'Planetary Sunshade' could strip ozone layer by 76%
Planetary engineering projects to cool the planet could backfire quite spectacularly: a new model shows that a "sulphate sunshade" would punch huge holes through the ozone layer above the Arctic.
To make matters worse, it would also delay the full recovery of the Antarctic ozone hole by up to 70 years.
Pumping tiny sulphate particles into the atmosphere to create a sunshield that would keep the planet cool was first suggested as a solution to global warming by Edward Teller, a physicist was best known for his involvement in the development of the hydrogen bomb.
(image right of Dr. Teller, from Pickens School)
Simone Tilmes of the National Center for Atmospheric Research in Colorado, US, used computer models to see how a sulphate sunshade would affect the ozone layer, which protects us from harmful UV rays. She says it could have "a drastic impact".
(left image of Ms. Tilmes, from essl.ucar.edu)
In 2007, Ken Caldeira of the Carnegie Institution of Washington in the US found that if a sulphate sunshield were deployed and then removed – for instance because of a change in governments – the effects of global warming after the removal would be far worse than before the sunshield.
Caldeira has also found that a sunshade could cause severe drought.
(image right of Dr. Caldeira, from "Living On Earth")