The organizers of this year’s Earth Day (Saturday, April 22) have selected global climate change as their central issue, and much of the national media appear to be following suit. While experts continue to debate the main causes, extent and consequences of a warming trend that is generally expected to continue through the 21st century, news coverage has frequently portrayed the scientific debate as a settled matter.

"After decades of rancorous debate, only a handful of the most doctrinaire die-hards still dispute the idea that human activity is heating up the planet," declared Time's Michael Lemonick in a special Earth Day issue.

"What will it take for us to get serious about saving our environment?" asked his colleague, Eugene Linden, in the same issue. "When will environmentalism move from being a philosophy promoted by a passionate minority to a way of life that governs mainstream behavior and policy?"

Activists don’t just argue that the globe is heating up; they insist that the warming seen during the 20th century has been unnatural, that a main cause has been industrial activity (the burning of fossil fuels), and that continued warming will cause catastrophic weather changes that will imperil human society.

Television news, in particular, seems to be pushing the idea that disaster is looming. On Tuesday, April 18, CBS’s Dan Rather began the newscast by noting "new and ominous signs that global warming is generating drastic and dangerous weather changes." That same night, ABC’s Ned Potter reminded viewers that "scientists and environmentalists warned for years that if the world became warmer, the result could be calamitous: hurricanes, tornadoes, heat waves," while NBC’s Robert Hager said that a new report from the Clinton administration "finds that in the midst of all the violent weather, the year 2000 is off to the warmest start ever in U.S. history."

According to my colleague Brent Baker, "In all that network time [on Tuesday night] devoted to impending weather disasters, not one doubter who holds a position contrary to the liberal environmental demands for more regulation or who does not believe warming causes extreme weather" appeared on any of the three broadcasts. Instead, professional activists such as Michael Oppenheimer of Environmental Defense were granted air time to warn that current weather disasters "present a picture of what could happen in the future, they present a picture of our vulnerability."

While such scare tactics may be unsettling for viewers, they help professional environmentalists in their efforts to change government policy. Global warming activists’ biggest policy success was the 1997 Kyoto Protocol on Climate Change, an international agreement that required developed countries to trim emissions of greenhouse gases such as carbon dioxide to levels approximately five percent below what they were in 1990.

Although the international community continues to negotiate the mechanisms by which Kyoto’s provisions will actually be implemented, it’s certain to "push up energy prices, inflation, and interest rates and lead to lower consumption, investment and net exports, thus reducing total production and income," although the magnitude of such costs has yet to be determined, according to a December 1999 report by Milka Kirova of the Center for the Study of American Business.

It’s still uncertain whether the U.S. will ratify Kyoto. Believing that the treaty would lose, President Clinton hasn’t sought a Senate vote on the matter. Looking to the next election, Vice President Al Gore recently re-affirmed his support of the Kyoto Protocol, while Texas Governor George W. Bush opposes it.

Still, given the magnitude of the potential costs, the news media should take the opportunity provided by Earth Day to inform the public about the ongoing scientific debate over important aspect of global warming, rather than continue to give the cold shoulder to climatologists who dissent from the environmental establishment’s line.

The following is a summary of some of the main points of the so-called "skeptics," with links to a number of articles presenting their arguments in greater detail.

The Earth’s surface is indeed warming, according to temperature data collected over the last century, but there’s disagreement about whether this is part of a natural variation and whether it can be conclusively linked with greenhouse gas emissions. According to Dr. Fred Singer, an atmospheric physicist and president of the Science and Environmental Policy Project,

"There is general agreement that the global climate warmed between about 1880 and 1940, following several centuries of the ‘Little Ice Age,’ which in turn was preceded by the ‘Medieval Climate Optimum’ around A.D. 1100. There is less agreement about the causes of this recent warming, but the human component is thought to be quite small.

"This conclusion seems to be borne out also by the fact that the climate cooled between 1940 and 1975, just as industrial activity grew rapidly after World War II. It has been difficult to reconcile this cooling with the observed increases in greenhouse gases."

Singer also wrote that an international climate panel’s finding that 20th century warming was correlated with human activity "depended entirely on the arbitrary choice of the time interval 1940 to 1990. During most of this period, temperatures were actually decreasing. A different choice of interval could have produced a zero, or even a negative, trend."

For more, you can download "What Do We Know about Human Influence on Climate Change," a report Singer prepared for the Center for the Study of American Business.

There was widespread media coverage of a National Academy of Sciences (NAS) panel report released on January 13 that concluded that the Earth's surface had warmed by about 1.0^ºF over the past century, but that atmospheric temperatures haven’t risen along with surface temperatures. Initial media reports termed the NAS report of surface warming "a blow to global warming naysayers," as CNN’s Natalie Pawelski put it on the January 16, 2000 edition of Earth Matters.

But if both sets of data are correct — and the NAS panel said that they were — the study actually reveals the flawed nature of the climate models that activists have used to push for restrictions on greenhouse gas emissions. Atmospheric scientist Richard Lindzen told The New York Times in February that both the lower atmosphere as well as the surface should have warmed if temperatures were rising due to elevated levels of greenhouse gases. The fact that atmospheric temperatures remained constant means that "what’s happening at the surface is not related to the greenhouse effect," Lindzen told the Times.

