Last week, the Asia-Pacific Partnership on Clean Development and Climate - a group of the world's largest coal producers and consumers collectively responsible for 48 percent of global greenhouse gas emissions - met in Sydney. Their action statement was more or less what you'd expect from a collection of coal-burning countries who want to muddy the waters on climate change: a commitment to the development of "clean coal" technology. This commitment was purely rhetorical, not being backed by any measures to spur the adoption of such technology, or even real funding to help develop it - and according to the Australian Bureau of Agricultural and Resource Economics, it would not meaningfully reduce emissions. And the reason for that is obvious: they're wedded to coal as an energy source. But as Tim Flannery points out in The Weather Makers: the History and Future Impact of Climate Change, coal is a problem in and of itself:
The efficiency with which power is generated by burning a fuel is also an important factor in determining how much CO2 is produced. Even using the most advanced methods (and most coal-fired power plants come nowhere near this), burning anthracite to generate electricity results in 67 per cent more CO2 emissions than does methane, while brown coal (which is younger, and has more moisture and impurities) produces 130 per cent more. From a climate change perspective, then, there's a world of difference between using gas or coal to power an economy.
The reason for this is simple energy density - a kilo of anthracite coal yields between 26 and 33 MegaJoules when burned. A kilo of natural gas yields more than 50. This means that coal is a far worse fuel greenhouse-wise than natural gas - and will be even if the "clean coal" dream comes true and we adopt combustion methods like gasification, which approach the efficiency of modern gas power plants. While more efficient coal plants are good, particularly in light of the pathetic 30 - 35 percent efficiencies they get at the moment (compared with 45 - 55 percent for gas), coal is the problem, and we would be better off moving away from it in favour of other fuels, rather than continuing to slowly bake ourselves by using it.