Does this mean we’re all going to die? Like humanity will be gone without a trace? If so, how soon?
No; at least, that’s unlikely. But parts of the world that are currently habitable will be made inhabitable, and biodiversity will continue to fall. We’ll likely see more extreme weather events, increased migration from areas that are too hot or underwater, and issues with global food supply. Coral reefs may completely disappear.
However, progress is being made, and while it’s not as quick as we’d like, carbon emissions for modern economies like the US and EU are on a downward curve. In 2021 EU’s carbon emissions were back to pre-1967 levels, while the US’s carbon emissions were back to pre-1979 levels (Source). So there’s cause for hope; the worst thing we can do is give up. Everything we do now lessens the scale of the problem in future.
Does this mean we’re all going to die?
No; at least, that’s unlikely.
Well that “unlikely” there merits some debate I would say. Yes there is reason for cautious optimism, but there is also the very real possibility of climate change becoming an extinction level event for humanity, specifically by a cascade of tipping points through several globally relevant climate systems being triggered. The damages that will be caused just by optimistic projections of warming are not well understood either:
Even without considering worst-case climate responses, the current trajectory puts the world on track for a temperature rise between 2.1 °C and 3.9 °C by 2100 (11). If all 2030 nationally determined contributions are fully implemented, warming of 2.4 °C (1.9 °C to 3.0 °C) is expected by 2100. Meeting all long-term pledges and targets could reduce this to 2.1 °C (1.7 °C to 2.6 °C) (12). Even these optimistic assumptions lead to dangerous Earth system trajectories. Temperatures of more than 2 °C above preindustrial values have not been sustained on Earth’s surface since before the Pleistocene Epoch (or more than 2.6 million years ago) (13).
Even if anthropogenic GHG emissions start to decline soon, this does not rule out high future GHG concentrations or extreme climate change, particularly beyond 2100. There are feedbacks in the carbon cycle and potential tipping points that could generate high GHG concentrations (14) that are often missing from models. […]
There are even more uncertain feedbacks, which, in a very worst case, might amplify to an irreversible transition into a “Hothouse Earth” state (21) (although there may be negative feedbacks that help buffer the Earth system). In particular, poorly understood cloud feedbacks might trigger sudden and irreversible global warming (22). Such effects remain underexplored and largely speculative “unknown unknowns” that are still being discovered.
So is the extinction of humanity through climate change certain? No. But is it possible? Yes, and the likelihood is very poorly understood.
Another aspect that is often overlooked in this debate is that the beginning of the holocene mass extinction is very much pre-historic, insofar as the spread of homo sapiens over the globe closely matches to the extinction of mega-fauna wherever we appeared, unsettling ecosystems millions of years old, and reducing biodiversity further and further. Other ecosystems will only be able to compensate for so long before they go extinct, and so on, and the explosion of complexity that usually follows after a mass extinction happens on timescales longer than humanities existence. If or when this cascades to the top of the food chain is anybodies guess.
If a system is poorly understood, then by definition it cannot be factored into predictions. When we say something is “unlikely” we mean “it is unlikely based on what we understand”. I don’t think it’s very useful to ask, “Well, is it unlikely based on what we don’t understand?”, because that’s not a question that can be answered.
The possibility of a tipping point cascade is generally without dispute as far as I know. It is likely based on what we do understand, however predicting how likely exactly, the severity of consequences, and the interaction with positive and negative feedback loops from other climate systems is not well understood.
The consensus seems to be that it’s virtually certain with a warming of 4-5 °C compared to pre-industrial levels.
Ignoring an existential risk like that because one lacks understanding doesn’t seem wise.
Is a catastrophic, world-ending feedback loop likely based on what we understand? The IPCC reports paint a grim future, but I don’t believe any has suggested that it’s likely the entire Earth will be rendered completely uninhabitable to human life.
There’s no way the climate crisis entirely wipes out humanity. However, we could be looking at a Mad Max style future.
What do you mean by no way? People cant live underground forever, and itll get worse for more generations than is sustainable.
Civilization couldn’t exist as it does today, but humans are a resilient species. We will find a way to continue living, pretty much as long as life remains on this planet. Be that underground, at the poles, in bunkers, in a dystopian desert wasteland, humanity will persist.
This is the second time in a week someone has used “tumble” to mean “occur rapidly” instead of “fall”. Is this a new colloquialism or had"tumble" always had a second definition as “occur rapidly”?
If a condition is worsening (a “fall”) “tumble” applies just fine. Indeed, “tumble” is just a way to say “falling rapidly” in this context.
The reason “tumble” (and its notion of “fall”) is applicable is because the situation is worsening. If it was rapidly improving, nobody would say “tumble”; it’s not simply that it is occurring rapidly.
Taking a tumble referring to something that is worsening is another common definition that I’ve read countless times in reference to something problematically decreasing, I’ve never heard or read “tumble” used until very recently to describe a situation in which something is rising. Have you?
“falling rapidly” would make perfect sense in many other situations. “Food storage tumbles, democracy tumbles, winter temperatures tumble”, etc. But nothing is falling, all of the temperature records are rising.
Summer temperatures are so high they tumble?
This is a genuine grammatical question. I’m not trying to detract from your answer or the article itself.
I’m just very confused by this usage of the word “tumble” that I’ve seen at least twice now to refer to rising temperatures.
But nothing is falling, all of the temperature records are rising.
I see what you’re saying. I had taken the use to mean the situation is tumbling, not the temperatures. But upon a closer reading (of the title specifically) it seems a more reasonable interpretation of the word tumble is:
Climate records tumble,
The object of the verb ‘tumble’ is “climate records”. That is, the climate records are tumbling. A tumbling record is one which has fallen over and been surpassed. So what they’re saying by using the word “tumble” is: previous climate records have fallen over and been surpassed.
I do agree it’s a weird word choice, but I don’t think it’s wrong or even playing on a potential uncommon secondary definition. It’s not saying temperatures have tumbled, but rather records have tumbled.
