New Scientist: Never mind the downturn, a green economic revolution must be launched within months, one of the world’s top economists has told New Scientist. “You do hear voices saying now is not the moment,” says Nicholas Stern, former head of the World Bank, in an exclusive interview. “Now is precisely the moment to make the change” to a low-carbon economy. Stern believes low-carbon technologies have the potential to bring nations out of the recession and fuel economic growth that will be …