Climatologist says global warming 'unequivocal'
15 Oct, 2008 By: Ron Hall LM Direct!You wouldn't describe climatologist Jonathan Overpeck's message to more than 1000 attendees at a luncheon at the first-ever WaterSmart Innovations ‘08 Conference in the ballroom of the South Point Hotel is Las Vegas as light entertainment. In fact, as the attendees sipped coffee and munched chocolate-covered strawberries and other dainty dessert treats Overpeck laid out a potential (and approaching) environmental crisis more alarming than the financial crisis now gripping the world.
Even so, Overpeck and his presentation were well received. As director of the Institute for Environment and Society at the University of Arizona, he was talking to a tuned-in audience consisting of water agency officials, elected officials, water/irrigation consultants and Green Industry professionals.
The theme to his half hour presentation was simple — “Global warming is unequivocal,” he stressed. “There's nothing political about it. The earth is warming.”
He admitted that computer models on future climate changes “don't get all the details right.” Even so, he said that about 20 different models from around the world predict anywhere from a 5.4 F. to 11 F. rise in earth temperatures by the year 2100 if greenhouse gas emissions are not curbed. This would cause sea levels to rise dramatically (goodbye coastal Louisiana and southern Florida) and would spread aridification and desertification in regions of the world that are presently green.
In general, dry regions of the world would get drier and wet regions wetter. But there's more to it than that. Global warming is accelerating fastest at regions of high altitude and in the artic.
“Everywhere around the world we're seeing a reduction in snow pack,” he said.
Since seven states in the U.S. Southwest depend upon the Colorado River, which depends upon the snow pack in the Rocky Mountains, for their irrigation and drinking water, this would have a profound impact on future water supplies, not only on cities such as Los Angeles, Phoenix and Las Vegas, but on agricultural, including California's huge vegetable production industry.
“The Colorado River flow is likely to decrease 10 to 40 percent by mid century,” Overpeck predicted..
Compounding the challenge, the population of Arizona is expected to double by 2030 and California is projecting 37% more people by the same date, he pointed out.
Overpeck said that he and many other scientists are convinced that rising levels of greenhouse gases caused by human activity are contributing to rising temperatures.
“There is no scientific debate about that anymore,” he said. “There is consensus here.”
Overpeck, who cited his two young daughters as reason enough for him to continue campaigning for reduced emissions of greenhouse gases, warned that the world must begin taking action now to head off the “most dangerous” consequences of global warming.
“These things need not happen,” he said, urging the audience to join the movement to reduce emissions to the atmosphere.
He said the United States must work toward generating carbon-free electricity and natural carbon sinks. He said it's not unreasonable to power all of America's electricity needs with wind and solar power, provided it can develop the necessary storage and transmission capabilities.
But even if emissions can be reduced significantly (admittedly a huge “if” in light of the industrialization of China and India), global warming will continue, although hopefully on the lower end of the scale.
“We'll have to adapt,” said Overpeck.
The Rain Bird Corp. sponsored Overpeck's appearance at the conference, which was put on by the Southern Nevada Water Authority
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