All Commentary
Wednesday, April 1, 1998

Global Warming: Hot Problem or Hot Air?

The Earth Is Not on the Brink of Environmental Ruin

Jonathan Adler is director of environmental studies at the Competitive Enterprise Institute in Washington D.C., and the editor of The Costs of Kyoto: Climate Change Policy and Its Implications (1997), from which portions of this essay are adapted.

El Niño is the overhyped weather event of the decade. It has even made CNN’s “Larry King Live.” A natural warm spot in the Pacific Ocean that recurs every several years, El Niño exerts significant influence on global weather patterns; therefore, it’s news. It was also an opportunity for Vice President Al Gore to bang the drums for a global-warming treaty.

Speaking at the “El Niño summit” in Santa Monica last fall, Gore said that “El Niño events have become much more common and much stronger,” suggesting that human activity is warming the globe.[1] Preparing for the impacts of El Niño (which are typically mild in the United States), Gore said, will get people ready for the climatic disruptions brought by global warming.

This was not the first time that the Clinton administration linked global warming to the weather. In 1997, President Clinton suggested that flooding in North Dakota during the spring thaw was actually the product of global warming: “We do not know for sure that the warming of the earth is responsible for what seems to be a substantial increase in highly disruptive weather events; but many people believe that it is,” he said.[2] Later in the year, Gore visited Glacier National Park in Montana and proclaimed that the glacier’s hundred-year retreat was further evidence that human activity is causing the globe to overheat.

These speeches were more than presidential photo-ops. They were steps in a successful campaign for an international treaty to prevent climate change by controlling the use of fossil fuels. In Japan late last year, the administration signed the Kyoto Protocol, which, if ratified by the U.S. Senate, would require the United States to reduce carbon dioxide and other emissions an average of 7 percent below 1990 levels through 2012. (More on the effects of such a drastic reduction below.)

The Heat Is On

The push for a global-warming treaty got two big boosts in 1996, first from reports that 1995 was the hottest year on record and second from the publication of a United Nations report that purportedly demonstrated a scientific consensus behind global warming.

In January 1996 the British Meteorological Office reported that 1995 was the hottest year on record, edging out 1990 by a bare 0.07 degrees Fahrenheit. Temperature records have been kept in the United Kingdom since the nineteenth century and are compiled from a network of land-based measurements. Asked whether this was a sign of human-induced global warming, one British researcher commented, “I think we’re beginning to see it.”[3]

Not really. The “warmest year on record” announcement was based on incomplete data. Because December readings were not yet available, the British team only used readings from the first 11 months of the year; December’s temperature was estimated. But temperatures took a nosedive at the end of 1995. Indeed, it was the greatest December drop on record in the Northern Hemisphere. Global weather satellites, which have taken the earth’s temperature since 1979, found that 1995 was actually an average year—only the eighth-warmest since the satellites began taking climate measurements.

Soon thereafter the United Nations Intergovernmental Panel on Climate Change (IPCC) published its long-awaited report, Climate Change 1995 (the report was late, like most U.N. publications). The study, purportedly the work of 2,500 scientists worldwide, was heralded as proof positive of a scientific consensus that human activity was causing the earth to heat up. Yet here again, the hype was hollow.

The striking conclusion of the report was rather mild. In one chapter of the gargantuan study, the authors concluded that “the balance of evidence suggests that there is a discernible human influence on global climate.”[4] That highly qualified sentence, quoted incessantly in the media as proof of global warming, is the strongest claim in the entire report. And yet even that wishy-washy conclusion was controversial. The sentence was added at the last minute by the chapter’s editors, after the body of the report had already been approved by the IPCC, so that the report would more closely conform with the “policymaker’s summary.” Those who read the entire report realize that the scientific “consensus” is a lot more circumspect about humanity’s affect than the summary suggests. As Harvard University’s Peter Rogers told Forbes, the report “says we aren’t sure what is happening, and we need at least five more years to study the problem.”[5] Yet this cautious view made few headlines.

