Oil and other fossil fuel depletion
Many fear that the world is quickly using up the vast but finite amount of fossil fuels.
Some fear we may have already peaked in fossil fuel extraction and production.
So much of the world relies on oil, for example, that of there has been a peak, or if a peak is imminent, or even if a peak is some way off, it is surely environmentally, geopolitically and economically sensible to be efficient in use and invest in alternatives.