The G-8 countries -- the United States, Japan, Russia, Germany, France, Britain, Canada and Italy -- also called on all major economies to join in the effort to stem the potentially dangerous rise in world temperatures.
"The G-8 nations came to a mutual recognition that this target -- cutting global emissions by at least 50 percent by 2050 -- should be a global target," said Japanese Prime Minister Yasuo Fukuda, who announced the endorsement.
The G-8 last year at a summit in Germany pledged to consider the 2050 target, and this year's Japanese hosts had hoped to solidify that commitment at the meeting in Toyako, northern Japan.
The G-8 has been under pressure to secure commitments by wealthy nations to push forward stalled U.N.-led talks on forging a new accord to battle global warming by the end of next year. Tuesday's statement, however, addressed world emissions rather than just those produced by wealthy countries.