While major media outlets uncritically report the existence of a scientific “consensus” on climate change, surveys of climatologists suggest that there is still broad disagreement about the extent of human influence on the atmosphere. While Gore and Interior Secretary Bruce Babbitt characterize those who raise doubts about global warming as “immoral”[6] and “unAmerican,”[7] respectively, a 1997 poll of state climatologists finds substantial doubt among scientists. A clear majority of the climatologists surveyed disagreed with the statement, “The overwhelming balance of evidence and scientific opinion is that it is no longer a theory but now a fact that global warming is for real. There is ample evidence that human activities are already disrupting the global climate.”[8] Who said that? President Clinton, opening a White House conference on climate change.

Is the World Warming?

Before proceeding, some background is in order regarding what the debate is really about. The greenhouse effect is unquestionably real. It is what keeps the earth’s atmosphere livable. Certain atmospheric gases (“greenhouse gases”), including water vapor, carbon dioxide (CO2), and methane, trap solar radiation and help warm the planet. Without the greenhouse effect, the earth would be a frigid, desolate place.

Scientists have long believed that as the concentration of greenhouse gases in the atmosphere increased, the earth’s temperature might follow. The first prediction of such a greenhouse warming was made by the Swedish scientist Svante Arrhenius in 1896. He hypothesized that doubling the amount of CO2 in the atmosphere would increase average temperatures by 6 degrees Celsius.

Today, global warming is an issue because the atmospheric concentrations of greenhouse gases have been increasing. Since the beginning of the Industrial Revolution, the CO2 equivalent in the atmosphere has increased by 50 percent, largely due to the burning of fossil fuels, such as coal, oil, and gas. Also, since 1881, global average temperatures have increased by almost one degree Fahrenheit.

Environmental activists claim that this slight temperature increase over the last 100 years proves that global warming is upon us and that people are the cause. Yet most of the temperature rise preceded the increase in emissions. Two-thirds of the temperature increase occurred in the first half of the century, as the world emerged from the so-called “little ice age.” Most of the industrial emissions of greenhouse gases occurred after World War II. For this reason, most climate scientists believe that the temperature changes over the last 100 years are due to natural climate fluctuations.

A possible explanation for recent climate changes, one that is gathering scientific support, is the sun. In particular, slight variations in solar output, combined with fluctuations in the earth’s orbit, might be responsible for changes in global temperature. Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics reports that there is a remarkable correlation between solar cycles and surface temperatures over the past 240 years.[9] While the sun-climate connection needs more study, early results challenge premonitions of apocalyptic warming. As Science recently reported, “the sun could have been responsible for as much as half of the warming of the past century. If so, the role of greenhouse gases . . . would dwindle—as would estimates of how much they will warm the climate in the future as they continue to build up.”[10]

Garbage In, Garbage Out

Lacking empirical evidence of human-induced warming in the temperature records, proponents of global warming point to the global circulation models, highly complex computer programs that seek to replicate how the atmosphere will respond to increases in industrial emissions. The computer models almost uniformly predict that increased human emissions will cause the earth to warm. But whereas the models suggest that the earth already should have warmed measurably over the past 20 years due to the buildup of CO2 and other gases, the atmosphere has refused to cooperate. Global satellite measurements, which are precise enough to measure minuscule temperature fluctuations caused by the reflection of sunlight off the moon, find no warming trend whatsoever. Indeed, the satellites detect a slight global cooling over the past two decades, a finding confirmed by weather-balloon measurements.

Many scientists are skeptical of the models because they ignore a host of variables that affect the climate. For instance, few models come close to accurately replicating the role of clouds and precipitation in the climate system, and none adequately account for solar variability. David Legates, a climatologist at the University of Oklahoma, characterizes the computer simulations of precipitation as “exceptionally poor,” in part because they are unable to replicate weather fronts.[11]

In May 1997, Science, America’s most prestigious scientific journal, published a news story, “Greenhouse Forecast Uncertain,” highlighting the raft of uncertainties that remain in predictions of global warming. The article concluded that “most [computer] modelers now agree that the climate models will not be able to link greenhouse warming unambiguously to human actions for a decade or more.”[12] One month later, the Bulletin of the American Meteorological Society published a paper suggesting that computer models may be misrepresenting the effect of water-vapor feedback within the climate system.[13]

Indeed, as these models have become more accurate at estimating present temperatures, they have also forecast less extreme temperature rises due to the accumulation of greenhouse gases. Based on the models’ findings, the IPCC predicts a warming of 0.8 to 3.5 degrees Celsius by the year 2100. That is significantly less warming than predicted in the apocalyptic scenarios with which we are all too familiar. Indeed, the IPCC’s lower-bound warming estimate is just over half that predicted just a few years ago. Newer models predict even less warming over the next century.

