China will not allow its carbon dioxide emissions per person to reach levels seen in the US, according to the minister in charge of climate policy.
Xie Zhenhua, vice chair of the National Development and Reform Commission, said that to let emissions rise that high would be a "disaster for the world".
Chinese per-capita emissions may reach US levels by 2017, a recent study said.
Mr Xie was speaking during a visit to the UK that explored co-operation on clean energy and climate issues.
It included signing a Memorandum of Understanding with UK Energy and Climate Secretary Chris Huhne on areas for joint research.
China's emissions have risen sharply in recent years due to rapid industrialisation, fuelled mainly by coal burning. In terms of national emissions, it has overtaken the US.
But because its population is so much bigger, its per-capita emissions are currently much lower - but rising fast.
An analysis released last month by the European Commission's Joint Research Centre (JRC) put China's annual emissions at 6.8 tonnes of carbon dioxide per person, compared to the US figure of 16.9 tonnes - although other analyses put the US figure higher, around 20 tonnes.
But the Chinese number has tripled since 1990, says the JRC - and could rise to US levels within six years.
However, Mr Xie, speaking to a group of UK parliamentarians, said China would not "follow the path of the US" and allow per-capita emissions to rise that high.
"We are making efforts to control greenhouse gas emissions and our carbon intensity is decreasing," he said.
"We want to reach the peak as soon as possible."
China's current five-year plan projects economic growth of about 40% from 2010 to 2015, but a 17% fall in carbon intensity - the CO2 output for each unit of GDP growth.
A longer-term goal is to boost energy efficiency by 40-45% from 2005 levels by 2020.
The minister emphasised that in a domestic context, these targets are legally binding.
If China does develop along these lines, its per-capita emissions will soon overtake those in several EU nations.
In fact the JRC analysis says it has already overtaken France, which uses nuclear reactors to generate 80% of its electricity, and Spain.
At some point, it will come under pressure internationally to begin to cut its emissions rather than just restraining their rise.
Asked whether that could happen soon after 2020, Mr Xie said it would depend on what level of economic development had been reached.
"China will make commitments that are appropriate for its development stage," he said.
"Since we have declared a low-carbon and green development path, China will follow this path."
Whether a Chinese peak after 2020 would be able to help constrain climate change within limits often regarded as "safe" is another question.
A study published over the weekend in the journal Nature Climate Change showed that if global emissions do not peak and begin to fall by 2020, keeping the global average temperature rise since pre-industrial times below 2C will be difficult.
Since the UN climate summit in Copenhagen two years ago, the political scene on climate change has shifted markedly, with members of established negotiating blocs reaching out to countries that have not traditionally been allies but which now share common interests.
This is one of the reasons why China and European countries are exploring the potential for collaboration in areas such as novel fuels.
Another is that western engineering expertise allied to Chinese manufacturing could result in "green" products at low price.
For the UK, part of the idea is to rebuild bridges that were singed, if not burned, after Copenhagen when Ed Miliband - then climate secretary and now leader of the opposition - blamed Chinese negotiators for scuppering the talks.
Mr Xie's visit was facilitated by Global Legislators Organisation for a Balanced Environment (Globe) International, the worldwide association of parliamentarians.
Lord (Michael) Jay, Globe's vice president, suggested it was vital to make progress at this year's UN summit in Durban, South Africa.
"We hold the planet in trust for future generations," he said.
"And that puts a lot of responsibility on our shoulders before and after Durban."
And Mr Xie suggested that Europe and China could work together to push things forward.
"Let's join hands to push the US to take action," he said.
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