Capturing Climate Change – IEEE Spectrum

Even without a ratified international agreement, many countries have begun, or at least are beginning to plan, cuts in greenhouse gas emissions. China, driven by urban air pollution, is cutting coal use. The European Union, based in Brussels, Belgium, is establishing policies for achieving the cuts called for by Kyoto. In one action, the Union has drafted a law establishing emissions trading between companies, a policy seen as a critical tool for enabling countries to meet Kyoto targets. So far, the United States has promised nothing, though its actions could impact the problem if, for example, sport utility vehicles were mandated to meet the gasoline efficiency standards of ordinary vehicles, or computer-controlled heat-management systems were installed in more buildings.

Cutting emissions isn’t the only answer. Scientists are also working the other half of the equation: increasing the amount of carbon dioxide absorbed on earth. Plants perform this task, growing faster when there is more carbon dioxide in the air. Oceans absorb it, slowly taking it in until they store two orders of magnitude more than the atmosphere. Various schemes have been suggested to increase storage, like feeding iron into the oceans, so that algae that absorb carbon dioxide proliferate.

Or one could simply do nothing to stop global warming. “On a pessimistic day,” said Schimel, “it’s not hard to imagine that we’ll just take the easy way out, use fossil fuel indiscriminately, and buy a lot of air conditioning. That scenario leads you to carbon dioxide levels of a thousand parts per million and global mean temperatures up many degrees from today.”

The good news is that on most days scientists are cautiously optimistic. Said NCAR’s Trenberth: “Maybe we can’t make the problem go away, but we can certainly make scientific advances, we can slow down the rate of warming, and we can gain enough time to allow us to adapt.”