If you want to see how Exxon funds the denial campaign, go to exxonsecrets.org. You can choose from a list of corporations or people and see how they are linked to others.
A magnificent database and a fascinating way to report the results.
The website is a Greenpeace project.
The Union of Concerned scientists also has conducted their own research. Research
Organisations receiving various levels of funding from Exxon. Size of $ denotes level of funding.
Links to one think tank, the Heartland Institute. The people associated with Heartland are also associated with other organisations as shown by the links.
All organisations with a $ sign receive money from Exxon.
Heartland also receives money from Koch Industries, oil companies, oil related companies, and tobacco companies.