The European Union and green groups piled pressure on the United States on Monday to agree to a target to halve global greenhouse gas emissions by mid-century and back the need for rich countries to set 2020 goals as well.
Climate change is high on the agenda for the G8 nations meeting at a luxury hotel on the northern Japanese island of Hokkaido from Monday to Wednesday. But green groups fear the summit will end in failure by not committing to a pledge to slash emissions by 2050.
Leaders from China, India, Brazil, Australia and other big carbon polluters will also meet G8 members during a separate gathering of what is known as the Major Economies Meeting.
"Let's agree a clear-cut 50 percent reduction by 2050. And let's agree on the principle of a midterm (target)," European Commission President Jose Manuel Barroso told reporters in Hokkaido on Monday, adding the meeting would be a success if these points were agreed by the G8.
"If we agree among ourselves (in the G8), then we are in a much better position for discussions with our Chinese partners and others."
China and India, whose rapidly growing economies produce about a quarter of mankind's greenhouse gas emissions, have refused to commit to fixed targets to curb emissions unless rich nations, and particularly the United States, do so.
Developing nations also want more financial aid and transfer of clean energy technology and a commitment from rich nations to a midterm target to cut emissions. The G8 emits about 40 percent of mankind's greenhouse gas pollution, about half of that alone coming from the United States.
President George W. Bush has refused to back any fixed numerical targets to cut emissions unless developing nations agree to binding commitments to curb their carbon pollution.
Green groups have low expectations of an about-face from the Bush administration at this year's G8 and say the bloc hasn't made progress in fighting climate change over the past year.
At the G8 summit in Germany last year, leaders agreed to "seriously consider" cuts of "at least" 50 percent by 2050.
