A study warns that the Earth's temperature is approaching a level not seen in a million years, implying that we are getting close to "dangerous" levels of human pollution.
The study finds that, while the world warmed slowly during the century to 1975, it has warmed at a more rapid rate of about 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade thereafter. The researchers say the global mean temperature is now within one degree Celsius (1.8 degrees Fahrenheit) of the maximum mean temperature of the past million years. Based on a 0.2-degree-Celsius increase per decade, that high point could be reached within 50 years.
The authors' conclusion: Further warming of one degree Celsius could suggest a critical level after which potential consequences -- such as higher sea levels and species extinction -- might be especially hard to manage.
"If further global warming reaches two or three degrees Celsius, we will likely see changes that make Earth a very different planet from the one we know," said James Hansen, lead author and head of the National Aeronautics and Space Administration's Goddard Institute for Space Studies in New York, in a prepared statement. "The last time it was that warm was in the middle Pliocene, about three million years ago, when sea levels were estimated to have been 25 meters (80 feet) higher than today."
Tuesday, September 26, 2006
It's Getting Warm In Here
In the Wall Street Journal this morning a report from James Hansen of NASA: