Wednesday, October 22, 2008

Rising Temperature in Arctic

Autumn temperatures in the Arctic are at record levels, the Arctic Ocean is getting warmer and less salty as sea ice melts, and reindeer herds appear to be declining, says the Time Magazine.According to Jackie Richter-Menge of the Cold Regions Research and Engineering Laboratory in Hanover, N.H, the planet is interconnected so what happens in Arctic does matter.

The region has long been expected to be among the first areas to show impacts from global warming, which the Intergovernmental Panel on Climate Change says is largely a result of human activities adding carbon dioxide and other gases to the atmosphere.

The report noted that 2007 was the warmest year on record the Arctic, leading to a record loss of sea ice. This year's sea ice melt was second only to 2007.

Rising temperatures help melt the ice, which in turn allows more solar heating of the ocean. That warming of the air and ocean affects land and marine life, and reduces the amount of winter sea ice that lasts into the following summer.

The study also noted a warming trend on Arctic land and increase in greenness as shrubs move north into areas that were formerly permafrost.

While the warming continues, the rate in this century is less than in the 1990s due to natural variability, the researchers said.

In addition to global warming there are natural cycles of warming and cooling, and a warm cycle in the 1990s added to the temperature rise. Now with a cooler cycles in some areas the rise in temperatures has slowed, but Overland said he expects that it will speed up again when the next natural warming cycle comes around.

Asked if an increase in radiation from the sun was having an effect on the Earth's climate, Jason Box of the Byrd Polar Research Center in Columbus, Ohio, said while it's important, increased solar output only accounts for about 10 percent of global warming.