Sebastian Mallaby has an interesting column warning that an ill-conceived and poorly designed cap-and-trade system for carbon emissions will not do much to control emissions or encourage environmentally responsible development in poorer nations.

It would be great if carbon policy could get out of its timid rut: energy bills that raise fuel-efficiency standards, subsidize windmills and so on. It would be great if Congress could get serious about reducing emissions across the whole economy, either by taxing carbon or by capping it. But if Congress creates a mandatory cap-and-trade system that mimics Kyoto's clunkiness, it will funnel billions to Chinese industrialists, creating perverse incentives for greater emissions. And Nicaraguan villagers will be cheated.