None of this is to say that human activity is having no effect on the climate whatsoever. The reality is that human activity, from changes in land-use patterns to the combustion of fossil fuels, is probably having some effect on the world around us and will into the future. For example, the existence of an urban “heat island” effect is indisputable. Cities, with lots of cement and asphalt and little vegetation, tend to be significantly warmer than surrounding areas. Moreover, these “heat islands” often affect local rainfall patterns and thunderstorm activity, as does large-scale irrigation.

Human-induced changes are real, says warming skeptic Patrick Michaels of the University of Virginia, “but the changes are so small and of such a benign nature that they are insufficient to support any expensive or disruptive policy. If anything, they indicate that the best policy is probably to do nothing.”[14]

Is Warming Bad?

The more that is known, the less it seems humans have to fear from global warming. Environmentalists recite a litany of horrors that it will produce: heat waves, hurricanes, drought, and disease. Such scare stories are way overblown, if not outright frauds.

It seems commonsense that if the earth were to get warmer, scorching summers would become the norm. Yet the majority of scientific evidence suggests quite the opposite. Any warming will occur in the winter and at night, making winters more benign rather than summers more intense. When scientists examined temperature records to see if higher global temperatures correlated with urban heat waves, they found no evidence of a link, environmentalist claims notwithstanding.[15]

What about storms? Scientific reviews of storm data cannot find any correlation between warmer temperatures and increased hurricane activity. If anything, the existing data show a slight decline.[16]

Is Warming Good?

Not only is the argument for an apocalyptic global warming exceedingly weak, but there are substantial reasons to believe that a modest warming will be beneficial. Nighttime warming should lengthen growing seasons at the same time that increased levels of CO2 accentuate the growth of plants. A rise in soil moisture is more likely to occur than a rise in severe droughts. This will probably be a boon for agriculture.

“The farming, timber, and commercial energy sectors all benefit from warming,” according to Robert Mendelsohn of the Yale School of Forestry and Environmental Studies.[17] Mendelsohn believes that the overall economic impact of warming will be small compared to the size of the American economy, but that gains will more than offset projected losses. Thomas Gale Moore of the Hoover Institution is even more optimistic. “History demonstrates that warmer is healthier,” says Moore.[18] His examination of mortality rates in the United States indicates that “warmer temperatures reduce deaths” compared with colder temperatures.[19] He notes that over the past several centuries, the warmest periods have also been those of the greatest prosperity and technological advance.

Obviously, any changes in weather patterns could well prove disruptive, as are all unforeseen global changes. But most predictions of economic disaster assume that people are too stupid to adjust their behavior to mitigate the costs and enhance the benefits of a changing world. That view does not square with reality. Even if the worst IPCC prediction comes true, it is unlikely to spell disaster for civilization.

What’s at Stake

Advocates of the global-warming treaty claim that the risks of human-induced warming are too great, and therefore preventative steps are necessary. Yet even a cursory examination of the policy options reveals that the costs of global warming would be dwarfed by the costs of a global-warming treaty.

Preventing any chance of climate changes brought about by industrial activity would require stabilizing concentrations of CO2 and other greenhouse gases in the atmosphere. People could not put more greenhouse gases into the air than is removed by natural processes. Such a policy would require drastic reductions in greenhouse-gas emissions. Industrialized nations would have to cut their emissions in half, if not more, and developing countries would have to hold their emissions constant. That is a recipe for economic disaster and would require unprecedented government intervention in the marketplace.

Stabilizing greenhouse gases will require limitations on energy use. The burning of oil, coal, and natural gas will have to be constrained through the imposition of energy taxes, supply controls, or other regulatory measures. That means higher energy prices, which will increase the cost of everything from heating a home and cooking a meal to driving to work and buying groceries. It would be the 1970s energy crisis all over again, if not far worse.

