The disparity in energy use between different countries is linked of course to their level of economic development. But that's not the only factor. Both Germany and the USA are highly industrialized nations. But in the United States, much more energy is being consumed by each person. In part that's because it's a bigger country, so people travel more. But it's also down to attitudes. American energy consumption could easily be reduced if greater priority was given to energy efficiency. Actually, I'm confident that efforts will be made in this direction, particularly by industry — cleaner fuels, cleaner industrial processes and so on — because the evidence for climate change is now so strong. The big question is: will developing countries do the same? Transport's a big issue — air travel in particular. People in developing countries have been restricted by the cost up to now. But as they get richer and air travel becomes cheaper, its impact on energy consumption is bound to grow. The statistics for energy use in the home show that the main area which needs to be addressed is heating and cooling. The solution is relatively cheap and simple. It just means homes being insulated properly. People complain about their energy bills, but it's pretty clear to me.