So Many Ways To Kill Ourselves

I watched an interesting episode of Nova last week on PBS, in which scientists speculated that one of the forces mitigating the effects of Global Warming for decades - until recently, that is - was air pollution, which actually causes something called Global Dimming. The theory is that particles in the air produced by typical industrial pollution cause bigger drops of water to form in clouds before falling to the ground (as rain), and those larger bodies of water deflect more of the sun's rays back out into space. When that happens, the overall effect is to cool the planet (hence, dimming, as less light - and heat! - reach the ground). That process was going on, big-time, in the 20th century as industrialization took off in North America and Europe. Then, in the 1980s and 90s, laws were changed to curtail the pollution - since, after all, it was killing people! - and the cooling effect of Global Dimming was unwittingly reduced. Not coincidentally, the effects of Global Warming - rising temperatures, but also more violent storms of all kinds, flooding, drought, etc. - have climbed in the past couple of decades.

So now we have India and China industrializing, and air pollution's a huge problem in both countries (the statistic of "one million Indians dying a year of respiratory illnesses" was quoted). The expectation is that China and India will react more quickly than their industrial predecessors did, and their currently out-of-control problem will be addressed. However, doing so will probably further accelerate Global Warming, just as the seemingly "pro-environmental" actions in North America and Europe did previously. Talk about a "damned if you do, damned if you don't" scenario!

As an example of how much effect air pollution can have, Nova showed one scientist who used the period immediately after September 11, 2001, as an opportunity to see how ground temperatures in the U.S. might differ if you simply removed the contrails of airplanes (since no planes were allowed into the air following the terrorist attacks). His findings were that those few days showed a greater range of temperatures - hot during the day, cool at night - than he'd ever measured before. And that came about just by taking airplane exhaust pollution out of the mix!

It should be a very entertaining next twenty or thirty years... assuming that you find disaster films entertaining, that is!