Thursday, March 8, 2007

Fixing the ozone layer also slowed global warming

From the pages of Science: The Montreal Protocol, designed to save the ozone layer from the harmful effects of CFC's, has had the unexpected benefit of preventing billions of tons of greenhouse gases entering the atmosphere.
Dodging a Warming Bullet

What's good for the ozone layer has been even better for Earth's climate. According to a new study, a 20-year-old ban on ozone-depleting chemicals has been extremely effective at curbing greenhouse gases as well. In fact, it has already had more impact than a fully implemented Kyoto Protocol would have accomplished, even though the protocol was specifically designed to target atmospheric warming. The findings, say the authors, emphasize the importance of ridding the planet of these powerful greenhouse substances.

Policymakers, however, initially targeted these compounds not for their role in global warming but rather for their damage to the ozone layer

The rise in atmospheric concentrations of CFCs has been arrested, and the ozone layer has begun to show signs of recovery, to the point where scientists predict it will heal completely sometime after 2050.

Velders and colleagues calculate that since 1987, gradually shutting down CFC emissions has removed the equivalent of about 11 billion metric tons of carbon dioxide from the atmosphere. By comparison, even if the Kyoto Protocol had been fully ratified it would have removed only about 2 billion tons of carbon dioxide thus far.
It's pretty well agreed that by pumping increasing amounts of greenhouse gases into the atmosphere, we're forcing rapid climate change. We likely don't know all the secondary effects that's causing. Solving one crisis helps solve the others. Instead of getting used to it, we need to act to stop it.

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