Despite this winter’s record-breaking cold, global warming theorists insist that in the long run, the planet is still heating up.
In fact, while the eastern two-thirds of the United States and much of Europe had a colder-than-normal winter, average temperatures worldwide were seven tenths of a degree Fahrenheit above normal during the last three months, according to James E. Hansen, the scientist who brought world attention to the idea that the Earth is getting warmer.
Hansen, director of NASA’s Goddard Institute for Space Studies in New York, says one chilly season hasn’t disproved the global warming theory or forced him to shy away from his prediction that by the end of the next century, average temperatures will be about 5 degrees Fahrenheit warmer than they are today.
Those who have battled the recent cold may find it hard to believe that there is, in fact, a warming trend.
In Mt. Pleasant, Iowa, the mercury fell to 27 below on Feb. 3, the most frigid it had been there since 1905, according to National Weather Service records. In Florence, S.C., the temperature fell to a frosty 11 degrees, the chilliest since 1958. And in Tower, Minn., the air registered minus 60 degrees, the coldest since 1899.
Hansen says he’s not sure if most people are “willing to remember the last time it was really hot.” Instead, people tend to think “that if it’s cold, then it’s getting colder,” he said Friday.
But weather information collected around the world during December, January and February show the mean global temperature to be 59.7 degrees Fahrenheit, compared with a mean global temperature of 59 degrees for those months from 1950 to 1980.
Scientists agree that average temperatures on the planet have gone up nine tenths of a degree Fahrenheit over the last 100 years. The warming results from a buildup of greenhouse gases - carbon dioxide, methane, nitrous oxide and chlorofluorocarbons that come from the burning of fossil fuels - that trap heat near the Earth.
But climatologists continue a bitter debate about how direct a role human activity has played in the warming, how much warmer the planet will become, and what effects, like rising seas and long droughts, might follow.
The most dire forecasts say rising mercury on Earth could bring about both devastating floods and droughts. The shift could expand the parts of the world where malaria and yellow fever are found.
And more extreme weather - from hotter summers to more violent rain storms - could even bring on psychological disorders and increase property insurance premiums, some scientist warn.