Cap and trade, if it passes at all, will be an imperfect and politically compromised attempt to slow the growth of carbon emissions. It might be "the most important piece of environmental legislation" in all of spacetime, but it will hardly put a dent in worldwide emissions if China and India and other large countries don't take measures to control their own carbon output.
According to Edward L. Glaesar, a Harvard economics professor, that's precisely why passing a climate change bill is so essential. It's not about the policy. It's about sending a message.
If per capita carbon emissions in both China and India rise to United States per capita levels, then global carbon emissions will rise 138 percent. If the emissions of these rising superpowers stop at French, rather than American, levels, global emissions will only increase by about 28 percent.
This suggests the biggest contribution that the United States can make to reducing world carbon emissions is to persuade the Indians and Chinese to use energy like Frenchmen rather than Americans.
But today there is a powerful whiff of hypocrisy that surrounds Americans who try to persuade the Chinese to use less energy. In the words of one distinguished economist, it is like "a nation of S.U.V. drivers trying to persuade a nation of bicycle riders not to switch to mopeds." Unless Americans take material and costly steps to reduce our carbon emissions, we will have no moral standing in global climate discussions.
Recognizing that the United States will ultimately contain only a modest share of the world's economy and energy should not be an excuse for inaction. Instead, it should lead us to invest now in policies that can create a large global multiplier by helping to convince our soon-to-be larger neighbors to be better custodians of the planet.
I don't think this is very convincing. Even if we could use moral suasion to transform Chinese environmental policy, the argument of the "distinguished economist" is that our leverage over China is only as great as the delta of our per-capita emissions. In other words, China will feel no moral obligation to begin to reduce its carbon emissions unless they're producing more carbon per capita. That won't happen for a long, long time and if it ever does, carbon dioxide levels will be double what they are today no matter what we do.
Let's say that persuading China and India to control emissions is
critical to preventing exponential global carbon dioxide growth. So what is
the evidence that a cap and trade bill would do that? I'm not saying
cap and trade is doomed as a global PR measure. I'm saying I still
haven't found something that convinces me.