A funny thing seems to be happening on the way to global warming: The instrument of our destruction is fading away. Several million tons of carbon dioxide, a major greenhouse gas that is supposedly on the increase, have gone missing for the last two decades.
Less than half of the carbon dioxide that fossil fuels annually belch into the atmosphere remains there. Oceans absorb roughly a third, and the rest apparently just disappears from the ether. According to a study by a team of seven scientists in the October 19 Science, a North American "carbon sink" consisting of the continent's forests and plants may be absorbing up to a quarter of the carbon. That's more than the entire fossil-fuel-produced carbon output of the United States and Canada combined.
So North America may actually be contributing to a net reduction in atmospheric carbon. And if the carbon is absorbed by growing forests and formerly fallow farmland, it means that industrial activity is causing the continent to get greener, not warmer.
Global warming believers have been quick to challenge the findings. Some point out that such a large reduction is hard to square with another apparent sink in South America. Others question the stability of the researchers' models.
Some are more worried about the political implications. "We are all concerned that people will find it convenient to accept the result," ecologist David Schimel of the National Center for Atmospheric Research told Science. He frets that such findings argue against U.S. compliance with the latest global warming treaty, which calls for reductions in carbon emissions.
He's right. The findings may well breathe fresh air into global warming debates in the Senate, which has yet to ratify the treaty.