The document is a letter from the American Petroleum Institute to the U.S. Environmental Protection Agency providing comments on the draft Third U.S. Climate Action Report. The API expresses support for aspects of the report that recognize uncertainties in climate science. However, the letter raises concerns that some sections of Chapter 6 go beyond what is known about regional climate impacts and projections. The API recommends revising sections of Chapter 6 to better reflect the "weakest links" in understanding regional climate changes identified by the National Research Council. The letter also provides specific editorial comments and suggested changes to sections of Chapters 1, 2 and 6.