"Global warming" may be real, but not artificially caused

A story in Sunday's Sun-Times reports these poll findings:

●53 percent think warming is caused more by human activity than by normal Earth cycles.

●70 percent think the effects of global warming can be reduced.

●59 percent think their efforts as individuals can make a difference in global warming.

●At least 90 percent are willing to take the following steps to reduce greenhouse gas emissions: recycle, turn thermostats down in winter by 2 degrees, caulk around windows, and combine driving trips when running errands.

●Between 80 percent and 90 percent are willing to take these energy-saving actions: wash clothes in cold water, turn down water heater temperature, buy energy-efficient light bulbs, buy energy-efficient appliances, and buy energy-efficient cars.

●70 percent are willing to drive less, and walk, bike, car pool or take mass transit.

I applaud the willingness of so many to take practical energy-saving actions. But none of this will necessarily stop "global warming."

The idea that the planet is warming because of human activity -- industrial and auto pollution, deforestation, etc. -- and that curtailing these activities or ceasing particular activities altogether (let's all go back to caves and live off the land!) will somehow stop this "global warming" strikes me as hubristic, and potentially dangerous, nonsense.

The History Channel has recently been running a program entitled Little Ice Age: Big Chill, about a 550 year global cold snap that changed European history -- and prompted the beginning of American history as we now know it.

The ad copy for the DVD of the program states:

Scientists call it the Little Ice Age--but its impact was anything but small. From 1300 to 1850, a period of cataclysmic cold caused havoc. It froze Viking colonists in Greenland, accelerated the Black Death in Europe, decimated the Spanish Armada, and helped trigger the French Revolution. The Little Ice Age reshaped the world in ways that now seem the stuff of fantasy--New York Harbor froze and people walked from Manhattan to Staten Island, Eskimos sailed kayaks as far south as Scotland, and "the year without a summer" saw two feet of snow fell on New England one June and July.

Those who fret about global warming presumably do not recall the fate of the Viking colonists of Greenland.

During the warm centuries that preceded the Little Ice Age, Vikings journeyed to Greenland, Iceland, and to the shores of North America. Calling the island "Greenland" was always a bit of hyperbole on the part of its Viking promoters, but the early colonists there did have grazing land for sheep and were able to maintain flocks.

The Little Ice Age changed this -- and the Vikings ultimately starved.

Now Greenland is apparently warming again -- but is it yet as warm as it was before the Little Ice Age? And why was it so warm then? If that episode of "global warming" was not caused by medieval knights, then why is mankind responsible for the current episode?

The world changes. It has changed before. It will change again. This is part of the natural order of things. Humankind must have some influence, particularly in localized areas -- urban heat islands, for example -- but what is it about the human ego that makes some people feel as if the human race is responsible for everything, good or bad, that happens in, or to, the world?

Climate change should certainly be studied. We should study how best to adapt to climate changes that may be coming. We should try and figure out how human activity retards or accelerates climate change (my working hypothesis is that, in different areas, human activity does both). But neither good science nor good public policy can be constructed on an assumption that "global warming" is caused by human activity.