Some environmentalists suggest that fossil fuels can be replaced with alternative energy sources at little cost. Such arguments are absurd. On the whole, alternative energy sources are more expensive and less reliable than their carbon-based counterparts.[20] Nuclear power might be an efficient non-emitting energy source, but environmental groups are unlikely to endorse its use anytime soon.

Despite the inadequacy of alternative energy sources, many people, including President Clinton, insist that a reduction in emissions can be achieved at little or no cost. Some even argue that it will produce a profit. This is not reality but an economic fantasyland in which government planners can radically reorganize human affairs on a global scale without causing severe pain and discomfort.

Better Safe than Sorry?

Despite the costs, some see cutting the emission of those gases as a form of insurance against a potential greenhouse world. Yet if the IPCC draft projections are to be taken seriously, then one must accept that much of the potential warming over the next century is a fait accompli. Lowering emissions will not prevent warming; at most it will modestly reduce the predicted temperature rise over the next century. More important, current projections suggest that there is little cost from delay.

As the value of a proposed insurance policy diminishes, and the cost of the premium increases, fewer will consider the policy a sound investment. Insurance in the form of choking off greenhouse emissions will come at tremendous cost, but if purchased today, it will provide only modest benefits—assuming that the results of global warming will be all bad. When one also considers the potential for adaptation and benefits like the increase in agricultural productivity that higher carbon-dioxide levels produce, it is possible that effects of global warming will be a wash. On the other hand, reducing economic activity by blocking its lifeblood—energy use—will have real adverse consequences. Health is a function of living standards; so too is environmental protection. Wealthier is healthier. Suppressing economic growth reduces the standard of living and increases mortality. This is especially true in the developing world, where the costs of the global warming treaty will be most severe.

Even though developing countries are exempted from the treaty, they will still suffer. “The markets to which these developing countries sell a large share of their exported goods will shrink, so that most developing countries would also be harmed by the adoption of emission limits” solely in industrialized nations, according to economist David Montgomery.[21] The costs of any treaty to control greenhouse gas emissions will be felt worldwide.

What to Do?

The arguments for dramatic greenhouse gas reductions are all variants of the precautionary principle that it is better to be safe than be sorry. If only it were that simple. It is true that economic growth and technological advance pose environmental risks. But stagnation is hardly a safer course. In the words of the late Aaron Wildavsky, “the results of doing too much can be as disastrous as doing too little.”[22]

Policymakers should pursue the “safest” course, which in this instance is not greater government controls on economic activity, but fewer. Economic growth, market institutions, and technological advance are the best forms of insurance that a civilization can have. Free and open markets are also the best means to encourage greater efficiency in energy use and the development of non-emitting energy sources.

Copper wire was not replaced with sand, in the form of fiber optics, due to concerns about resource depletion or the environmental impacts of mining. Fiber optics were invented because the market creates incentives for innovation and entrepreneurial activity. The same is true with energy. Petroleum displaced whale oil before Greenpeace was ever founded, because price increases caused by over-harvesting spurred the search for cheaper and more efficient alternatives. One day, fossil fuels will be displaced in much the same way without government intervention.

Some who support the global-warming treaty are no doubt motivated by a misguided desire to protect civilization from an uncertain environmental threat. They have succumbed to the fatal conceit that government planning can avert environmental disaster. Others, no doubt, see global warming as an opportunity to enact far-reaching economic policies.

“What we’ve got to do in energy conservation is try to ride the global warming issue,” said former Senator Tim Wirth in 1988. “Even if the theory of global warming is wrong, to have approached global warming as if it is real means energy conservation, so we will be doing the right thing anyway in terms of economic policy and environmental policy.”[23] Al Gore, in his book Earth in the Balance, suggested that all of modern civilization was “dysfunctional” and needed to make environmental protection its “central organizing principle” or risk ecological armageddon.[24]

The earth is not on the brink of environmental ruin. Even if it were, an international treaty and global bureaucracy could not save it. The treaty can, however, impoverish nations, diminish prosperity, and subvert economic liberty—none of which is good for environmental protection. Indeed, there is more to fear from a global warming treaty than from global warming itself.


