With his sonorous voice, Fred Singer, 86, sounded like a grandfather explaining the obvious to a dim-witted child. "Nature, not human activity, rules the climate," the American physicist told a discussion attended by members of the German parliament for the business-friendly Free Democratic Party (FDP) three weeks ago.

Marie-Luise Dött, the environmental policy spokeswoman for the parliamentary group of Angela Merkel's center-right Christian Democratic Union (CDU), also attended Singer's presentation. She said afterwards that it was "extremely illuminating." She later backpedaled, saying that her comments had been quoted out of context, and that of course she supports an ambitious climate protection policy -- just like Chancellor Merkel.

Merkel, as it happens, was precisely the person Singer was trying to reach. "Our problem is not the climate. Our problem is politicians, who want to save the climate. They are the real problem," he says. "My hope is that Merkel, who is not stupid, will see the light," says Singer, who has since left for Paris. Noting that he liked the results of his talks, he adds: "I think I achieved something."

Salesman of Skepticism

Singer is a traveling salesman of sorts for those who question climate change. On this year's summer tour, he gave speeches to politicians in Rome, Paris and the Israeli port city of Haifa. Paul Friedhoff, the economic policy spokesman of the FDP's parliamentary group, had invited him to Berlin. Singer and the FDP get along famously. The American scientist had already presented his contrary theories on the climate to FDP politicians at the Institute for Free Enterprise, a Berlin-based free-market think tank, last December.

Singer is one of the most influential deniers of climate change worldwide. In his world, respected climatologists are vilified as liars, people who are masquerading as environmentalists while, in reality, having only one goal in mind: to introduce socialism. Singer wants to save the world from this horror. For some, the fact that he made a name for himself as a brilliant atmospheric physicist after World War II lends weight to his words.

Born in Vienna, Singer fled to the United States in 1940 and soon became part of an elite group fighting the Cold War on the science front. After the collapse of the Soviet Union, Singer continued his struggle -- mostly against environmentalists, and always against any form of regulation.

Whether it was the hole in the ozone layer, acid rain or climate change, Singer always had something critical to say, and he always knew better than the experts in their respective fields. But in doing so he strayed far away from the disciplines in which he himself was trained. For example, his testimony aided the tobacco lobby in its battle with health policy experts.

'Science as the Enemy'

The Arlington, Virginia-based Marshall Institute took an approach very similar to Singer's. Founded in 1984, its initial mission was to champion then US President Ronald Reagan's Strategic Defense Initiative (SDI), better known as "Star Wars." After the fall of the Iron Curtain, the founders abruptly transformed their institute into a stronghold for deniers of environmental problems.

"The skeptics thought, if you give up economic freedom, it will lead to losing political freedom. That was the underlying ideological current," says Naomi Oreskes, a historian of science at the University of California, San Diego, who has studied Singer's methods. As scientists uncovered more and more environmental problems, the skeptics "began to see science as the enemy."

Oreskes is referring to only a handful of scientists and lobbyists, and yet they have managed to convince many ordinary people -- and even some US presidents -- that science is deeply divided over the causes of climate change. Former President George H.W. Bush even referred to the physicists at the Marshall Institute as "my scientists."

Whatever the issue, Singer and his cohorts have always used the same basic argument: that the scientific community is still in disagreement and that scientists don't have enough information. For instance, they say that genetics could be responsible for the cancers of people exposed to secondhand smoke, volcanoes for the hole in the ozone layer and the sun for climate change.

Cruel Nature

It almost seems as if Singer were trying to disguise himself as one of the people he is fighting. With his corduroy trousers, long white hair and a fish fossil hanging from a leather band around his neck, he comes across as an amiable old environmentalist. But the image he paints of nature is not at all friendly. "Nature is much to be feared, very cruel and very dangerous," he says.

At conferences, Singer likes to introduce himself as a representative of the Nongovernmental International Panel on Climate Change (NIPCC). As impressive as this title sounds, the NIPCC is nothing but a collection of like-minded scientists Singer has gathered around himself. A German meteorologist in the group, Gerd Weber, has worked for the German Coal Association on and off for the last 25 years.

According to a US study, 97 percent of all climatologists worldwide assume that greenhouse gases produced by humans are warming the Earth. Nevertheless, one third of Germans and 40 percent of Americans doubt that the Earth is getting warmer. And many people are convinced that climatologists are divided into two opposing camps on the issue -- which is untrue.

