Robert Essenhigh, a professor of mechanical engineering at Ohio State, has written an essay disputing the idea that human activity is causing global warming. He is part of an academic group that opposes the Kyoto treaty. Although I have a PhD in physical organic chemistry and have done some work in environmental areas, I cannot dismiss his arguments out of hand. Is Professor Essenhigh right and can we all go out and buy SUVs? Or are there convincing arguments to the contrary? With the Kyoto treaty on the rocks, it’d be nice to know. –Jon Kapecki, Rochester, New York

I get a lot of letters like yours, Jon, basically asking me, a weekly alternative newspaper columnist, to resolve one of the great controversies of our age. No problem, that’s what I do. Given an 800-word limit, however, you’ll excuse my taking a few shortcuts.

So here we go: Are greenhouse-gas emissions from our fuel-guzzling cars, power plants, etc, a significant contributor to potentially catastrophic climate change? Answer: Beats me. But you know what? It doesn’t matter even if they are.

First, Essenhigh. The professor argued in a 2001 article in Chemical Innovation that average global temperatures are rising but that, contrary to widespread popular and scientific opinion, human activity isn’t the principal cause. Rather, the fluctuations we’re now seeing are part of a natural cycle that’s been going on for aeons. Essenhigh’s reasoning appealed largely to common sense: Carbon dioxide, the most widely discussed greenhouse gas, is part of earth’s vast store of carbon (about 150 billion tons), which is continually being cycled through the oceans, the atmosphere, and vegetation. The human contribution to atmospheric carbon in the form of CO2 is small, less than 5 percent of the total carbon reservoir. Ergo, humans aren’t causing global warming. I omit a lot of ancillary discussion, but that’s the nub.

One might raise scientific objections to this reasoning, but there’s no point. CO2 isn’t just an incidental result of human activity that you can get rid of with smokestack scrubbers. Rather, it’s an inherent product of the combustion of carbon-based fuels such as coal and oil. The only practical way to produce less in the short term is to use less organic fuel.

This brings us to the Kyoto Protocol to the United Nations Framework Convention on Climate Change, which the U.S. has famously refused to ratify. Kyoto calls for drastic cuts in emissions of CO2 and other greenhouse gases–5.2 percent below 1990 levels, or 29 percent below projected 2010 levels. These numbers alone suggest the implausibility of the goal. To brutally oversimplify, greenhouse-gas emissions = energy use = economic activity. (Again, I’m speaking short term–long term we’ll switch to nukes and other inorganic energy sources.) To produce fewer emissions now your one choice is to shrink your economy, i.e., become poorer. (Russia, to cite a grim example, is among the few industrialized nations that can meet its Kyoto target due to its economic collapse since 1990.) No nation is going to voluntarily impoverish itself, however noble the cause. What’s more, Kyoto exempts developing nations, which are expected to vastly increase their energy consumption and thus their emissions. In short, Kyoto if implemented would mean economic chaos for no likely net improvement. Ain’t gonna happen, as even Kyoto’s fans are beginning to concede.

So, should we quit worrying, buy SUVs, and party on? On the contrary. Fossil fuels are to the developing world today what the American forest was to this country two centuries ago–a cheap, easily exploited resource that permits extraordinary economic growth for the short time that it lasts. The U.S., through its huge trade deficits and job exports, is now financing the industrialization of Asia, a result we didn’t intend but would be foolish to impede–clearly we want teeming nations like China, India, and Indonesia to become prosperous, stable societies. Making that happen, though, will take decades of steady investment and jigawatts of energy, the price of which will climb steeply once fossil fuels run out. Hastening that none-too-distant day through frivolous use of the supplies we now have would be stupid (although fossil fuel depletion will also end the emissions problem). A more realistic approach is to say, OK, we’re going to burn this fuel and cope with whatever dire result, but let’s put the stuff to good use while we’ve got it. That means distributing improved technology to use energy more efficiently and pollute less. Amazingly, just such an approach was agreed to last year when the U.S., Australia, China, India, Japan, and South Korea formed the Asia-Pacific Partnership on Clean Development and Climate, which may go down as Dubya’s saving grace after having screwed the pooch in Iraq.