of decline in the past several decades, and indicates that this summer, the Arctic Ocean contained unusually sparse and thin sea ice.
...
Sea ice decline will be very difficult to reverse—even if greenhouse gas emissions are rapidly and significantly cut, a scenario that appears increasingly unlikely—since feedback effects help ensure that sea ice loss in the summer leads to warmer water and air temperatures and thinner ice in the fall and winter, which leaves more vulnerable ice heading into the next melt season. The realclimate blog has an excellent post on climate feedbacks that explains the ice-albedo feedback, which is one of the key ways in which a warming climate may propel a virtually self-sustaining loss of sea ice.

Some climate change contrarians, such as meteorologist Anthony Watts, instead promote the idea that sea ice decline (along with the majority of recent warming in general) is primarily driven by natural ocean cycles, and that a cooler North Atlantic and Pacific Ocean could allow Arctic sea ice to recover. I find that argument to be highly dubious, based on a reading of the scientific literature and interviews with Arctic sea ice researchers.
Ice Expanding And Thickening Over The Last Week | Real Science
The ice is older, thicker, more concentrated – and growing faster. That is what an objective person would call a “recovery.”

No comments: