Former US vice president Mr Al Gore scoffed at President George W. Bush's plan to send astronauts to the moon and Mars and said Mr Bush was a "moral coward" for ignoring global environmental threats.
Speaking at an event sponsored by political advocacy groups MoveOn.org and Environment2004, Mr Gore said Mr Bush's record on the environment routinely puts the wishes of the coal, oil, utility and mining industries ahead of public interests.
"Instead of spending enormous sums of money on an unimaginative and retread effort to make a tiny portion of the moon habitable for a handful of people, we should focus instead on a massive effort to ensure that the Earth is habitable for future generations," Mr Gore said to a cheering Manhattan crowd.
The speech is one of a series Mr Gore, who served two terms as vice president under President Bill Clinton, has made criticizing Mr Bush's handling of the war in Iraq, the economy, and other issues. Mr Gore lost to Mr Bush in the 2000 election after winning the popular vote and has ruled out a rematch in 2004.
Yesterday, Mr Bush announced plans to send humans back to the moon as early as 2015 and eventually to Mars - an initiative critics derided as motivated by election-year politics that could cost hundreds of billions of dollars.