So how much should we worry about this right now? I mean, assuming that worrying would actually do us some good, rather than just raise our bad cholesterol and drive us to drink?

The die-off of most of the phytoplankton would be a huge catastrophe. However, here are some reasons that we shouldn't succumb to outright panic quite yet:

1. It's one paper. I am not casting aspersions on the authors or their methodology, but the whole idea of science is that even the smartest people can be wrong. As with other attempts to reconstruct past climate, they're using a series of proxies for past events that have much weaker accuracy than the direct measurements we're now using. That doesn't mean they're wrong, but it does leave them more open to interpretation.

2. All the carbon we're burning used to be in the atmosphere. Yet the planet supported life. Indeed, the oil we're burning comes from the compressed, decayed bodies of . . . phytoplankton. This suggests that some number of phytoplankton should be able to survive high concentrations of the stuff.

3. There are positive feedback effects, but also negative ones. One of the things that drives me batty about environmentalists and journalists writing about climate change is the insistence that every single side effect will be negative. This is not really very likely, unless you think that every place on earth just happens to be at the very awesomest climate equilibrium possible as of 9:17 am this morning, or that global warming is some sort of malevolent god capable only of destruction.



Mind you, this is not an argument for letting it happen; I'm not a fan of tampering with large, complex systems that I don't really understand, which is why I tend not to support much direct government intervention in the economy--and why I do, nonetheless, support a hefty carbon tax.

But there's a certain tendency to ignore mitigating offsets, such as the fact that higher carbon concentrations make terrestrial plants grow more lushly, sucking up some of that extra carbon dioxide in the atmosphere. At least, as long as we don't turn them into biofuels, that is. There's also a tendency to ignore mitigation rather than reduction, on the grounds that emissions reduction is "easier". Well, I suppose it is easier if you assume away the political problems. But no matter how hard I assume, I keep waking up in a world where we've made no meaningful progress on emissions reductions. At this point, I've got more faith in America's engineering talent than in her ability to conquer fierce political resistance to reductions at home and abroad.

