Fossil fuel use will lead to 'climate storm'

Adelaide Advertiser
Thursday 5/3/2009 Page: 19

UNTIL now, most discussion of climate change has been about what scientific evidence shows is likely to happen between now and 2100. However, scientific research shows that the carbon dioxide gas released from burning fossil fuels lasts in the atmosphere much longer than mere decades. David Archer, a leading climate researcher who teaches at the University of Chicago, has written a new book that looks at carbon dioxide's "long tail" and what it means for changes on Earth in the future.

If the world continues its heavy use of coal over the next couple of hundred years until it is essentially used up, it will take several centuries more for the oceans to absorb about three-quarters of the carbon dioxide emitted into the atmosphere. In those centuries, there would be a "climate storm" that Archer says would be significantly worse than the climate forecast from now to 2100.

The remaining carbon dioxide - the long tail - would stay in the atmosphere for thousands of years, leaving a warmer climate. About 10% of it would still be in the atmosphere in 100,000 years, Mr Archer writes in The Long Thaw. How Humans Are Changing the Next 100,000 Years of Earth's Climate. "Ultimately, the amount of fossil fuel available could be enough to raise the atmospheric CO2, concentration higher than it has been in millions of years," Mr Archer writes.

Because of the long life of CO2, from fossil fuels, the climate impacts would last for many thousands of years. Ice sheets would melt, raising seas high enough to swamp 10% or more of the world's agricultural land.

Other climate impacts could include uncomfortable heat and drier continental interiors, Mr Archer writes. "In the long run, it could be a steep price to pay for a century or so of fossil fuel energy." Mr Archer studies the carbon cycle of Earth as it interacts with global climate. His slim book is a clear explanation of carbon dioxide and climate change for non-scientists. It also explains how the climate changed in the distant past and looks ahead to the deep future.

His work has been a part of what John Holdren, whom President Barack Obama named as his science adviser, has called the "tremendous effort" among scientists to reach a "centre of gravity" in the understanding of climate change. The results of this work are available in the reports of the U.S. National Academy of Sciences and the UN's Intergovernmental Panel on Climate Change.

The conclusion, as Mr Holdren summed up at his confirmation hearing recently: "Climate change is real, it's accelerating, it is caused in substantial part by human activity, it is dangerous and it is getting more so." Like Mr Holdren and other climate experts, Mr Archer concludes that there's still time to cut fossil fuel emissions enough to avoid disaster.

"The question may come down to ethics, rather than economics," he writes, much as the issue of slavery did more than a century ago. "Ultimately it didn't matter whether it was economically beneficial or costly to give up. It was simply wrong."