I came across the following shocking statement in my Economist magazine this week (28 July): ‘America uses more energy for air conditioning than Africa uses for everything.’ One of the health challenges of traversing America in a heat wave is avoiding catching colds from all the changes in temperature. In every building and on every train where we have slept we have had to turn the air conditioning down (or is that up?) or off. I have blogged previously about the extraordinarily long coal trains that growl their way through the Rockies, pulled and pushed by massive diesel locomotives. And yet this is the America of the wonderful national parks and a strong environmental awareness. One of the many paradoxes of America is its almost cavalier attitude to energy use, mainly seen as an infinite resource, and to the environment. This was summed up for me by something the volunteer guide in the observation car on the train to San Francisco said. She had described all sorts of wonders of nature about us and then got on to the 1969 Santa Barabara oil spill. This was, she said, for a long time the ‘biggest oil spill that ever happened in the world’. She said it almost as though she was proud.