The most critical processes for human success - population growth - is an exponential process. Pretty much all of it happened in the age of fossil fuels. We have 200 years (out of 200,000 of human history according to Wikipedia) of experience with global populations >1 billion and we are currently cruising at about 8 billion souls on the planet. All of that 200 years is in the context of freely available and rapidly growing utilisation of fossil fuels to power the logistics networks enabling the growth.
History doesn't show us being adaptable, history shows if something happens to the solid/liquid carbon supply around 7/8 of us are expected to die. And we can statistically all-but guarantee something will sooner or later over a long period.
Our major reason to be hopeful is our history isn't a guide and that something other than oil really makes strides. Maybe nuclear, maybe renewables.
