How Earth-Scale Engineering Can Save the Planet
Maybe we can have our fossil fuels and burn ’em too. These scientists have come up with a plan to end global warming. One idea: A 600,000-square-mile space mirror
Article by Michael Behar featured in Popular Science Magazine
David Keith never expected to get a summons from the White House. But in September 2001, officials with the President’s Climate Change Technology Program invited him and more than two dozen other scientists to participate in a roundtable discussion called “Response Options to Rapid or Severe Climate Change.”
While administration officials were insisting in public that there was no firm proof that the planet was warming, they were quietly exploring potential ways to turn down the heat.
Most of the world’s industrialized nations had already vowed to combat global warming by reining in their emissions of carbon dioxide, the chief “greenhouse gas” blamed for trapping heat in Earth’s atmosphere. But in March 2001 President George W. Bush had withdrawn U.S. support for the Kyoto Protocol, the international treaty mandating limits on CO2 emissions, and asked his administration to begin studying other options.
“If they had broadcast that meeting live to people in Europe, there would have been riots”
Keith, a physicist and economist in the chemical and petroleum engineering department at the University of Calgary, had for more than a decade been investigating strategies to curtail global warming. He and the other scientists at the meeting—including physicists from Lawrence Livermore National Laboratory who had spent a chunk of their careers designing nuclear weapons—had come up with some ideas for “geoengineering” Earth’s climate. What they proposed was tinkering on a global scale. “We already are inadvertently changing the climate, so why not advertently try to counterbalance it?” asks retired Lawrence Livermore physicist Michael MacCracken, a former senior scientist at the U.S. Global Change Research Program who helped organize the meeting.
“If they had broadcast that meeting live to people in Europe, there would have been riots,” Keith says. “Here were the bomb guys from Livermore talking about stuff that strikes most greens as being completely wrong and off-the-wall.” But today, a growing number of physicists, oceanographers and climatologists around the world are seriously considering technologies for the deliberate manipulation of Earth’s climate. Some advocate planetary air-conditioning devices such as orbiting space mirrors that deflect sunlight away from Earth, or ships that intensify cloud cover to block the sun’s rays. Others are suggesting that we capture carbon dioxide—from the air, from cars and power plants—and stash it underground or react it with chemicals that turn it to stone.
Carbon dioxide wasn’t always public enemy number one. For the past 400,000 years, the concentration of CO2 in the atmosphere has fluctuated between about 180 and 280 ppm (parts per million, the number of CO2 molecules per million molecules of air). But in the late 1800s, when humans set about burning fossil fuels in earnest, atmospheric CO2 began to increase with alarming speed—from about 280 ppm to the current level of almost 380 ppm, in a scant 100 years. Experts predict that CO2 could climb as high as 500 ppm by 2050 and possibly twice that by the end of the century.
As CO2 levels continue to rise, the planet will get hotter. “The question now,” says Ken Caldeira, an atmospheric scientist at Lawrence Livermore and one of the world’s leading authorities on climate change, “is what can we actually do about it?” Here are some of the geoengineering schemes under consideration. Continue reading
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Source Popular Science. Aviation and Space. Article by Michael Behar August 2005
Professor David Keith - Canada Research Chair in Energy and the Environment; Professor Department of Chemical and Petroleum Engineering and Department of Economics, University of Calgary. Adjunct Professor Department of Engineering and Public Policy Carnegie Mellon.
Prof. Keith's web page | Return to beginning of article
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