Former Vice President Al Gore, one of the country’s best-known Democrats, stayed pretty quiet during his party’s long primary season. But now that the party has a nominee, Gore is speaking up, telling Obama’s supporters that “from now through Election Day, I intend to do whatever I can to make sure [Obama] is elected president of the United States.”

In a campaign rally in Detroit, Gore said “the outcome of this election will affect the future of our planet.” Since he lost his bid for the presidency in 2000 to George W. Bush, Gore has been a vocal advocate for curbing climate change and won a Nobel Peace Prize for his efforts.

Commenting on the candidates’ views on climate change, Gore said presumed Republican nominee John McCain should be complimented for showing “a willingness to debate some critical issues, including the climate crisis, that many Republicans have refused to discuss at all.”

Gore said that Obama “knows that we are too dependent on foreign oil and carbon fuel and has proposed a plan to create millions of good new jobs in renewable, green energy, conservation and efficiency.”

Connecticut Senator Joe Lieberman, Gore’s running mate in 2000, endorsed a candidate months ago. The Democrat turned Independent Lieberman has been supporting and campaigning with McCain.