American Enterprise Institute, Heritage Foundation, Hoover Institution, Manhattan Institute, Cato Institute, Hudson Institute, Atlas Economic Research, Americans for Prosperity, John Locke Foundation, Heartland Institute, and Reason Foundation.
They, in turn, pay professors and journalists to write, both for the "news media," and for professional journals, to debunk or (in the scholarly publications) to raise questions about, global warming or its cause -- questions that are no longer even questions among actual climate scientists.