[morpheos137]

The world has always changed. We only have moderately good climatic records from dendrochronology for the past 1000 years or so. A meteor impact or supervolcanic eruption could disturb the climate far more rapidly than a few tens of decades burning fossil fuels. Life will go on. It always has.

[klyrs]

Life will go on, the earth will continue to orbit the sun. Even if the earth was flung away from the sun, life would go on, in the form of subterranean bacteria.

The thing we're concerned about is that humans are apex predators and depend on a functioning food chain to survive. Filter feeders eat algae. Unconstrained algal growth is toxic to fish (salmon) that we eat. Oyster and mussel farms were devastated and some won't see a rebound for at least 3 years if we don't have another event like this. Bears eat salmon, and when they can't find it, they seek other food sources like humans.

This story is a single datum. We've got freak cold snaps on the east coast and Texas. Flooding in Europe. The world is rapidly becoming more hostile to human life.

But yeah, a hot, acidic ocean will still support life -- maybe nothing we can eat for a few hundred generations, but life goes on with or without us. Hotter climes will spread tropical bugs and diseases; life goes on.

But we're still looking for intelligent life that's survived the "hold my beer" great filter. Haven't found such extraterrestrials; jury's still out on terrestrials.

[morpheos137]

often food chains are actually more of food webs. Most species, especially humans, are adaptable as their environment changes. Look at polar bears. They started out as normal brown bears. Then during the ice age they developed polar attributes, like white fur and maratime diet. If the climate in the arctic warms they will move inland again and likely merge with existing brown bear populations in the taiga. Those that don't adapt will die. That is how evolution works and always has worked.

In the past the environment has changed very rapidly at time. All life eventually dies. That which endures longer is that which adapts.

A warmer more carbon rich atmosphere has some benefits:

Expanded arable regions, fewer droughts, more rainfall, more carbon for plants to grown (try turning all your carbon in the atmosphere into rock and let me know how life fares then.)

Carbon based life needs CO2. They have done experiments where a forest is subjected to increased CO2 ppm by plumbing and nozzels. It grew faster and more robustly. Life also needs warmth. During the Eocene epoch some 50 milion years ago the Arctic was sub-tropical and teaming with life.