"None of the eight leading industrial nations have taken sufficient measures needed to be considered in line with the target to limit a worldwide increase in temperatures to 2 degrees centigrade," said Niklas Hoehne, the author of the study done by ECOFYS research group for WWF and Allianz.

They said leaders of the Group of Eight countries -- which have emitted 62 percent of the CO2 in atmosphere -- have talked about cutting emissions but largely failed to follow through.

The G8 leaders from the United States, Japan, Germany, Britain, France, Italy, Canada and Russia will meet in the Japanese resort of Hokkaido for their annual summit next week, where climate change is due to be a top issue on their agenda.

At last year's summit in Germany they agreed to seriously consider a goal of halving global emissions by 2050.

The scorecard offers grim reading, showing all eight countries have failed to match their words with deeds.

US, CANADA, RUSSIA FAIL TEST

The study examined the climate performance by federal governments in implementing measures to reduce their emissions. Also included are performances in energy efficiency, renewables and carbon market development.

The G8 Climate scorecard ranked the United States, Canada and Russia at the bottom, saying they had "failed the test".

"The United States scores the worst of all G8 countries, being the highest emitter with the highest per capita emissions and an increasing trend in total emissions," the report said, giving the US "red" ratings in 11 of the 12 categories.

"Canada is second with a very high per capita emissions and a steadily increasing trend in total emissions," it said.

"Russia ranks a bit better due to declining emissions in the early 1990s ... but since 1999 emissions are increasing steadily and there is hardly any policy in place to curb emissions."

The study also gave Italy and Japan "red" overall ratings. Emissions from both are well above their Kyoto Protocol targets and there are few national measures in place to cut emissions.

Britain, France and Germany were put at the top of the scorecard in that order. But all were given only a "yellow" overall rating, falling short of "green" for top scores.

Britain was lauded for its emissions being below their Kyoto targets but criticised for deriving only a small share of its power from renewable sources.

France was also lauded for getting its emissions under the Kyoto target and got plus points for its low emission rates, due to the high share of nuclear energy. But it was criticised for projections that emissions will rise if no policy changes made.

Germany, which sees itself as a leader in the fight against climate change, was ranked third. It was faulted for high emissions from coal-powered plants and transport. Its decline in emissions is due mainly to collapse of east German industry.

(Editing by Mary Gabriel)