KEY POINTS:
China is rapidly emerging as a key player in climate change politics, both as a major cause of the greenhouse gas emissions that are warming the planet and as a partner in international efforts to curb emissions.
China's role as a leading contributor to global warming was underscored by the recent spurt in growth recorded by its already supercharged economy.
The unexpected rise of just over 11 per cent in gross domestic product for the first quarter means that the world's most populous nation could overtake the United States as the largest emitter of greenhouse gases this year or next - at least a year earlier than the International Energy Agency predicted five months ago.
China's rise as a dirty power is impelling it to take more effective action to cut emissions.
Its own position on global warming has evolved considerably in the past few months. Previously, it had adopted a stonewall posture, blaming the US, Europe, Japan and other advanced economies for the mess and asserting that they should be responsible for cleaning it up.
China can argue that while it may be an economic powerhouse now, it has contributed less than 8 per cent of the total emissions of carbon dioxide from energy use since 1850, while America is responsible for 29 per cent and Western Europe for 27 per cent.
Carbon dioxide, or CO2, is produced by burning fossil fuels such as coal, oil and gas for heat, power and transport. Many scientists say it is the main contributor to global warming.
China can also argue that although it may soon overtake the US as the top emitter of CO2, largely because it gets 70 per cent of its energy from coal, the highest carbon-emitting fuel, its comparative emissions for the average person are far below those of wealthy countries. UN figures show that the average US citizen is responsible for at least 20 metric tonnes of CO2 pollution each year, compared with China's 3.2 tonnes and the world average of 3.7.
Beijing has also made the point that much of the growth in China's emissions is to produce goods exported to the West.
Yet the scale and scope of China's pollution far outpaces that of the US and Europe during their industrial revolutions. If it continues unchecked - and other big emerging economies like India and Brazil follow a similar high-carbon growth path - the impact on the health of the planet could be catastrophic.
The Beijing Government acknowledges that it has a responsibility to control emissions.
China and Japan agreed this month to take part in negotiations on a framework for limiting global warming after 2012.
This shift in position, following a meeting in Tokyo between Chinese Premier Wen Jiabao and his Japanese counterpart, Shinzo Abe, was overshadowed by other matters in the sensitive bilateral relationship between Asia's economic giants.
But it is a important step forward in tackling global warming because it shows that China is ready to engage in future talks.
The existing accord, the Kyoto Protocol, signed in Japan a decade ago after two years of negotiations, binds only 35 developed nations and the European Community. Their aim is to have greenhouse gas emissions 5 per cent below 1990 levels by 2012. The US and Australia refused to ratify the deal, arguing that it would damage their economies and that major carbon polluters in the developing world must be part of any effective global pact.
China is shifting ground because it realises that it must be a player if it wants to shape any post-2012 pact.
Chinese scientists warn that China will suffer badly from the adverse consequences of a warmer planet. Its own water and air pollution are already among the world's worst. Large parts of the country are short of water and this will become even more serious with the increased melting of glaciers on the Qinghai-Tibetan plateau - a vital source of fresh water for about 750 million people in China, India and other parts of Asia.
The Chinese Government's first national assessment of climate change warned bluntly that economic growth could be undermined. China's top climate change officials have said that a national plan on global warming, expected soon, will include policies for cutting greenhouse gas emissions.
China, like the US, Europe and many other countries, has a poor record in making cuts and applying policies that would be economically and politically painful.
As encouragement, Australia, Japan, Europe and the US have offered substantial aid and technical assistance to China.
The first pointer to whether the big polluters will do any better in future will come in June at a meeting of the Group of 8 advanced economies plus Russia, chaired by Germany.
China and four other big emerging economies will also attend and climate change will be a key issue.
* Michael Richardson, former Asia editor of the International Herald Tribune, is an energy specialist at the Institute of Southeast Asian Studies in Singapore.