Belching petrol and diesel fumes may become history sooner than we think. But we need to keep an eye on who's out to capture our hydrogen future, warns Jim Motavalli.

CHINA'S auto industry is the fastest growing in the world. In 1996 there were fewer than 2 million private cars; by 2002 there were 16 million. Visitors to China used to talk about all the bicycles. Now they talk about all the cars - and the smoggy cities.

James Cannon, who heads Colorado-based Energy Futures and visits China often estimates: 'The Chinese automobile population could surpass the US numbers, more than 200 million, within 10 to 20 years. At the current pace, you have China quickly becoming a larger carbon dioxide ([CO.sub.2]) emitter than the US, which is now the world leader.'

However, China's cars won't necessarily be fossil-fuel driven or have internal-combustion engines - an embryonic hydrogen industry could save the country from the tyranny of the tailpipe.

'When I visited China as part of a hydrogen delegation in 1997, we were hard pressed to find more than just basic research into the chemical and physical properties of hydrogen,' Cannon says. 'But since that time China has made very rapid progress in building a wellco-ordinated national hydrogen program. There are several fuel-cell cars now, and plans for larger numbers.'

With the world choking on auto exhaust, the zero-emission fuel cell is increasingly seen as its green savior. Hydrogen fuel cells aren't exactly new. They were invented by Briton Sir William Robert Grove in the 19th century but were not used until the 1960s' Apollo and Gemini space missions.

Fuel cells can be compared to a car battery in that hydrogen and oxygen are combined to produce electricity. The cells are stackable flat plates, each one producing about one volt, the size of the stack determining the power output.

If pure hydrogen is used as fuel the only emission is clean water, with waste heat as a by-product.

Fuel cells could replace power plants to produce electricity on a large scale; and they could be miniaturized to replace batteries in computers and even watches. But the race to put them under the hood of a car generated the most fierce international competition, led by Japan, Germany and the US.

Japan won. Last February, Toyota presented its FCHV fuel-cell car (based on the Highlander) at the University of California, Irvine. The car had been 10 years in the making. 'This could be one of those historic moments,' said Toyota boss Jim Press, 'almost like the Wright Brothers taking off from Kit Hawk.' That might be stretching it a bit, but the FCHV is the first market-ready hydrogen fuel-cell car delivered to a customer. On the same day Honda unveiled plans to test five fuel-cell vehicles with cells built by Canada's Ballard Power Systems, the world's fuel-cell leader.

The University of California has since been putting into daily use Toyota's cars, which have a top speed of 96 miles per hour, a range of 185 miles on a tank of hydrogen gas and get an equivalent of 64 miles to the gallon.

US car manufacturer General Motors meanwhile has been developing a fuel-cell car with a more generous 300-mile capacity. General Motors has good friends in Washington, where hydrogen is the new buzz word since President George W Bush announced $1.2 billion in research funding in January. It's perhaps no accident that White House Chief of Staff Andrew Card is a former GM vicepresident, as well as the former president of the American Automobile Manufacturers Association. Now GM is declaring its intention to be 'the first auto maker to sell a million fuel-cell vehicles - profitably'.

Who could oppose that? Most environmentalists like fuel cells. But they don't want the promise of them to delay the delivery of fuel-efficient cars today.

Then there's Bush's fondness for the idea of producing hydrogen from nuclear power. Indeed, many see the need for large-scale hydrogen production as a way to jumpstart the moribund nuclear industry.

Hydrogen can be generated in a number of ways: locally using renewable energy or by using power from the large-scale, centralized oil and nuclear power industries.

'Nuclear-generated hydrogen is like a nicotine patch that causes cancer,' says Dan Becker, energy program director for the Sierra Club environmental group. The fossil-fuel and nuclear industries are already beginning to muscle in on hydrogen conferences and workshops. Shell Hydrogen is getting stuck in. It's installing hydrogen pumps at one of its Washington garages in conjunction with GM's plan to provide a fleet of six fuel-cell Zafira mini vans at $1m each for people to test drive.

If fossil fuels are used in the process of separating hydrogen from one ofits many sources -- water for example -- this will produce greenhouse gases and significant pollution. If extracted from natural gas through a process called steam reformation this will generate [CO.sub.2] as well.

Only through the use of renewable resources is the whole process emissions-free. Photovoltaics (PV), wind energy, hydro-electric power, geothermal and biomass could each be harnessed to produce the electricity needed to isolate hydrogen.