NCPA - National Center for Policy Analysis


June 25, 2007

Not all climate scientists are working on plans to reduce global warming.  Some are figuring out ways to deflect it, says Robert Lee Holtz in the Wall Street Journal.

Among the plans:

  • Tom Wigley at the National Center for Atmospheric Research and Paul Crutzen at the Max Planck Institute have proposed cooling the planet by an artificial haze of sulfur particles, which would reflect solar radiation.
  • Indeed, The 1991 eruption of Mt. Pinatubo spewed enough sulfates to lower the average world temperature by almost one degree Fahrenheit for a year, with no apparent ill effects.
  • University of Arizona astronomer Roger Angel has put forward a plan to cool Earth by orbiting 16 trillion tiny mirrors.

Further, researchers at the Carnegie Institution calculated the effects of curbing solar radiation instead of CO2 emissions over the next 75 years.  Their results:

  • Engineering efforts to block sunlight could reverse global warming -- at least temporarily.
  • Of 11 different sunshade scenarios tested in a complex computer simulation of the world's climate in every case, the planet quickly cooled, often in as little time as five years.
  • They didn't weigh the merits of any particular engineering plan but instead evaluated the broad effects of lowering solar radiation as a counterweight to rising carbon-dioxide emissions.

The plans vary in cost; the sulfur sunshade comes in at $400 million a year, the mirrors in the trillions of dollars.  But many geo-engineering advocates are desperate for a safety net, worried that people can't cut greenhouse gas emissions quickly enough to make a difference. "I don't think we can globally reduce emissions enough," says Wigley. "Forget the politics; I don't think we can do it technologically."

Source: Robert Lee Holtz, "In Case We Can't Give Up the Cars -- Try 16 Trillion Mirrors," Wall Street Journal, June 22, 2007.


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