At the United Nations Earth Summit in Rio de Janeiro, Brazil in June, President Bush was thrust into the hot seat on the global warming issue.

The President's refusal to endorse oppressive energy taxes and comprehensive international controls on carbon dioxide emissions earned the wrath of Fidel Castro, much of the heavily polluted Third World and a gaggle of radical environmentalists, but his reasoning was sound. There's no reason to allow bad science or no science to inflict billions in costs on the U.S. economy.

If his detractors ever have their way, the taxes and controls they want in the name of countering global warming would hit industrial Michigan especially hard. Jobs, income and industry would be sacrificed for a theory that is backed more by propaganda than evidence.

The theory behind global warming is that a buildup of greenhouse gases (particularly carbon dioxide) will cause the earth to heat up, with potentially far-reaching and harmful effects. Currently, the scientific community is very much divided over whether or not global warming has already occurred, whether it will occur to any significant degree in the future, whether it would be deleterious or beneficial to humans, and even whether--if it is deleterious--it would be better to adjust to the warming or try to prevent it.

Arizona State physicist Sherwood Idso and Russian climatologist Mikhail Budyko argue that we should actually welcome a carbon dioxide (CO2) buildup with open arms. Like so many scientists who welcome or at least don't worry about warming, they take a broader view--considering the historical variations in the earth's temperature and cycles in carbon dioxide concentration.

A July 1991 Environmental Task Force report released in Michigan by The Mackinac Center, a task force member, cited research that suggests that global cooling may actually be more the problem. In the past two to three million years, the earth's temperature has gone through at least 17 climate cycles, with ice ages typically lasting about 100,000 years interrupted by warm periods lasting about 10,000 years. Since by some calculations the current warm period is about 13,000 years old, the next ice age is overdue.

Those who worry that the human use of carbon-based fuels is sending too much CO2 into the atmosphere may be surprised to learn that atmospheric CO2 levels have varied radically as life on earth has evolved. Moreover, just as warmth has always been unambiguously good for life, so has CO2. Plants thrive when exposed to more CO2, a phenomenon greenhouse operators have observed for years.

Indeed, a committee of the U.N.'s own Intergovernmental Panel on Climate Change has estimated that a world warming of 3.5 degrees Fahrenheit would so dramatically boost agricultural and forest growth that the resulting gains would outweigh losses of coastal areas due from any melting of the earth's ice caps. The IPCC report didn't see the light of day in Rio.

Nor was much attention paid at the Summit (or in the press afterward) to a revealing study by the prestigious Marshall Institute. Headed by some of this country's most renowned scientists, the Institute reported in May that measurements show that almost all of the half-degree by which the earth's temperature has risen since 1880 occurred before 1940. Most man-made CO2 has entered the atmosphere since 1940!

A recent report from the U.S. Environmental Protection Agency indicates that U.S. greenhouse gas emissions are likely to remain stable for decades. But if further research fails to silence calls for emissions reductions, there are many sensible policies we could adopt.

Nuclear generation of electricity emits no pollutants and no carbon dioxide. About 110 nuclear power plants currently provide 20 percent of U.S. electricity. Yet more than 100 additional plants have been cancelled or deferred indefinitely since the early 1970s--the direct result of an intense anti-nuclear power campaign carried out by many of the same individuals who are now demanding domestic reductions in CO2 emissions. The issues surrounding nuclear power are primarily political, not technological. A rational policy on nuclear power would be preferable to wrecking the economy with draconian taxes and controls.

Because CO2 is absorbed by plants on land and in the oceans, the possibility of increasing the rate of absorption offers another viable alternative in the near future. Fertilizing the oceans to enhance their ability to absorb CO2 will soon be technologically feasible. Since all of the CO2 emitted by the burning of fossil fuels since 1850 equals just 2 percent of the CO2 dissolved in the top 1,000 meters of the world's oceans, an increase of only 2 or 3 percent in the rate of uptake of CO2 by the oceans could be sufficient to offset man-made emissions.

What is really at work on the global warming issue is more than just an honest disagreement within the scientific community. Radical environmentalism--which seeks to impose ever bigger government on society--has become the last refuge of many of the world's socialists. It's this hidden agenda cloaked in supposed concern for the planet that lead a distinguished group of scientists last April, including 30 Nobel laureates, to publicly condemn the "emergence of an irrational ideology which is opposed to scientific and industrial progress and impedes economic and social development."

Public policy on the environment should not be driven by bad science or no science. Politicians have an obligation to objectively weigh the evidence and reject emotion, propaganda and hidden agendas. Global warming, like all issues, could benefit from a little more light and a lot less heat.