An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Global Warming: What Is It All About?

This is a presentation by Richard Lindzen of the Massachusetts Institute of Technology about approaches to determining exactly how much of observed global warming is actually due to anthropogenic greenhouse forcing, and how explicit feedbacks are involved in these results. This presentation was given for a seminar titled Global Warming: What Is It All About?

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.