Extracting oil from the tar sands is a nasty, polluting, energy-intensive business.
When it comes to energy, cost isn't everything - but it's a lot. Everybody wants cheap power.
When it comes to climate and energy, Gates is a radical consumerist. In his view, energy consumption is good - it just needs to be clean energy.
In the world of energy politics, the sudden vanishing of the word 'coal' is a remarkable and unprecedented event.
