Monday, February 08, 2010, 12:00PM - 1:00PM
National Snow and Ice Data Center (NSIDC)
Nowhere on the planet are emerging signals of climate change more visible than in the Arctic. There is increasing recognition that these changes will have impacts extending well beyond the Arctic region itself. This includes responses of atmospheric circulation patterns to reduced ice extent, and release of carbon dioxide and methane to the atmosphere as terrestrial and sub sea permafrost warms and thaws. As sea ice retreats, the Arctic also becomes more accessible to shipping and extraction of oil and natural gas reserves under the Arctic coastal seas. Projections of how Arctic conditions will evolve through the 21st century, which in turn bear on the wider impacts of Arctic change, are fraught with uncertainty. Simulations with the current generation of coupled global climate models with the A1B emissions scenario project that the Arctic Ocean will become essentially ice free in late summer as early as 2030 to as late as 2100 and beyond. While a growing number of studies modeling studies indicate that loss of the ice cover will have significant impacts on atmospheric circulation beyond the Arctic, there is no consensus regarding even the basic structure of expected changes. Projected when and to what degree the Arctic becomes a net carbon source to the atmosphere is confounded by, among other things, the large range in projected warming rates, which in turn reflects the strength of Arctic feedbacks linked to changes in snow and sea ice cover.