WRAPUP 2-G8 set to clash with poorer states on climate

(For more G8 summit stories, click on [G7/G8]) (Recasts, adds quotes)

* G8 set for climate change showdown with emerging nations

* Poor states unimpressed by G8 plan to curb greenhouse gases

* Two sides may clash over global trade as key talks loom

By Chisa Fujioka and Jeremy Pelofsky

TOYAKO, Japan, July 9 (Reuters) - Big emerging economies including China looked set on Wednesday to clash with G8 rich countries over how to fight global warming.

Papering over deep differences, the G8 said on Tuesday they would work toward a target of at least halving global greenhouse gas emissions by 2050 but emphasised they would not be able to do it alone.

The Group of Eight industrial nations want the leaders of eight fast-growing countries to adopt a "shared vision" of tackling global warming in U.N. negotiations due to conclude in Copenhagen in December 2009.

The U.N.-led talks aim to create a new framework for when the Kyoto Protocol expires in 2012.

"It's the stalemate we've had for a while," said Kim Carstensen, director of environmental group WWF's global climate initiative. "Given the lack of willingness to move forward, particularly by the U.S., it hasn't been possible to break that.

Critics said the G8 agreement was a timid advance on last year's summit commitment in Heiligendamm, Germany, to seriously consider the 2050 goal of halving emissions by mid-century.

"This is a complete failure of responsibility. They haven't moved forward at all. They've ducked the responsibility of adopting clear mid-term targets and even the 2050 target is not a single thing more than what we got in Heiligendamm," said Daniel Mittler, Greenpeace International's political adviser.

WWF called the G8's stance "pathetic".

The G8 summit on the northern Japanese island of Hokkaido brings together the leaders of Japan, Britain, Canada, Germany, France, Italy, Russia and the United States.

China, India, South Africa, Mexico and Brazil called on rich nations on Tuesday to slash their carbon emissions by 80-95 percent below 1990 levels by 2050, and make cuts of 25-40 percent by 2020.

Leaders of these large emerging nations joined the G8 on the last day of its three-day summit in a so-called Major Economies Meeting that Australia, Indonesia and South Korea also attended.