Climatologists tell us that the stuff we put into the air has both warming and cooling effects. Greenhouse gases cause warming, while pollution particles (“aerosols”) shade the earth and cause cooling. So if greenhouse warming is bad, does that mean aerosol cooling is good? Not exactly. According to a new study, aerosol pollution benefits the poor tropical countries by slowing down warming. But it harms high-latitude developed economies, which would benefit from a bit of warming. Wait, benefit? Yes, according to the Carnegie Institution for Science, “Previous research has shown that climate change provides some economic benefits to countries in cool regions — which would be warmed to temperatures that are ideal for agricultural productivity and human labor.” Warming is bad but might be good. And cooling is good, but might be bad. Got that?
The difference, according to the authors, is whether you are in the hot, tropical regions of the planet, which also happen to be the poor regions. More heat there is not what you want. So the cooling effect of aerosols is beneficial, at least in the models. But in the real world, the authors also point out that aerosols are forms of air pollution that have negative health consequences. So the tropical countries should still reduce aerosol pollution. In the developed countries outside the tropics, warming is generally beneficial (shhhh, you’re not supposed to know that) and aerosol cooling is bad both because of the cooling and because of the health effects of pollution. So we don’t want aerosols here either.
Putting it all together, the authors conclude that at the global level things tend to average out, so the net economic effect of a bit of aerosol cooling is likely to be pretty small.