Reversing trends

For those wondering whether there's any merit to trying to fight global warming when it's already gone this far, the example of the ozone layer should remind us that concerted action can help to reverse environmental decline:

The hole in the ozone layer this year will probably be slightly smaller than the all-time largest of 2003, in line with the general trend of a gradual healing of the ozone layer's depletion, a UN agency said Friday...

Mr. Braathen said agencies such as his must continue to closely monitor the ozone layer via satellites and ground stations. Signatories to the anti-CFC treaty known as the Montreal Protocol, particularly developing countries that had looser phase-out schedules, should respect the accord, he stressed.

More than 180 countries have signed the Montreal Protocol, which took effect in 1997.

Based on this example, it's clear that nobody can expect instant results: for a few years after the Montreal Protocol was signed, the cumulative impact of previous CFC use still made the hole worse than it had been before. But once a determined global effort takes hold, we can see quantifiable positive results.

It's already happening with regard to the ozone layer, despite the negative impact that global warming itself may have on the ability of the layer to repair itself. The next step is to get the world's largest economies to agree to recognize global warming as an equally important priority. With enough cooperation, we may yet be able to point to similar results on global warming within the next decade.