The 2016 Olympic Games could be the last due to the threat of global warming, Tokyo governor Shintaro Ishihara said in Copenhagen on Tuesday. 

Speaking to reporters at a press event, Ishihara explained his belief that the urgent need to address global warming may hamper future events because of their sheer size.

"It could be that the 2016 Games are the last Olympics in the history of mankind," Ishihara said.

Tokyo is among the cities bidding to host the 2016 Games along with Chicago, Rio de Janeiro and Madrid. The International Olympic Committee will elect the winning candidate on Oct. 2 in Copenhagen, where world leaders will also meet this December to hammer out a replacement for the Kyoto Protocol.

Ishihara implied that Tokyo is best prepared to steer the Olympics toward being as green as possible, with proposals for an Olympic stadium that would be the first to be fully powered by renewable energy.

"Global warming is getting worse. We have to come up with measures without which Olympic Games could not last long. Scientists have said we have passed the point of no return,” he said. "Tokyo is prepared to do everything to create the best conditions for the athletes.”

Ishihara faces stiff competition in the bid to host the Games, as U.S. First Lady Michelle Obama and billionaire mogul Oprah descend upon Copenhagen to push the case for Chicago.