The world’s temperature has increased to levels not seen in at least 12,000 years, U.S. climate scientists report in today’s issue of “Proceedings of the National Academy of Sciences.” Rapid warming has occurred in the past 30 years, the researchers said, and there is little doubt that human activities are the primary factor.
Study coauthor James Hansen of NASA’s Goddard Institute for Space Studies said the new findings imply that the world is “getting close to dangerous levels” of manmade greenhouse gases.
The study concludes the Earth is now reaching and passing through the warmest levels in the current interglacial period, which has lasted nearly 12,000 years. This warming is also forcing a migration of plant and animal species toward the poles, the researchers said.
“But if further global warming reaches 2 or 3 degrees Celsius, we will likely see changes that make Earth a different planet than the one we know.” Hansen said.
European scientists recently reported dramatic openings over large areas of the Arctic’s perennial sea ice pack in August and a study released last week found Greenland’s ice sheet is melting far faster than scientists had previously thought.
Two other studies published this month by NASA scientists indicate that Arctic sea ice is melting at extraordinary rates.
Furthermore, British scientists reported this month that ice core records from Antarctica show the current levels of atmospheric carbon dioxide – the leading greenhouse gas – are higher now than at any time in the past 800,000 years and increasing at an unprecedented rate.
[Source: Environment News Service]