The head of the Environmental Protection Agency says he will investigate a threatening letter sent by the leader of an EPA-member group, vowing to "destroy" the career of a climate skeptic.

During a Capitol Hill hearing yesterday, Sen. James M. Inhofe, Oklahoma Republican and ranking member of the Environment and Public Works Committee, confronted EPA Administrator Stephen L. Johnson about the strongly-worded letter written July 13 by Michael T. Eckhart, president of the American Council on Renewable Energy (ACORE) that was sent to Marlo Lewis, senior fellow of the Competitive Enterprise Institute (CEI).

"It is my intention to destroy your career as a liar," Mr. Eckhart wrote. "If you produce one more editorial against climate change, I will launch a campaign against your professional integrity. I will call you a liar and charlatan to the Harvard community of which you and I are members. I will call you out as a man who has been bought by Corporate America. Go ahead, guy. Take me on."

CEI does not dispute climate change, however it differs with certain environmental groups, including ACORE, on the causes. After Mr. Inhofe read Mr. Eckhart's comments, which were first reported by Inside the Beltway two weeks ago, the EPA chief promised to probe the matter.

"Statements like this are of concern to me. I am a believer in cooperation and collaboration across all sectors," Mr. Johnson assured. "This is an area I will look into for the record."

When Mr. Johnson confirmed that EPA is a member of ACORE, Mr. Inhofe asked if "it is appropriate to be a part of an organization that is headed up by a person who makes this statement."

Late yesterday, Mr. Inhofe announced he will send letters to the departments of Agriculture, Commerce, Energy, and EPA, urging them to "reconsider their membership of ACORE."