1) The developed nations got a free ride during their developing phase, burning fossil fuels with reckless abandon while abetting global warming that now afflicts the entire world. In that sense Kyoto evens the score.

2) Poor nations arguably have shorter time horizons than rich nations; they care less than the rich about the far-off benefits of curtailing consumption now. And in the bargaining portion of any non-zero-sum game, this sort of relative indifference is a concrete asset. Or, to put the same basic point in another way: Since solving global warming brings less psychological utility to developing-world residents than to developed-world residents, a utilitarian calculus would find the poor nations doing much less free riding than the simple economic calculus that the Bush administration is doing.