From the NYTimes:
A document filed in a federal lawsuit demonstrates that even as the [polluting industry backed coalition] worked to sway opinion, its own scientific and technical experts were advising that the science backing the role of greenhouse gases in global warming could not be refuted.To people who have studied the science, man-made global warming has been practically undeniable for many years, but there has been so much manufactured confusion generated by the very entrenched and very rich polluting industries that people remain skeptical to this day.
Environmentalists have long maintained that industry knew early on that the scientific evidence supported a human influence on rising temperatures, but that the evidence was ignored for the sake of companies’ fight against curbs on greenhouse gas emissions. Some environmentalists have compared the tactic to that once used by tobacco companies, which for decades insisted that the science linking cigarette smoking to lung cancer was uncertain. By questioning the science on global warming, these environmentalists say, groups like the Global Climate Coalition were able to sow enough doubt to blunt public concern about a consequential issue and delay government action.
George Monbiot, a British environmental activist and writer, said that by promoting doubt, industry had taken advantage of news media norms requiring neutral coverage of issues, just as the tobacco industry once had.
“They didn’t have to win the argument to succeed,” Mr. Monbiot said, “only to cause as much confusion as possible.”