More evidence humans are ginning climate

Antarctic researchers have found convincing evidence that, until human activity began to massively ramp up carbon dioxide levels in the atmosphere, that our biosphere could regulate itself.

The average change in the amount of atmospheric carbon dioxide over the last 600,000 years has been just 22 parts per million by volume, Richard Zeebe said, which means that 22 molecules of carbon dioxide were added to, or removed from, every million molecules of air.

Since the Industrial Revolution began in the 18th century, ushering in the widespread human use of fossil fuels, the amount of carbon dioxide in the atmosphere has risen by 100 parts per million.

That means human activities are putting carbon dioxide into the atmosphere about 14,000 times as fast as natural processes do, Zeebe said.

And it appears to be speeding up: the U.S. government reported last week that in 2007 alone, atmospheric carbon dioxide increased by 2.4 parts per million.

The natural mechanism will eventually absorb the excess carbon dioxide, Zeebe said, but not for hundreds of thousands of years.

Climate change skeptics and outright global warming denialists have claimed that the climate will take care of itself as it has in the past. But, a rate 14,000 times as fast as natural processes tends to refute that.