WASHINGTON -- Former Vice President Al Gore planned to visit with President-elect Barack Obama and Vice President-elect Joe Biden on Tuesday, but those briefed on the meeting insisted the topic would be the planet rather than Gore's formal return to Washington.

Gore sought the presidency in 2000 but lost to then-Texas Gov. George W. Bush in a disputed election that was settled in the Supreme Court. He then became a leader in the movement to draw attention to the issue of climate change and global warming. He won the Nobel Peace Prize in 2007, and his documentary "An Inconvenient Truth" won an Academy Award the same year.

He lends Obama instant credibility among environmental activists.

Obama has pledged to use part of his proposed economic stimulus package to develop alternative energies and "green" technologies. Obama's aides said the private meeting would help shape the president-elect's economic policies.

The former vice president endorsed Obama in June, shortly after he clinched the nomination after a long primary battle with Hillary Rodham Clinton. Gore was vice president under President Bill Clinton.