Columbus (Ohio) Dispatch
February 17, 2006


By Mike Lafferty

ST. LOUIS -- Humans are burning fossil fuels so rapidly that Earth is headed toward its warmest period in 55 million years, a panel of scientists warned yesterday.

If that sounds bad, James Zachos, a researcher from the University of California, Santa Cruz, would agree.

"It's a threat to life as we know it," said Zachos, who joined a panel of researchers discussing global climate change at the annual American Association for the Advancement of Science meeting.

Scientists, analyzing ocean sediments, have identified global warming periods 55 million, 93 million and 120 million years ago. These periods, they say, probably were sparked by carbon dioxide from increases in volcanic activity.

Burning coal, oil and naturalgas reserves at the current rate is expected to release 5,000 gigatons of carbon dioxide -- a gigaton is 1 billion tons -- into the atmosphere and push carbondioxide levels to more than five times current levels.

The last time the atmosphere was laced with that much carbon dioxide the world's oceans stagnated with dead vegetation and life in the sea and on land was fundamentally altered, the researchers say.

"That's exactly the amount we will add to the atmosphere if all fossil fuels are combusted," Zachos said.

While it might take a century or more to release that much carbon into the air, Mother Nature might require 100,000 years or more to regain the balance, the panel said.

Even scarier, according to Matt Chandler, a climate modeler from Columbia University, is that we might be underestimating the effects. Humans already could be approaching a threshold that would trigger changes no matter what is done to limit carbon-dioxide releases.

Estimates are that a temperature increase of 3 to 5 degrees Fahrenheit would boost ocean levels by at least 45 feet, flooding the East Coast, Florida, the Gulf Coast and other low-lying areas.

That temperature boost would be only about half what the atmosphere warmed during past global events.

Scott Wing, a paleobotanist at the Smithsonian Museum of Natural History, called global warming the biggest threat to humanity.

People have a difficult time coming to grips with it, he said.

"A crisis that is unfolding over a few centuries doesn't seem like a crisis, but it is," he said.

Copyright 2006, The Columbus Dispatch