On December 9, 2008 the Environmental Protection Agency (EPA) published Richard Lindzen’s slides from a presentation titled “Global Warming: What Is It All About?” Lindzen, a former professor of meteorology at the Massachusetts Institute of Technology and noted climate change denier, was to present opinions on “how much of observed warming is actually due to anthropogenic greenhouse forcing”. Lindzen’s presentation was part of a series of three seminars on the science of global warming hosted at the EPA headquarters. (No information on the intended audience or specific attendees is available.)
The presentation posits several thoroughly debunked theories which cast doubt on the causes of climate change. In a series of tweets posted on September 3, 2020, George Mason University Professor John Cook highlighted several errors in the presentation, including claims that:
- The existence of anthropogenic climate change is disproved by the fact that atmospheric CO2 levels have historically lagged behind temperature records.
- Ocean cycles could explain observed warming.
- Current trends in climate change fit within historical norms.
Despite these errors, the presentation is still live on the EPA website in 2020. A disclaimer within the presentation slides notes that the content does not “necessarily reflect the views or policies of the EPA”.