There is a strong scientific consensus as to the role of human activity in promoting climate change. Apparently the consensus is so strong that it even included the scientists working for the energy industry. The New York Times reports:
For more than a decade the Global Climate Coalition, a group representing industries with profits tied to fossil fuels, led an aggressive lobbying and public relations campaign against the idea that emissions of heat-trapping gases could lead to global warming.
“The role of greenhouse gases in climate change is not well understood,” the coalition said in a scientific “backgrounder” provided to lawmakers and journalists through the early 1990s, adding that “scientists differ” on the issue.
But a document filed in a federal lawsuit demonstrates that even as the 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.
“The scientific basis for the Greenhouse Effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied,” the experts wrote in an internal report compiled for the coalition in 1995…
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.