Reducing Air Pollution Increases Temperatures

According to a study performed at the Royal Netherlands Meteorological Institute, clearer skies due to lowered man-made pollution cause the temperature to rise. This would be a case in which man's activities affect the climate of at least densely populated areas or those generating much pollution. As Europe and the United States and Canada have generally cleaned their skies of much of the air pollution common a few decades ago, countries such as Russia, China, and India have increased their air pollution. I do not know the net effect upon the global climate, but there is probably some effect caused by man. In the longer view, the cooling effect of air pollution in the earlier stages of the industrialization of Europe and the United States was a man-made effect which has now been largely undone. Later developing industrial nations such as Russia, China, and India are now the main polluters and coolers, but will likely do more to clean up their air pollution as they develop further.

The Dutch study collected data from 342 weather stations at airports across Europe measuring the fog, mist, and haze back to 1976. The report in the journal Nature Geoscience says that the number of days with visibility of less than 2 kilometers have fallen from 20 days per year to 10 days per year in the last 30 years. As a result, less sunlight is reflected back into space from the top of such fog, mist, and haze layers and more reaches the ground, to provide more warming at the surface of the earth.

The heat island effect of major cities is very well-known and is in fact a problem for accurate earth surface land temperature histories, which many say is not adequately corrected for in the measurements of the general warming trend since the end of the Little Ice Age and the advent of industrialization with the burgeoning growth of population centers that resulted. Man clearly does have some effect on at least the local climate in these high population centers. Indeed, even small towns appear to have small local effects.

It is also clear that such activities as plowing fields for farming and cutting down forests have an effect upon the climate. Of course, man has been doing these things for a very long time, so they have little effect on the climate any more in terms of changing it, except when the level of such activities changes greatly in a given locale. But compared to an earth with no human activity, the climate has been somewhat changed by the presence of man. I have no yearning to remove man and his effects in order to return the planet to its natural, no-human climate condition. There is no reason to value this at all and every reason to value an earth which supports the flourishing of man, thanks to man's use of his ability to reason for the purpose of improving his environment for his benefit.

But, while I deny that the effects of man's activities are more important than natural forces affecting the climate and I deny that his activities are causing a climate catastrophe, I do not deny that man has some effect upon the earth's climate. If man does cause some warming, I have no problem with that. In fact, wise men will generally acknowledge that some warming is a generally good thing. There is good reason upon examining the historical record of man to conclude that man tended to flourish better in warmer periods and to suffer more in cooler periods. More power to man if his activities are actually causing a bit of warming, which makes man a bit more comfortable.