Some people hold that the threat of climate change is so great that we need to fundamentally change the way we produce and use energy. What’s your response to this view?
Climate change is a natural phenomenon. Climate keeps changing all the time. The fact that climate changes is not in itself a threat, because, obviously, in the past human beings have adapted to all kinds of climate changes.
The argument is that there’s a new cause for climate change, which is human beings. And that the dimensions of this change might exceed what is natural or normal.
Well, there’s no question in my mind that humanity is able to affect climate on a local scale. We all know that cities are warmer than the suburbs or surrounding countryside. So there’s clear indication that human beings, in producing energy, in just living, generate heat. We’re not going to go back to living without energy.
Whether or not human beings can produce a global climate change is an important question. This question is not at all settled. It can only be settled by actual measurements, data. And the data are ambiguous. For example, the data show that the climate warmed between 1900 and 1940, long before humanity used much energy. But then the climate cooled between 1940 and 1975. Then it warmed again for a very short period of time, for about five years. But since 1979, our best measurements show that the climate has been cooling just slightly. Certainly, it has not been warming.