"The level of seriousness on this is absolutely undoubted," he said in an interview with China Daily yesterday.
"I think the difference today from, say, a few years ago, is that there's enormous goodwill and determination," he said.
Blair, 56, was speaking in Beijing on behalf of the Climate Group, a non-governmental international organization seeking to secure a global deal on the environment backed by both the United States and China.
Blair's visit came days after government research groups published a report that said China's emissions of carbon will likely peak in 2030.
China is the world's second-biggest energy user after the US and is one of the top two emitters of greenhouse gases, along with the United States.
Blair was accompanied by the Chinese actress Li Bingbing, who has been appointed an ambassador for the Asia Pacific region by the Climate Group. She announced that she had bought 20,000 trees to offset the 32,200 kilos of carbon dioxide created by the 380,000-plus km she expects to fly this year.
In the interview, Blair used the Chinese word weiji, or crisis and opportunity, to describe the current situation.
He said the world is in crisis over climate change but there are opportunities to be grasped to overcome it.
"It is a crisis, but it's also an opportunity to restructure our economies, to invest, as countries are investing. So, let us invest in clean technology for the future," he said.
"Here in China, the Chinese leadership is absolutely committed to tackling this issue. It's become a major part of its domestic policy. The Americans are now fully committed to it. The Europeans (too).
"So yes, it's going to be a big challenge but, on the other hand, I think the desire is there to reach an agreement at Copenhagen in a way it wasn't there 12 years ago at Kyoto."
Industrialized nations are pushing for commitments to binding cuts in carbon emissions, putting countries such as Germany, Japan and the UK at loggerheads with China and India months before a new global accord on climate change is set to be negotiated in Copenhagen in December. The accord will replace the United Nations protocol signed in Kyoto in 1997.
Blair said: "For the political leaders, they have challenges on every side in relation to this. It's difficult. It's tough. President Obama is under intense pressure in the US over the issue.
"The Chinese leadership, of course, has got to balance commitment to action on climate change with economic growth.
"These are not easy questions. But what I would say is, the level of determination is bigger than it's ever been before. And I really believe this time that China and America need not be in collision on this issue.
"They can cooperate to find a common solution and I think that is their shared collective will," he said.
Video: Cong Fangjun,Lou Yi
Photo: Wu Chuanjing
Editor: Cong Fangjun
Story: Mark Hughes