Prepare for a bit of cooling predicts geologist
By Dennis T. Avery
"Global warming is over—at least for a few decades," geologist Don Easterbrook, professor emeritus from Western Washington University told the Heartland Institute's Fourth International Conference on Climate Change on May 19. He warned, however, us not to rejoice. Colder winters kill twice as many people as hot weather while crop production suffers from shorter growing seasons and weather-disrupted harvests.
Dan Miller, climate expert with the Roda Group and ardent believer in Anthropogenic Global Warming, responded to Easterbrook at Fox News: "It's absurd to talk about global cooling when global heating is with us and accelerating." But Miller is referring to the current temperature spike from an El Nino in the Pacific Ocean—a short-term climate event already ending, according to Pacific sea surface temperatures. The key question now is where the temperatures will go after the El Nino fades.
Easterbrook offered geological evidence that the earth has had ten big "recent" warmings that dwarf the 0.7 degree temperature increase estimated for the 20th century. Over the past 15,000 years, those temperature shifts drove the earth's temperatures radically up or down by 9–15 degrees C within a single century. He also noted 60 sharp-but-smaller temperature changes in the past 5,000 years. All of these occurred before 1945, when the post-war Industrial Boom began to ramp up human-emitted CO2 levels.
Easterbrook calls this evidence "astonishing." Current data seem to support Easterbrook's prediction of an end to global warming, at least for the next three decades. Since 1998, atmospheric CO2 has continued to increase—but total solar activity, as measured by satellites, has declined sharply after trending strongly, but erratically, upward for 150 years.
Satellite-measured solar activity has also been trending down moderately, which essentially predicts cooling. And the Pacific Decadal Oscillation has shifted into its cool phase, as NASA told us in 2008. Tree rings and coral samples tell us these PDO shifts have predicted moderate cooling for the whole earth, lasting for about 30 years at a stretch. Easterbrook predicts that this PDO phase will last until 2030, with warming from 2030–2060, and then cooling again to 2090.
The PDO, however, doesn't seem to control whether the planet as a whole will warm or cool over the next century. Easterbrook's geology says powerful, natural cycles, probably solar-driven, control longer-term climate trends. Ice cores, seashells, and fossil pollen all show a moderate-but-abrupt 1,500-year cycle, which apparently gave us the Little Ice Age and Medieval Warming, the Roman Warming, and 500 similar previous warmings over the past million years.
The prediction: Higher temperatures will not parboil the earth. Global warming will continue, slowly and erratically, perhaps with another 0.5 degree C over several hundred years. The biggest danger will be extended drought in unusual regions, almost certainly including Kenya and California. Such drought ended the Mayan civilization in the 9th century. But it's as unstoppable as the sun itself. This very real threat should be the focus of modern technology in helping effected areas to adapt.
Eventually, we'll get another big Ice Age, and our descendents will deride the memory of Al Gore's "inconvenient truth"—as they shiver watching glaciers approach Chicago.
Dennis T. Avery, a senior fellow for the Hudson Institute in Washington, DC, is an environmental economist. He was formerly a senior analyst for the Department of State. He is co-author, with S. Fred Singer, of Unstoppable Global Warming Every 1500 Hundred Years, Readers may write him at PO Box 202, Churchville, VA 24421 or email to email@example.com
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