KEY POINTS:
Should New Zealand worry as China and the United States greatly increase their capacity to produce electricity? It sounds a silly question. But it should not be treated that way.
More and more coal around the world is being burned in power plants to generate electricity. This threatens to have the biggest single impact on the potentially catastrophic rise in global temperatures caused by emissions of gases heating the earth's atmosphere.
Coal is increasingly popular as an industrial-scale fuel because it is abundant, widely distributed, and cheaper than oil, natural gas or renewable energy sources like wind power.
China and the US have vast reserves of coal compared with their limited supplies of domestic oil and gas.
Since electricity demand is soaring, both countries are adding coal-fired plants like crazy. Over 150 new ones are planned or being built in the US.
In China, some 550 such plants are under construction.
On the positive side, this gives China and the US another productive area in which to co-operate.
But on the negative side, it will hugely increase global warming gas emissions by the world's two biggest polluters and hasten disruptive climate change - unless technology is harnessed to cut the release of CO2, the main greenhouse gas.
CO2 - produced when fossil fuels like coal are burned - accounts for 80 per cent of the world's man-made emissions of global warming gases.
Many scientists agree these emissions of CO2 and other greenhouse gases could cause severe environmental damage.
If they are correct, even countries like New Zealand that are far away from the main sources of CO2 releases will suffer.
In New Zealand's case, the consequences are likely to include less snow and retreating glaciers that will reduce the amount of water coming down from the mountains in spring.
As a result, the levels of dams that feed water into hydro-electricity generators will fall and New Zealand will have to turn increasingly to other sources of energy, possibly coal, to produce power.
Worldwide, electricity generation - mainly from burning coal - contributes 40 per cent of CO2 emissions.
In China, coal-fired plants produce 75 per cent of total electricity supply; in the US, around 50 per cent.
Why do these statistics matter? Because China and the US together contribute nearly 40 per cent of global CO2 releases. They are by far the two biggest polluters. Last year, the US contributed 21.2 per cent and China 18.5 per cent of the 28 billion tons spewed into the atmosphere.
The International Energy Agency reported last month that China will surpass the US in 2009 as the biggest emitter of CO2. The forecast date - nearly a decade ahead of previous predictions - highlights the unexpected speed at which China is emerging as the top contributor to global warming.
China has a lot of scope to improve energy efficiency and conservation.
Japan, with an economy about three times larger than China's, produced one third less CO2 emissions than its neighbour last year.
Japan can do this because it generates nearly all its electricity from nuclear power or gas-fired plants. The former produce almost no CO2 emissions.
Gas, too, is relatively clean. Coal-fired plants produce roughly twice as much CO2 per unit of electricity generated than those that run on gas.
China has begun requiring power companies to invest in bigger, more efficient coal-fired plants.
The US is well ahead of China in developing cleaner-burning coal plants. Modern power plants use technology to remove much of the soot and noxious chemicals released when coal is burned. These include oxides of sulphur and nitrogen.
But the big breakthrough for both China and the US in cutting CO2 releases will only come with carbon capture.
Most plans for CO2 storage involve liquefying it and pumping it underground into former oil reserves, gas fields or coal mines. This is an energy-intensive and thus expensive process. And in how many places are such big underground reservoirs conveniently located close to actual or potential power plant sites?
Experimental clean coal power plants that would bury CO2 are under way in China, the US and other countries. But to be commercially viable, the cost must be brought down and new regulations imposed, such as long-term caps or taxes on CO2 emissions.
Neither China nor the US seem prepared yet to do this, fearing it would undermine economic growth. And whatever measures they agree would have to be adopted by other major polluters as well.
The Kyoto Protocol, the sole international emissions policy in force, requires a 5 per cent cut in CO2 releases from 1990 levels by only 35 countries by 2012.
It does not bind three of the five biggest polluters. The US pulled out, and China and India were exempted along with other developing countries.
Meanwhile, global carbon emissions, which rose nearly 3 per cent last year, have risen over 25 per cent from 1990 levels. We are fiddling while the world burns.
* Michael Richardson, a former Asia editor of the International Herald Tribune, researches energy and security at the Institute of South East Asian Studies.
