Japan's cabinet on Tuesday adopted a plan to slash carbon emissions up to 80 percent by 2050 by starting carbon trading and stepping up research on carbon-capture technologies.

"Japan must continue showing leadership on the issue of environment," Prime Minister Yasuo Fukuda told the cabinet meeting. "To lead the world, Japan must take the initiative by achieving a low-carbon society."

Japanese industry leaders, particularly steelmakers and the power industry, have strongly opposed Fukuda's plan, arguing it would hurt an already weak economy.

Environmentalists in turn have said the plan is not ambitious enough as it does not set more immediate targets for the coming decade, which many scientists say is crucial to stopping the planet from heating up.

Fukuda unveiled the plan before hosting this month's gathering of the Group of Eight rich nations, where climate change was a key topic.

It establishes an experimental "cap-and-trade" system, which requires firms to slash emissions and gives them an economic incentive by trading credits.

Under the plan adopted Tuesday, Japan will start carbon trading, which has developed into a rapidly growing market in the European Union, on an experimental basis later this year with an eye to fully introducing it later.

The plan also calls for research on carbon-capture technology, which contains greenhouse gases emitted by power plants and factories and stores them underground, to put in place a nationwide system by 2020.

Japan will also increase the use of solar power tenfold by 2020 and 40 times more by 2030, while forging ahead with plans to build nine more nuclear reactors by March 2018.

Leaders of the G8 -- Britain, Canada, France, Germany, Italy, Japan, Russia and the United States -- agreed at their summit to cut carbon emissions by at least 50 percent by 2050.

The G8 called on the developing world to take part, a key demand of the United States, the only major industrial nation to reject the Kyoto Protocol, whose obligations to cut emissions expire at the end of 2012.