Global heating because of greenhouse gasses is an existential threat to society. It is the biggest threat we have ever faced (on par with nuclear war). And we are losing, big time.
EDIT: I wish downvoters would take the time to share their point of view.
Keep in mind that earth cannot get worse than the last time all CO2 was in the atmosphere. Trees are younger than sharks. There was plenty of life when all CO2 was free. Somewhere in that environment will be space for life like the last time. Sharks and trees and many other animals and plants made it though that environment. And somewhere in that environment, there will be some space for humans because we will be adaptable.
Instead, the biggest threat is AI. It's the new nuclear race. It will come as fast as human possible and it will have access to the most powerful weapons since any participant in that race will need that move to protect themselves.
Unlike CO2, AI will add something to the system that wasn't there before. Its power will be unmatched and unlike humans, it won't miss any lost life-form.
That's optimistic. Climate change is potentially reversible, but it would involve large-scale geoengineering or carbon capture that we don't have the technology for yet.
Developing and deploying that currently-nonexistent technology requires a stable, organized society. It's plausible that climate change could cause the breakdown of organized society before we're able to develop technology to reverse it.
Since bacteria is digesting cellulose this time, we can't rely on earth to fold over old wood. Instead, humans will have to manage the storage. But that should be doable, given the speed with which we can harvest forests.
But there's some tree that grows like a freaking weed and is amazing for carbon sequestration.
I feel like even having 'more' trees again would be helpful; where my family grew up, over the years all the big/old trees that were in people's yards were never replaced as they went away.
Also: carbon nano tubes and carbon fiber. We will build skyscrapers from carbon. There won't be enough carbon available for all the stuff we want to build.
Are you not aware of climate science or even basic astronomy? As the sun grows older and gets closer to the end of its live span it grows stronger and outputs more heat. The growth in solar irradiance happens over the course of millions of years with some lows and highs in the short term (we currently have an insane increase in global temperatures despite slightly lower solar activity compared to a hundred years ago but compared to 10-100 million years ago the sun is significantly stronger). CO2 that is emitted today has a much greater greenhouse effect than CO2 that had been emitted millions of years ago.
Global heating is worse.
Nuclear has a worse worst case scenario. But global warming is worse because it's not a hypothetical threat, it's something that is already happening.
Nuclear threat could be (and was) resolved with common sense, but the time to resolve global warming with common sense was 30 years ago. Now our best outcome is to mitigate its effects. In the best case scenario millions will die. Mass migrations and wars are likely to happen. Recent data even say that we might have underestimated the risk.
> Climate change is reversible in a couple hundred years [...] At worst many people will die but not the entire earth will be inhabitable.
The planet will be fine, our civilisation might not be.
Also, it’s not just about CO2 that’s just one piece of it. There’s also other gasses, like methane f.ex, to be concerned about. Besides gasses there are things like ice , water and cloud reflectivity.