Twin-Pole Changes

Associated Press, October 1, 1998
Ice cores suggest global climate change 12,500 years ago

The Earth's climate abruptly warmed by 20 degrees or more to end an ice age 12,500 years ago, according to researchers whose findings may force a re-evaluation of the history of dramatic swings in the planet's climate. James White, a climatologist at the University of Colorado, Boulder, said that an analysis of new ice cores from the Antarctica show that the south polar area went through a rapid temperature increase at the same time that the north polar region was also warming. White, co-author of a study to be published Friday in the journal Science, said that the Antarctica ice cores show a temperature increase of about 20 degrees F within a very short time.

Ice cores from Greenland, near the Arctic, show that at the same time there was a temperature increase of almost 59 degrees in the north polar region within a 50-year period, White said. "What we see in Antarctica looks very, very similar to what we see in Greenland," said White. "We used to suspect that some of these big changes that occurred naturally in the past were only local. Since we see the same thing at opposite ends of the Earth, it does imply that the warming was a global phenomena." He said the findings "throw a monkey wrench into paleo-climate research and rearrange our thinking about climate change at that time."

White said researchers need to look more closely at how the Earth's climate slipped from an ice age that ended about 12,500 years ago and shifted into the current, more temperate climate. The findings, he said, also increases the urgency for researchers to understand climate shifts because it appears they could be abrupt and happen all over the Earth at the roughly the same time. "The challenge is to determine if a climate change will be a nice and gradual thing that we can adapt to or will it be a mode shift that happens suddenly," said White. The warming 12,500 years ago came within a typical human lifetime. Such rapid shifts in the climate on a global basis would make it very difficult for humans to adjust, he said. Climate affects agriculture, energy use, transportation and population shifts, and rapid changes would make adjustment in these things more difficult.