That doesn't happen so much if people reduce fossil -
fuel demand over the next few decades via efficiency and
substitution of other energy sources,
which doesn't happen overnight.
Consider a case study of
substitution offered by some of the Breakthrough Institute scholars who signed the Ecomodernist Manifesto: the replacement of whale oil by
fuels such as kerosene,
which, they argue, helped spare many species of whales from extinction at the harpoons of the whalers in the nineteenth century.