Background
The Arctic region plays an important role in the regulation of the Earth's climate. Conditions in the Arctic may suggest the existence of tipping points, including ice-albedo feedback from melting Arctic sea ice and Arctic methane release from melting permafrost and methane clathrate. The speed of future retreat of the Arctic sea ice is contentious. The IPCC Fourth Assessment Report of 2007 states that "in some projections, Arctic late-summer sea ice disappears almost entirely by the latter part of the 21st century." However, the ice has since undergone unexpectedly significant retreat, reaching a record low area in summer 2007 before recovering somewhat in 2008.
A 'tipping' process could potentially commence as the Arctic region warms, if there is positive feedback with sufficient gain. Professor Tim Lenton suggests that the retreat of sea ice is such a process, and the tipping may have started already. Geoengineering has been proposed for preventing or reversing tipping point events in the Arctic, in particular to halt the retreat of the sea ice.
Preventing such ice loss is important for climate control, as the Arctic Ice regulates global temperatures by virtue of its albedo, and also by restraining methane emissions from permafrost near the shoreline in the Arctic region. Additionally, the sea ice has a wider regional climatic role, and acts to maintain permafrost more generally in the region, by insulating the cold winter winds from the warm sea.
Read more about this topic: Arctic Geoengineering
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