U. ILLINOIS (US)—Global temperatures of the last decade are higher than they have been in more than 2,000 years—and manmade emissions from heat-trapping gases are largely responsible, according to climate expert Donald Wuebbles.
“Climate does of course vary naturally, but the large changes we have been seeing in recent decades have the fingerprints of human emissions as being the primary driving force,” says Wuebbles, professor of atmospheric sciences at the University of Illinois. “The Earth clearly has a fever.”
Wuebbles—who prefers the term “global weirding” over “global warming”—has spent most of the past 40 years studying atmospheric chemistry and physical processes and their effect on climate, as well as the effects on the climate system resulting from human activities, including studies of the emissions that generate air pollution. He shares in the 2007 Nobel Peace Prize with his fellow members of the Intergovernmental Panel on Climate Change (IPCC).
Using supercomputers, Wuebbles creates and studies mathematical models that incorporate the complex physics, chemistry, and biology involved in the Earth’s climate system—the atmosphere, the oceans, the land surfaces, the ice—and the actions of humans.
The computer modeling helps study the effects of human and natural activities on atmospheric gases and particles, and on climate. Variables, such as emission levels, are altered to see what might happen to the climate system decades in the future.
The results show that over the next 90 years, warming of the planet’s land mass will increase substantially even if carbon dioxide emissions, which are known to be increasing, remain at present levels. The temperature of the oceans, which have a large heat capacity, also increases but at a slower rate.
Historical modeling also showed an increase in global climate temperatures corresponding with a rise in greenhouse gases.
Wuebbles was a member of a government task force that issued a report on climate science in June 2009, stating that “global warming is unequivocal and primarily human-induced.”
That report noted the U.S. average temperature is nearly 2 degrees Fahrenheit higher than 50 years ago, which is more than the global average increase. And 20 years from now that temperature will be up yet another degree.
If nothing is done to halt the rise, by the end of the century average temperatures across the country could be nearly 11.5 degrees Fahrenheit higher than they are now.
Wuebbles says one of his favorite ways to illustrate U.S. climate change is with maps of “migrating states.” In 40 years the temperature in Illinois will be more like today’s temps in Arkansas—by the end of the century Illinois will have the climate currently seen in central Texas, he predicts.
“The climate is changing, and the evidence clearly suggests it is largely being caused by human activities, ” he says.
“The good thing is, although we cannot totally reverse it, at least during this century, we can—by our energy and transportation choices—choose to keep the largest impacts from occurring.”
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