London Canada and Japan were blocking a possible deal on climate change at the Copenhagen summit, Sir David King, the former Chief Scientific Adviser, warned yesterday.

Speaking at the World Conference of Science Journalists, Sir David said that the two countries had stepped into the breach left by the Bush Administration, which had strongly resisted cutting CO2 emissions.

“Copenhagen is faltering at the moment,” said Sir David. “The Americans are now fully engaged. But several countries are blocking the process.”

Governments previously were able to hide behind the US’s intransigence on climate change, he said, but the pro-climate policies being launched by the Obama administration means this is no longer possible. “The time has come for people to reveal their cards,” he told delegates.

Gordon Brown has said he will be pushing for an agreement at Copenhagen in December which pegs global warming to 2 degrees celsius above pre-industrial levels, a widely agreed target among climate scientists. He has committed to cut emissions in the UK by 80 per cent, compared to 1990 levels, by 2050.

Canada’s position is widely believed to be driven by its powerful industry lobby, which is keen to exploit oil reserves in the country’s tar sands. “These people are very outspoken, aggressive lobbyists,” said Dr Robert Falkner, a specialist in international relations at the London School of Economics. “They are gung-ho about rising oil prices and want to exploit that.”

The low profile of science in the Canadian and Japanese governments — both countries have recently scrapped the role of chief scientist — is also contributing to their stances, according to Sir David.

A weak agreement at Copenhagen, which committed countries to unambitious cuts, would be worse than no agreement, Sir David said. He argued that in this case, a better alternative would be an ambitious bilateral agreement between China and the US. “If you had the Chinese premier Wen Jiabao and Obama on the same stage, together with the EU’s position, this would be a strong move in the right direction,” he said.

In his plenary address, Sir David also announced the World Summit on Enterprise and Environment, which will be held in Oxford from 5-7 July, and is jointly hosted by The Times and the Smith School of Enterprise and Environment. The summit will be attended by several heads of state, Al Gore and Ken Livingstone, the former Mayor of London.

Canada and Japan were also singled out yesterday in the “Climate Scorecard” assessment of the Group of Eight nations prepared for the G8 summit in L'Aquila, Italy, next week. Canada was ranked worst, both in terms of its emissions and on planned measures to reduce them, according to the study compiled by the environmental group WWF and the German insurance group Allianz.

Canada agreed under the Kyoto Protocol to reduce CO2 emissions to 6 per cent below 1990 levels by 2012. But 2007 figures, the latest available, show its emissions were 26.2 per cent higher than in 1990. “They have increasing emissions and absolutely no policies in place,” said Nicholai Tewes, a spokesman for Allianz and one of the report’s authors.

Japan, ranked fifth, has relatively low emissions per capita. But it was faulted for reneging on targets that it had previously set itself.

The US, which was placed last in the 2008 rankings, moves up a place. Although it still accounts for half the total emissions of G8 countries, it was praised for the rapid turnaround in policy. “Obama has done more for climate change in the last six months than the US did in the last three decades,” said Mr Tewes.

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