Last week, DeSmogBlog published a batch of internal fundraising memos from the Heartland Institute, a climate-skeptic group. But who leaked them? Turns out, it was Peter Gleick, a prominent climate researcher at the Pacific Institute, who says he lied to obtain the documents.

(Martin Kidston/AP)

Gleick writes that he initially tried to confirm whether this strategy document was real. When he couldn’t, he contacted the Heartland Institute directly using a fake e-mail account (Heartland has said that Gleick was impersonating a board member). The group then inadvertently sent him a slew of additional fund-raising and budget memos, which Gleick, in turn, forwarded to various blogs and reporters.

Gleick says that this latter batch of internal fund-raising documents are authentic and unchanged. “I made no changes or alterations of any kind to any of the Heartland Institute documents or to the original anonymous communication,” he writes.

A number of journalists, particularly the AP’s Seth Borenstein, have confirmed many of the details in the budget documents, such as the fact that the Heartland Institute is working to set up a climate-skeptic science curriculum for high schools. Most of Heartland’s attempts to dispute mainstream climate science, such as its annual conferences in Washington, are not a secret.

So who is Peter Gleick? He’s a member of the National Academy of Sciences who has been studying various aspects of global warming — especially its effects on our freshwater supplies — for many years. (In my own interviews with Gleick, I found that he often provided a measured, less-alarmist counterpoint to popular fears about climate-induced “water wars” and the like.) He’s also a longtime adversary of the Heartland Institute. Darren Samuelsohn points out that the Center for American Progress tapped Gleick to help conduct a “prebuttal” of the Heartland Institute’s climate-skeptic conference last year.

In his Huffington Post missive, Gleick called his behavior “a serious lapse of my own professional judgment and ethics.” The Heartland Institute, for its part, released a statement saying that “Gleick’s crime is a serious one” and that “A mere apology is not enough to undo the damage.” The group also suggests that Gleick himself forged the original strategy document, although that remains unproven.

Related: Leaked docs offer insight into how climate-skeptic groups operate.