What about the economic feedback effects? By a deliberate policy of expensive energy, along with massive subsidies to unsustainable industries (see: biofuels, windmills) there is a net creation of poverty. If we look at the consequences of global warming, it's going to strike mostly in the poverty-stricken areas of the world. By denying economic development to those regions and by making it difficult for the developed world to grow further, we are condemning many people to avoidable misery.

Note that we're not talking about pollution that causes direct health problems (an often conflated issue in the environmentalist message today).