Nov. 5 (Bloomberg) -- Japan's greenhouse gas emissions rose 6.4 percent in the year ended March from 1990 levels, forcing the government to quicken measures to ensure the country meets its Kyoto Protocol target.

Japan emitted 1.341 billion metric tons of gases including carbon dioxide and methane in fiscal 2006, according to a preliminary report today by the environment ministry. While the figure was 1.3 percent lower than a year earlier, it fell behind the nation's emissions reduction goal under the Kyoto Protocol.

Under the 1997 United Nations climate-change treaty, Japan pledged to cut annual average emissions by 6 percent starting April 2008 from levels in 1990. Prime Minister Yasuo Fukuda's administration is meeting to decide on the implementation of measures such as the start of a carbon tax on fossil fuel use and the creation of emission trade.

Emissions of carbon dioxide fell 1.3 percent from the previous fiscal year. Still, the figure was 11.4 percent higher compared with the 1990 level, according to the report.

The nation's carbon dioxide emissions reached 1.275 billion tons last fiscal year. Efforts by Japan's power utilities and steelmakers including Tokyo Electric Power Co. and Nippon Steel Corp. to boost purchases of carbon-emission credits have failed to bring down emissions levels.

Factories and office-building owners have also switched from oil to cleaner-burning fuel for their in-house power generators and boilers.

Household Emissions

Carbon dioxide emissions in households fell 4.4 percent from a year earlier, the report shows, citing a decline in pollution caused by increased use of air-conditioners and the burning of kerosene, Japan's main heating fuel. The figure was 30.4 percent higher compared with levels in 1990.

Output of carbon dioxide from transport-related sources such as cars and trucks decreased 0.9 percent from the previous year. The emissions were 17 percent higher from the 1990 level. Japan's households have accelerated a shift to fuel-efficient mini cars on growing environment concerns, together with surging gasoline prices.

The per-capita emission of carbon dioxide declined to 9.98 tons in last fiscal year, the first time in five years that the figure has fallen below a 10-ton level, the report said.

Under the Kyoto treaty's mechanism, polluters in developed nations can buy credit from projects that cut harmful emissions in developing countries.

To contact the reporter on this story: Shigeru Sato in Tokyo at ssato10@bloomberg.net.

Last Updated: November 5, 2007 03:50 EST