So how is it that people like Singer have been so effective in shaping public opinion?

Experience Gained Defending Big Tobacco

Many scientists do not sufficiently explain the results of their research. Some climatologists have also been arrogant or have refused to turn over their data to critics. Some overlook inconsistencies or conjure up exaggerated horror scenarios that are not always backed by science.  For example, sloppy work was responsible for a prediction in an Intergovernmental Panel on Climate Change (IPCC) report that all Himalayan glaciers would have melted by 2035. It was a grotesque mistake that plunged the IPCC into a credibility crisis.

Singer and his fellow combatants take advantage of such mistakes and utilize their experiences defending the tobacco industry. For decades, Big Tobacco managed to cast doubt on the idea that smoking kills. An internal document produced by tobacco maker Brown & Williamson states: "Doubt is our product since it is the best means of competing with the 'body of fact' that exists in the minds of the general public."

In 1993, tobacco executives handed around a document titled "Bad Science -- A Resource Book." In the manual, PR professionals explain how to discredit inconvenient scientific results by labeling them "junk." For example, the manual suggested pointing out that "too often science is manipulated to fulfill a political agenda." According to the document: "Proposals that seek to improve indoor air quality by singling out tobacco smoke only enable bad science to become a poor excuse for enacting new laws and jeopardizing individual liberties."

'Junk Science'

In 1993, the US Environmental Protection Agency (EPA) published what was then the most comprehensive study on the effects of tobacco smoke on health, which stated that exposure to secondhand smoke was responsible for about 3,000 deaths a year in the United States. Singer promptly called it "junk science." He warned that the EPA scientists were secretly pursuing a communist agenda. "If we do not carefully delineate the government's role in regulating ... dangers, there is essentially no limit to how much government can ultimately control our lives," Singer wrote.

Reacting to the EPA study, the Philip Morris tobacco company spearheaded the establishment of "The Advancement of Sound Science Coalition" (TASSC). Its goal was to raise doubts about the risks of passive smoking and climate change, and its message was to be targeted at journalists -- but only those with regional newspapers. Its express goal was "to avoid cynical reporters from major media."

Singer, Marshall Institute founder Fred Seitz and Patrick Michaels, who is now one of the best known climate change skeptics, were all advisers to TASSC.

Not Proven

The Reagan administration also appointed Singer to a task force on acid rain. In that group, Singer insisted that it was too early to take action and that it hadn't even been proven yet that sulfur emissions were in fact the cause. He also said that some plants even benefited from acid rain.

After acid rain, Singer turned his attention to a new topic: the "ozone scare." Once again, he applied the same argumentative pattern, noting that although it was correct that the ozone concentration in the stratosphere was declining, the effect was only local. Besides, he added, it wasn't clear yet whether chlorofluorocarbons (CFCs) from aerosol cans were even responsible for ozone depletion.

As recently as 1994, Singer claimed that evidence "suggested that stratospheric chlorine comes mostly from natural sources." Testifying before the US Congress in 1996, he said there was "no scientific consensus on ozone depletion or its consequences" -- even though in 1995 the Nobel Prize had been awarded to three chemists who had demonstrated the influence of CFCs on the ozone layer.

The Usual Suspects

Multinational oil companies also soon adopted the tried-and-true strategies of disinformation. Once again, lobbying groups were formed that were designed to look as scientific as possible. First there was the Global Climate Coalition, and then ExxonMobil established the Global Climate Science Team. One of its members was lobbyist Myron Ebell. Another one was a veteran of the TASCC tobacco lobby who already knew the ropes. According to a 1998 Global Climate Science Team memo: "Victory will be achieved when average citizens 'understand' (recognize) uncertainties in climate science."

It soon looked as though there were a broad coalition opposing the science of climate change, supported by organizations like the National Center for Policy Analysis, the Heartland Institute and the Center for Science and Public Policy. In reality, these names were often little more than a front for the same handful of questionable scientists -- and Exxon funded the whole illusion to the tune of millions of dollars.

It was an excellent investment.

In 2001, the administration of then-President George W. Bush reneged on previous climate commitments. After that, the head of the US delegation to the Kyoto negotiations met with the oil lobbyists from the Global Climate Coalition to thank them for their expertise, saying that President Bush had "rejected Kyoto in part based on input from you."