The threat from global warming, he reports, "Is very real. It is only a matter of time before the temperature of the surface of the Earth becomes uncomfortable warm. What can we do Well frankly, I don’t believe we’ll ever be able to supply our power needs by simple devices such as windmills. I think the restriction of emissions of greenhouse gases will require the building of nuclear power stations in many places. The single most important development would be if there were some agreement on world population, because global warming will depend intrinsically on how much energy is consumed."
"But one of the reasons why the human population is growing so fast -- it is unlikely to stop this side of eight billion is precisely because we opted out of natural selection."