From the 1980s to mid 2000s, ExxonMobil was a leader in climate change denial, opposing regulations to curtail global warming. For example, ExxonMobil was a significant influence in preventing ratification of the Kyoto Protocol by the United States. ExxonMobil funded organizations critical of the Kyoto Protocol and seeking to undermine public opinion about the scientific consensus that global warming is caused by the burning of fossil fuels. Of the major oil corporations, ExxonMobil has been the most active in the debate surrounding climate change. According to a 2007 analysis by the Union of Concerned Scientists, the company used many of the same strategies, tactics, organizations, and personnel the tobacco industry used in its denials of the link between lung cancer and smoking.

ExxonMobil Corporation is an American multinational oil and gas corporation and the largest direct descendant of John D. Rockefeller's Standard Oil. The company, which took its present name in 1999 per the merger of Exxon and Mobil, is vertically integrated across the entire oil and gas industry, and within it is also a chemicals division which produces plastic, synthetic rubber, and other chemical products. ExxonMobil is headquartered near the Houston suburb of Spring, Texas, though officially incorporated in the U.S. state of New Jersey. It is the largest United States-based oil and gas producing company. ExxonMobil is also the eighth largest company in the world by revenue and the third largest in the US.