No, we don't. Even in the worse case scenarios, a runaway greenhouse effect a la Venus was never remotely part of the scientific consensus. Heck, the IPCC just retired the worst case RCP 8.5 scenario saying it is now scientifically implausible. Now a big reason it was deemed implausible is the transition to renewable energy is happening. But even if RCP 8.5 did happen, it was not a humanity ending scenario.
Arguing over whether we all die or we all don't cheapens the risk of the death of millions if/when wet-bulb temperature limits (> 35C,95F at 100% humidity) become routine in populated geographies.
I would not take solace in IPCC retiring a scenario. Their predictions are based on conservative aggregates of existing science, and have always been considered by many in the climate science community to be underestimating climate change.
> have always been considered by many in the climate science community to be underestimating climate change.
This is exactly wrong as it relates to RCP 8.5. A number of research papers came out basically showing how 8.5 was completely implausible, and it was only after these papers were widely cited and reached consensus did the IPCC retire 8.5.
This article by some of the original authors of one of those papers explains the situation well: https://www.theclimatebrink.com/p/on-the-death-of-rcp85 . If you actually read their linked research paper, I don't think any unbiased observer could think 8.5 is plausible anymore (and, in fairness, 8.5 was always proposed as a worst case scenario, not a "business as usual scenario", as that climatebrink article explains very well).
This idea that climate change would lead to "ending humanity" just shows to me how a lot of the popular messaging outran the actual science on the issue.
Again, a "runaway Venus" was never really in the cards. As far as I am aware, basically all the carbon that is now locked in the ground in fossil fuels was once in the environment, and Earth still supported copious life at that time. E.g. at one point when dinosaurs roamed the Earth, there were no polar ice caps (Antarctica, even when it was near its current position over the South Pole, had lush green forests and lots of dinosaurs, even with many months of darkness), sea level was many meters higher, but life still flourished.
I'm not downplaying climate change. A significant, geologically fast rise in global temperatures would kill millions/billions of people, inundate coastal areas, result in major migrations and resource wars, etc. But "ending humanity" by making the entire planet unlivable was never supported by the science.
For another 50 years after we do stabilize them, yes.
The contrarian throwaway said: "A significant, geologically fast rise in global temperatures would kill millions/billions of people, inundate coastal areas, result in major migrations and resource wars, etc."
-- this sounds close enough to what I said, simply "We all die." I didn't say the oceans would evaporate. But with that amount of damage, global civilization and culture would probably not survive. Going carbon-neutral is not a "meh, let's do it later, or not" type of thing.
> this sounds close enough to what I said, simply "We all die."
This is not just arguing over semantics. There is a huge difference between what I wrote and "we all die". The global population is 8.3 billion. Climate change would be most catastrophic to poor populations in heat prone areas like Southeast Asia, parts of Africa, parts of Mexico, etc. where the wet bulb temp would exceed human survivability. Also, coastal cities would have to build defenses or move.
But we could lose one or two billion people and there is nothing that makes me believe that "global civilization and culture would probably not survive". I just done see how you make that leap. There would be huge change but plenty of places would be perfect for human habitation, some moreso than today.
But there is not unlimited carbon to burn. All that carbon in the ground was in the air/water at one point in Earth's past, when Earth was teeming with life.
There is scope for cautious optimism. Certainly the changes in train around the world (and being wound back in the US) are well and truly heading in the right direction, and at pace. It's a matter of perspective.
We're now, in 2026, currently at 1.5 degrees above baseline. This used to be the threshold at which we decided it would be too late and everything would be fucked and human civilization would inevitably collapse.
That won't happen, of course, since we kept increasing the threshold every time we approached the previous threshold. Luckily for us now, human society won't collapse until we hit 2 degrees!
> This used to be the threshold at which we decided it would be too late and everything would be fucked and human civilization would inevitably collapse.
Man, reading these comments is making me realize how crazy the messaging on climate alarmism actually got. No, 1.5 C was literally never the threshold where "everything would be fucked and human civilization would inevitably collapse." Where are people getting this misinformation? It wasn't from the IPCC, nor from the broader scientific consensus, nor was it part of the Kyoto or Paris Protocol statements. Yes, there would be colossally bad impacts, but "everything would be fucked and human civilization would inevitably collapse" is just total bullshit.
its science journalism tbh, the realities of climate change's impact is so spread out and complicated that it's difficult to communicate to a largely scientifically-illiterate audience. see the perennial confusion over cold heavy snow winters being an artifact of global warming due to increased energy in the weather systems causing more volatility instead of just a simple "everything is warmer now."
so journalists focus on Number, because Number is simple and understandable. even when Number is mostly or completely bogus.
Who is this "we" you reference? There have always been fear sellers (as well as their cult followers) and their predictions have always been pure fantasy but most of society rightly ignores them.
No, we don't. Even in the worse case scenarios, a runaway greenhouse effect a la Venus was never remotely part of the scientific consensus. Heck, the IPCC just retired the worst case RCP 8.5 scenario saying it is now scientifically implausible. Now a big reason it was deemed implausible is the transition to renewable energy is happening. But even if RCP 8.5 did happen, it was not a humanity ending scenario.