At this week's Group of Eight summit, Prime Minister Junichiro Koizumi will propose easing conditions on Kyoto Protocol projects to make emissions credits easier for Japan and other nations to get, government sources said.
Preventing global warming is one of the top issues on the agenda for the G-8 summit from Wednesday to Friday in Gleneagles, Scotland, along with addressing poverty, especially in Africa.
Japan will also announce its plan to double official development assistance to Africa over the next three years.

Under the Kyoto Protocol's Clean Development Mechanism (CDM), developed nations that carry out emissions-cutting projects in developing nations are allowed to obtain credits that can be assigned to their own reduction goals.
When a business builds a wind power generation plant in a developing nation, for example, it gets credits for part of the reductions.
Under the protocol, which took effect in February, Japan is required to reduce its annual greenhouse gas emissions during 2008-2012 by 6 percent from 1990 levels.
The target is thought almost impossible to achieve with domestic reductions alone.
A Cabinet plan adopted in April on how to meet the goals is counting on CDM projects for a 1.2 percent reduction.
But only seven projects have so far been officially registered as CDM projects globally.
To register, a project must be approved by the governments of both the developed and developing nations, and then get accreditation for its effectiveness by a third-party organization.
Next comes screening by the CDM executive board of the United Nations where, sources said, the justification behind the project is questioned.
Concerned that these hurdles may discourage businesses, the government has decided to ask that CDM conditions be eased, according to the sources.
To that end, it set up a panel in March to discuss CDMs with China, Brazil and other nations.
Koizumi will also propose at the summit the formation of a system for integrating global observation data to better prepare for disasters such as earthquakes and tsunami.
The new data system would supplement a global monitoring system that the Earth Observation Summit decided in February to build by 2015. The data system aims at a long-term forecast, the sources said.
Meanwhile, Koizumi will likely have only two bilateral talks-with British Prime Minister Tony Blair and Russian President Vladimir Putin-on the sidelines of the summit.
Since 1997, Japanese prime ministers have had bilateral summits with three to six leaders at each summit, except for two each in 2001 and 2003.
Koizumi is apparently not keen to meet with U.S. President George W. Bush because of stalled issues, including the U.S. beef import ban and U.N. reform, the sources said.