  1. Alex Barnum, “Gore Links El Niño to Global Warming,” San Francisco Chronicle, October 15, 1997, p. A2.
  2. Peter Baker, “Flood Victims Cheer Clinton’s Pledge of Aid,” Washington Post, April 23, 1997, p. A1.
  3. William K. Stevens, “’95 Is Hottest Year on Record as the Global Trend Resumes,” New York Times, January 4, 1996, p. A1.
  4. Intergovernmental Panel on Climate Change, Climate Change 1995: The Science of Climate Change, ed. J. T. Houghton, et al., (Cambridge: Cambridge University Press, 1996), p. 4.
  5. Christine Hill, “The Report that Nobody Reads,” Forbes, November 3, 1997, p. 352.
  6. Quoted in Ronald Bailey, “Bill and Al’s Global Warming Circus,” Forbes, November 3, 1997, p. 346.
  7. “Dianne Rehm Show,” WETA radio, Washington, D.C., July 21, 1997.
  8. William E. Clayton, Jr., “Clinton Speaks Out on Global Warming,” Houston Chronicle, July 25, 1995, p. A2.
  9. Sallie Baliunas and Willie Soon, “Solar Variability and Global Climate Change,” paper presented at the Fraser Institute Conference on The Science and Politics of Global Warming, Vancouver, Canada, October 29, 1997, p. 5.
  10. Richard Kerr, “A New Dawn for Sun-Climate Links?” Science, March 8, 1996, p. 1360.
  11. “Rains of Climate Terror Miscalculated . . . Interview with David Legates,” World Climate Report, vol. 1, no. 8.
  12. Richard Kerr, “Greenhouse Forecasting Still Cloudy,” Science, May 16, 1997, p. 1040.
  13. Roy W. Spencer and William D. Braswell, “How Dry Is the Tropical Free Troposphere? Implications for Global Warming Theory,” Bulletin of the American Meteorological Society, June 1997.
  14. Patrick J. Michaels, “The Decline and Fall of Global Warming,” paper presented at the Fraser Institute Conference on The Science and Politics of Global Warming, Vancouver, Canada, October 29, 1997, p. 3.
  15. Thomas Karl and Richard Knight, “The 1995 Chicago Heat Wave: How Likely Is a Recurrence?” Bulletin of the American Meteorological Society, June 1997.
  16. Robert Balling, “Calmer Weather: The Spin on Greenhouse Hurricanes,” Competitive Enterprise Institute, May 1997.
  17. Robert Mendelsohn, “The Economic Impacts of Climate Change in the US,” Yale School of Forestry and Environmental Studies, September 6, 1996, p. 8.
  18. Thomas Gale Moore, “Warmer Days and Longer Lives,” World Climate Report, vol. 2, no. 4.
  19. Thomas Gale Moore, “Health and Amenity Effects of Global Warming,” Hoover Institution, Stanford University, May 30, 1996.
  20. See Robert L. Bradley, Jr., “Renewable Energy: Not Cheap, Not ‘Green,’” Policy Analysis No. 280, Cato Institute, August 27, 1997.
  21. W. David Montgomery, “Global Impacts of a Global Climate Change Treaty,” in The Costs of Kyoto: Climate Change and Its Implications, ed. J. Adler (Washington, D.C.: Competitive Enterprise Institute, 1997), p. 69.
  22. Aaron Wildavsky, But Is It True?: A Citizen’s Guide to Environmental Health and Safety Issues (Cambridge, Mass.: Harvard University Press, 1995), p. 428.
  23. Rochelle Stanfield, “Less Burning, No Tears,” National Journal, August 13, 1988.
  24. Al Gore, Earth in the Balance: Ecology and the Human Spirit (New York: Houghton Mifflin Company, 1992), pp. 232, 269.

  • Jonathan H. Adler is the inaugural Johan Verheij Memorial Professor of Law and Director of the Center for Business Law and Regulation at Case Western University School of Law. He teaches teaches constitutional, administrative, and environmental law.