Earth will be way different. Hot in the northern latitudes, inhospitable the closer you get the equator. Humanity has proven its ability to stubbornly survive even in some of the harshest environments known to man — so I think humanity will persist but not in the same way we do today with 8+ billion people on the planet.

Modern civilization will collapse to a point where nature effectively forces our hand to stop releasing carbon into the atmosphere but not until the damage to our ecosystem is done.

If our electronic data survives we will have a pretty good idea of what humanity in the past has done to make much of the planet so inhospitable. Maybe humans will learn from it… maybe they won’t. Maybe this data will be purposefully hidden by the powers-that-be.

If we don’t have any data (or if we have an oppressive authority that obfuscates this data), I suspect that the story of “how it all disappeared” will be warped and twisted to the point where we may just have a new mythological story of origin that we pass to each generation. Climate change will just become a story of how the Gods became angry with humanity and extinguished most of life on earth as punishment for whatever made-up reason suits the new civilization’s ruling authority best. Most likely that reason will center around a dire warning to prevent overpopulation.

Regardless, evidence of our past civilization may be relegated to legend as the areas where most of our cities exist will be too dangerous to traverse. Current population is sparse enough in humanity’s future livable regions that there will be very little anthropological evidence to the common man of humanity’s past technological progress.