Just speculation, but... What is the lead time in developing new fossil sources? What is the time to profitability? How long will there be political will to

Just speculation, but... What is the lead time in developing new fossil sources? What is the time to profitability? How long will there be political will to greenlight new developments? Depending on those we might run out of the option to increase production of fossil fuels in less time than we have physical reserves for.