Guardian: The government has finally come up with a clear policy about the sort of power stations it wants to see built: it wants coal and it wants it to be at least 20% cleaner than would be otherwise. This won’t be enough for deep green environmentalists but it is nevertheless a significant step forward from where we are today. Before today the mantra had been “let the market decide” but today’s announcement admits that we can’t rely on markets alone to tackle climate change or to stop us …