Decades of Deceit

The report presents evidence that major fossil fuel companies possessed accurate knowledge of the catastrophic effects of their products on the global climate as early as the 1980s but instead funded campaigns of disinformation and deception. It highlights specific internal documents from Shell and ExxonMobil, a 1998 American Petroleum Institute 'Roadmap' to increase public uncertainty, and allegations of a criminal hacking scheme targeting climate advocates. The Union of Concerned Scientists calls for these corporations to cease greenwashing, pay for climate damages, and accelerate a global phaseout of fossil fuels.

• Major fossil fuel companies had detailed and accurate scientific knowledge of the dangers their products posed to the global climate for decades, yet they actively worked to deceive the public and block climate action to protect their profits.
• Specific internal evidence from the 1980s shows that industry trade associations and companies like Shell were warned of catastrophic global warming and the risk that it might be too late to act once warming became detectable.
• The fossil fuel industry employed strategic disinformation campaigns, including a 1998 American Petroleum Institute 'Roadmap' designed to create public and policymaker uncertainty regarding climate science, mirroring tactics used by the tobacco industry.
• Evidence suggests a coordinated effort to suppress climate accountability, including the use of front groups and a criminal hacking scheme targeting the Union of Concerned Scientists and other organizations, allegedly linked to ExxonMobil and the DCI Group lobbying firm.
• A small number of companies are responsible for the vast majority of industrial carbon dioxide emissions since 1959, providing a basis for quantifying their specific contribution to climate change.

APA

Union of Concerned Scientists (2025). Decades of Deceit. https://www.ucs.org/sites/default/files/2025-05/Decades-of-Deceit-ES_0.pdf

Chicago

Union of Concerned Scientists. Decades of Deceit. 2025. https://www.ucs.org/sites/default/files/2025-05/Decades-of-Deceit-ES_0.pdf.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=Decades of Deceit |date=May 2025 |url=https://www.ucs.org/sites/default/files/2025-05/Decades-of-Deceit-ES_0.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientists2025decades, author = {{Union of Concerned Scientists}}, title = {{Decades of Deceit}}, institution = {Union of Concerned Scientists}, year = {2025}, month = may, url = {https://www.ucs.org/sites/default/files/2025-05/Decades-of-Deceit-ES_0.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }