“Brian Schatz is a lifelong environmentalist and a proven leader on climate change policy,” LCV Action Fund President Gene Karpinski said in a statement. “He has championed clean energy initiatives that have put Hawaii at the forefront of utilizing renewable energy and reducing dependence on petroleum. We will need his continued leadership in the U.S. Senate.”

Schatz is listed on the PAC's GiveGreen website, which helps bundle contributions for endorsed candidates.

Schatz was appointed by Gov. Neil Abercrombie (D) to the Senate late last year, following Sen. Daniel Inouye's (D) death. He faces a special election in 2014 to serve the rest of Inouye's term and may see a primary challenge from Rep. Colleen Hanabusa (D).

Hanabusa is also considering challenging Abercrombie, however, and the endorsement may be read as a warning to Hanabusa against entering the Senate race.