Could Obama appoint a "climate czar"?

With such a wide-ranging position still in the discussion stage, speculation has centered on likely candidates for Environmental Protection Agency administrator.

These include Democratic Governors Janet Napolitano of Arizona and Kathleen Sibelius of Kansas, both of whom have pushed to limit greenhouse emissions.

Carol Browner, who is part of the Obama transition team, is a former EPA chief and could conceivably be offered an environment post in the new administration.

Mary Nichols, now head of California's Air Resources Board, has been active in opposing a state ballot proposition that she maintains would increase greenhouse emissions. As a member of Republican Gov. Arnold Schwarzenegger's administration, she is seen as having the ability to work across party lines.

Kathleen McGinty, Pennsylvania's former Environment Secretary, has also been mentioned as a possible EPA chief.

Jonathan Lash, president of the World Resources Institute, which does policy research on environment and sustainability, is also considered a potential candidate.

(Editing by Anthony Boadle)