"China is an enormously important piece of the jigsaw," he told Reuters on Friday, his second day in the job.

China is building a large coal-fired power station every four days on average and has embarked on a major nuclear power plant construction campaign to fuel its booming economy.

It is also building infrastructure at a faster rate than ever before in human history and has become the second-biggest source of carbon emissions in the world after the United States.

"The point about China is not what it is emitting at the moment, it is the rate of build of infrastructure and the rate of deployment of capital," Ashton said. "That means they are locking in a future emissions profile."

The technology to capture and store carbon emissions from coal burned to generate electricity -- crucial because coal is in ample supply worldwide -- is largely untried.

Demand for currently expensive renewables like wind turbines and large solar power arrays is too small to bring down the costs of production.

China could be just the place to solve many of these problems, Ashton said. "If you want to bring technologies that are near maturity into maturity as rapidly as possible and as cheaply as possible, the best place to do that is somewhere that is deploying capital rapidly -- namely China."

"Climate change needs to be seen not as an economic threat, but an economic opportunity," he said.

"I am interested in results -- how do we get where we need to be," Ashton said. "The more I do of this the more I believe it is possible to achieve the alignments we need."

Ashton sees no easy answer to the problem of human-induced climate change.