To read today’s headlines you’d think Schwarzenegger just saved the world from global warming catastrophe a la the "The Day After Tomorrow." But why?

In a speech to the United Nations World Environment Day gathering in San Francisco, the gubernator proclaimed that the scientific debate on climate change is over and that the world needs to reduce greenhouse gas emissions. I suppose it’s encouraging that another prominent Republican has made such a declaration, in contrast to the willful ignorance of the White House. But isn’t this stuff common knowledge by now?

Schwarzenegger also unveiled a (non-binding) pledge to reduce California’s greenhouse gas emissions to 2000 levels by 2010 and to 1990 levels by 2020. By 2050, he aims to reduce emissions to 80 percent below 1990 levels.

Okay, that last bit is impressive. But 2050 is so far over the hazy edge of the political horizon that it doesn’t seem particularly courageous to make radical pledges for 45 years from now, when the near-term goals are actually fairly insubstantial.

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Plenty of other places in the US have made far more aggressive commitments to battling climate change.

New York, Massachusetts, and Maine have all pledged 10 percent reductions from 1990 levels by 2020, and New Jersey has agreed to 5 percent. And then there’s the recent US Mayor’s Climate Protection Agreement. To date, 156 mayors representing 32 million Americans have pledged to bring their city communities into Kyoto-compliance (7 percent below 1990 levels by 2012). All this makes California’s 0 percent below 1990 by 2020 look pretty wimpy by comparison.

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On the one hand, it’s encouraging that political and business leaders of all stripes are beginning to acknowledge the necessity of stopping global warming. On the other hand, it’s frustrating that their pledges are more milquetoast than manly. It’s a mystery to me how Arnold expects to see 80 percent reductions by 2050 when California intends to show no reductions from 1990 by 2020. Still, he boldly proclaimed: "As of today, California is going to be the leader in the fight against global warming."

I suppose he’s right. As long as you don’t count the northeast states; many of the big cities in the US; or Canada, Japan, New Zealand, Europe, and the other hundred-plus countries that ratified the Kyoto Protocol.