I read last week that the main reason why London has experienced 40+ degree temperatures recently, as opposed to the 30 or so of the past, is that big cities create large amounts of energy in the form of personal usage, for transport, electrical appliances etc, and this energy use is increasing. And it suddenly occurred to me that perhaps what we should be worrying about with regard to climate change is actually increased production of energy, something which shows no signs of abating, in spite of much noise made about carbon. The timescale is also suggestive: the current warming has coincided with the much greater use of energy of every kind (beginning with steam) associated with the Industrial Revolution. Nothing like it has ever occurred before – though high concentrations of greenhouse gases certainly have in Earth’s distant past. Whatever the truth about the greenhouse effect causing climate change – a theory which has never really convinced me, I have to say, as readers of my va