Terrorism is bad. Lots of people die.

History tells us that global warming is generally good for humanity and global cooling is very bad for humanity. Warming would reduce demand for oil, a commodity that finances terrorism. It would increase agricultural production. That means more can be grown on the same acreage which reduces the need to expand farming into the natural environment. Forests and jungles would benefit from the extra warmth and CO2. Global warming would open up frozen tundra in Russia to agriculture. Agricultural production in North America would expand. Ethanol production would become economically viable, especially as science finds out how to convert all plant material to ethanol, instead of just the sugars and starch. A warmer world has more water circulating in the atmosphere. Droughts would become less common and milder. The minor losses at the coastal margins would be far out-weighed by the inland gains.

The GW proponents paint a picture of runaway warming as we burn fossil fuels. Unfortunately for them, they forget where the fossil fuels came from. The source is the ancient atmosphere, one much richer in CO2 than is presently the case. The Earth survived CO2 concentrations an order of magnitude higher than today. It’s unlikely we could ever find and burn all the coal and oil laid down in the Carboniferous era. Even if we did we would simply return the Earth to the rich environment of that era.

I would agree with environmentalists that we need to limit the pollution that is spewed into the atmosphere. It comes from industry and from more traditional sources, the third-world villagers who burn cow dung and vegetable matter stripped from the landscape. That pollution can cause global cooling, as Wikipedia explains:

Human activity — mostly as a by-product of fossil fuel combustion, partly by land-use changes — increases the number of tiny particles (aerosols) in the atmosphere. These have a direct effect: they effectively increase the planetary albedo, thus cooling the planet by reducing the sunshine reaching the surface; and an indirect effect: they can affect the properties of clouds by acting as cloud condensation nuclei. In the early 1970s some speculated that this cooling effect might dominate over the warming effect of the CO2 release: see discussion of Rasool and Schneider (1971), below. As a result of observations (aerosol concentrations may have increased, but not enormously) and a switch to cleaner fuel burning, this no longer seems likely; the overwhelming bulk of current scientific work concentrates on the forcing, prediction and understanding of possible global warming. Although the temperature drops foreseen by this mechanism have now been discarded in light of better theory and the observed warming, aerosols are believed to have contributed a cooling tendency (outweighted by increases in greenhouse gases) and also have contributed to “Global Dimming”.

I’m having trouble finding any reason not to welcome some global warming, especially if it helps stave off the next ice age. I doubt it can and the real challenge for humanity at some point in its future is how to deal with a real ice age; one that covers much of North America, Europe and Asia in mile-deep sheets of ice.