Tokyo governor Shintaro Ishihara warned on Wednesday the 2016 Olympics could be the last Games, with global warming an immediate threat to mankind.
Tokyo is bidding to host the 2016 summer Olympics with Chicago , Rio de Janeiro and Madrid also in the running. The International Olympic Committee will elect the winning candidate during its session on October 2 in the Danish capital.
"It could be that the 2016 Games are the last Olympics in the history of mankind," Ishihara told reporters at a Tokyo 2016 press event ahead of the vote.
"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," said Ishihara.
Tokyo has put considerable emphasis on staging a green Games with the planned Olympic stadium the first to be fully powered by renewable energy, including solar power.