Coal is an environmentalist’s bugbear. The use of coal to generate energy is the key reason the world is looking at a catastrophic future because of climate change. Recognising this, global civil society has given a rousing call for coal divestment, asking companies, universities and individuals to stop investment in coal thermal power plants. They want coal to go, renewables to be in. And in the interim, clean gas, also a fossil fuel, to be used as a “bridge fuel”. In this scenario any talk of “cleaning” coal to make it less damaging is untenable.