Stratospheric injections to counter global warming could damage ozone layer - The Diigo Meta page

• 10 May 08
  

  Danny Bradbury

  Crutzen's idea to seed the stratosphere with sulphur may not be such a great idea.

  geo-engineering Simone Tilmes eco-hacking Paul Crutzen

  • Sulfates from volcanoes provide a surface on which chlorine gases in the cold polar lower stratosphere can become activated and cause chemical reactions that intensify the destruction of ozone molecules, although the sulfates themselves do not directly destroy ozone.

  • The study found that injections of small particles, over the next 20 years, could reduce the ozone layer by 100 to 230 Dobson Units. This would represent a significant loss of ozone because the average thickness of the ozone layer in the Northern Hemisphere is 300 to 450 Dobson Units. (A Dobson Unit is equivalent to the number of ozone molecules that would create a layer 0.01 millimeters thick under conditions at Earth's surface).

     

  • In the Antarctic, most of the ozone is already depleted and the sulfate injections would not significantly reduce the thickness of the ozone layer. Instead, they would significantly delay the recovery of the ozone hole.

     
  • They also warn that a geoengineering project could lead to even more severe ozone loss if a major volcanic eruption took place at the same time.

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