The American Petroleum Institute is the largest U.S. trade association for the oil and natural gas industry. It claims to represent nearly 600 corporations involved in production, refinement, distribution, and many other aspects of the petroleum industry.
The association describes its mission as to promote safety across the industry globally and influence public policy in support of a strong, viable U.S. oil and natural gas industry. API's chief functions on behalf of the industry include advocacy, negotiation and lobbying with governmental, legal, and regulatory agencies; research into economic, toxicological, and environmental effects; establishment and certification of industry standards; and education outreach. API both funds and conducts research related to many aspects of the petroleum industry. It has aggressively promoted climate change denial and acted against proposed mitigation measures since 1980. Over time, API has incrementally retreated on the existence, attribution, and severity of the issue as public opinion and political pressure made it less tenable to reject the scientific consensus outright.