Commenting on the NAS report, Oregon state climatologist George Taylor questioned the integrity of the surface data. "I am very cautious about using data from individual stations to infer global trends," he wrote in comments that were posted on the Internet on January 14 by the Cato Institute’s Steve Milloy. "My explanation for the difference between U.S. temperatures (which show almost no warming this century) and global data (which show a lot) is that the latter is of considerably lower quality, and much more biased, than the carefully-constructed [Historical Climatology Network] data set." Added Taylor,

"Ten years ago, I believed the modelers that global warming was a serious problem that needed attention and intervention. As I studied the issue year by year, I became less and less convinced that the ‘problem’ was truly serious.

"My current bottom line: while human activities doubtless influence climate (on a local, regional, and even a global scale), the human-induced climate change from expected increases in greenhouse gases will be a rather small fraction of the natural variations. I don’t foresee global warming causing big problems. I believe if we controlled every molecule of human emissions we would still see substantial climate change, just as we always have."

Lowering of Official Warming Forecasts and Predicted Consequences of Warming

Apart from the divergence of atmospheric and surface temperatures, it’s also noteworthy that official estimates of how much the Earth would warm over the next hundred years have been lowered several times over the past decade. Dr. Roy Spencer, the senior scientist for climate studies at NASA’s Marshall Space Flight Center, wrote in Earth Report 2000, a book published in January by the Competitive Enterprise Institute, that "as computer models of the climate system have been improved in recent years, their projections of global warming by 2100 continue to be revised downward (3.3^ºC in 1990, 2.6^ºC in 1992, and 2.2^ºC in 1995.) The warming of 0.6^ºC in (1 F) in the last century is only about one-half of what current global warming theory predicts should have occurred."

Testifying before the House Subcommittee on National Economic Growth, Natural Resources and Regulatory Affairs last year, University of Virginia climatologist Patrick Michaels also reported that "observed surface warming is most consistent with a forecast below the lowest statistical range forecast by climate models. Recent observed changes are several times beneath what was forecast a mere ten years ago, assuming historical changes in carbon dioxide." (Emphasis in the original)

The divergence between observed atmospheric and surface temperatures, coupled with the repeated lowering of official estimates of future warming, indicate inadequacies with the prevailing climate models that helped make climate change a political issue a decade ago. Yet the assumption that global warming is a largely manmade phenomenon (and therefore one that can be controlled by changing human economic behavior), remains the guiding belief of environmentalists and many policymakers. So, too, is the assumption that global warming will introduce a variety of destructive changes to both human society and the broader environment.

But in his congressional testimony, Michaels noted that the warming that’s been observed so far has been limited mainly to the cold air masses that hover over Siberia and North America, and that most of the temperature increases have been during winter months. "Because of their coldness," Michaels told the subcommittee, those air masses "are very dry, and because of their dryness have very little ‘natural’ greenhouse effect and are consequently ‘warmed’ (if changing the temperature from -40^ºC to -38^ºC can be called a ‘warming’!) more rapidly than moist, summer air."

"During this century," Michaels further testified, "we experienced a temperature rise of approximately [0.6^ºC]. Crop yields quintupled. Life span doubled, in part because of better nutrition. Winters warmed. Growing seasons lengthened. The planet became greener. Increasing carbon dioxide had something to do with each and every one of these. There is simply no reason to assume that doing the same, this time in 50, instead of 100 years, will have any different effect in kind."

Such a sanguine view of global warming is rarely, if ever, mentioned by the media, which typically view environmental activists as independent voices while taking a more skeptical view of industry groups and the politicians who side with them. In an exhaustive survey of the environmental issues facing the U.S., the Heritage Foundation’s Angela Antonelli noted that professional environmentalists, like the corporations they frequently condemn, have their own interests to defend.

Indeed, Antonelli reported that ten of the largest environmental groups posted combined annual revenues in excess of $1 billion, and she noted that public fears about various environmental crises increases the political muscle and financial resources of these groups.

"Their activism today has less to do with achieving cleaner air and water, healthy fisheries and abundant wildlife than it has to do with gaining political clout and raising money. These environmentalists defend the status quo, deny that any improvements have been achieved, and scare Americans into giving them financial support, even when this approach results in policies that harm the environment and endanger public health," Antonelli wrote.

This shouldn’t imply that the media ought to ignore the views of professional environmentalists when covering issues such as global warming. It does imply that the media should treat self-serving liberal claims with the same skepticism that they reserve for conservative and free market ideas.

Unfortunately, the public hasn’t seen a balanced presentation of both views; a study directed by Tim Lamer, former director of the MRC's Free Market Project, found that more than 80 percent of global warming stories on the networks' evening newscasts from 1993-1997 pretended that skeptical climate scientists didn't even exist. "For the most part," Lamer wrote in "Facts Frozen Out: Network News and Global Warming, "the media debate over global warming has been one-sided, with the legions of skeptical scientists left out."

Will those who argue that the evidence on global warming doesn't support major changes in economic policy finally get their turn this Earth Day, or will they once again be frozen out of the coverage?
 

— Rich Noyes