Sep 17 , 2012

As sea ice shrinks to record lows, Prof Peter Wadhams warns a 'global disaster' is now unfolding in northern latitudes

Forests may not help mitigate carbon dioxide pollution thanks to an uptick in CO2 emissions from decomposition

As higher levels of carbon dioxide permeate the Earth's atmosphere, scientists have long counted on forests -- which, as individual trees, grow larger in carbon-rich environments -- to soak up some of the excess.

But after nearly a decade and a half of observing forest ecosystems in controlled settings, scientists now see evidence that elevating carbon levels may cause forests to release as much extra carbon as they absorb.

Sea ice in the Arctic has melted faster this year than ever recorded before, according to the US government's National Snow and Ice Data Centre (NSIDC).

ASA says new satellite measurements indicate unprecedented recent Greenland ice sheet surface melt. The images above show the extent of surface melt over Greenland’s ice sheet over just a four day period - from July 8 (left) and July 12 (right). Measurements from three satellites showed that on July 8, about 40% of the ice sheet had undergone thawing at or near the surface. This melting dramatically accelerated to an estimated 97% of the ice sheet surface by July 12. On average in the summer, about half of the surface of Greenland's ice sheet naturally melts.