The two Republican leaders took an aerial tour of the nation's busiest port complex by helicopter, flying over the Gerald Desmond Bridge, Long Beach (710) Freeway and several container terminals before stopping by the Maersk Sealand property on Terminal Island.
There, the veteran Republican senator from Arizona said addressing climate change is one of the world's most pressing issues.
"It's now widely acknowledged to be a great threat to our planet, our children and our grandchildren," McCain said. "Time is not on our side, we must act."
He also used the opportunity to blast the Bush administration as unresponsive to global warming.
"This administration's record on global warming is terrible," McCain said. "I've held hearings for years and got no cooperation from the administration on this issue."
He later said he was encouraged by the president's recent acknowledgment of the issue, but said more needed to be done.
"The debate on climate change should be over," McCain said. "California's actions ... send a message to Washington that they expect us to act at the federal level."