this post was submitted on 22 Jul 2023
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[–] sibloure@beehaw.org 19 points 1 year ago (8 children)

Does this mean we're all going to die? Like humanity will be gone without a trace? If so, how soon?

[–] Imajustlayhere@kbin.social 23 points 1 year ago

It will probably be a drawn out process that's hurts real bad.

[–] DogMuffins@discuss.tchncs.de 15 points 1 year ago

No, but catastrophic collapse (over many years) is possible IMO.

As in a return to pre-industrial tech.

[–] bassomitron@lemmy.world 15 points 1 year ago

No. But many will. And we'll start seeing mass migration surges within the next decade from countries more drastically impacted.

[–] weavejester@lemmy.world 14 points 1 year ago (1 children)

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.

[–] Muehe@lemmy.ml 4 points 1 year ago (1 children)

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.

Source

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.

[–] weavejester@lemmy.world 1 points 1 year ago (1 children)

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.

[–] Muehe@lemmy.ml 1 points 1 year ago (1 children)

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.

[–] weavejester@lemmy.world 1 points 1 year ago

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.

[–] luffyuk@lemmy.world 9 points 1 year ago (1 children)

There's no way the climate crisis entirely wipes out humanity. However, we could be looking at a Mad Max style future.

[–] Zoot@lemmy.ca 5 points 1 year ago (1 children)

What do you mean by no way? People cant live underground forever, and itll get worse for more generations than is sustainable.

[–] luffyuk@lemmy.world 12 points 1 year ago (1 children)

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.

[–] Zoot@lemmy.ca 2 points 1 year ago (1 children)

I think the issue here is that you believe there will be any life living. Besides bacteria and what not, nothing will live if we continue down this path.

[–] Alperto@lemmy.ml 9 points 1 year ago

I don’t have a cristal ball to refute your answer but I have my knowledge about history and biology to disagree: life in earth has to main goals: survive and reproduce. There’re many species nowadays adapted to what most people consider extreme heat: from elephants to lions, hienas, giraffes, humans, many species of trees and bushes, etc. They will just survive by simply moving their migration routes somewhere else (plants and herbivores would start the shift, predators would follow them).

Humans are extremely adaptable, as you may see if you look at how there’s human life everywhere on the planet. We would need to adapt, for sure, but we as species will survive. That doesn’t mean it will be simple, but we will. Many years ago an expert said on a documentary (can’t remember, sorry) that the next world war would be centered about water control. I agree.

[–] Megaman_EXE@beehaw.org 6 points 1 year ago

My understanding is that over time people will begin to move away from hotter regions. The most at risk will be children, small animals, the elderly and the poor.

Impoverished nations will be hit the hardest and we'll see the most change happen to those places first. Scientists have said that as climate change gets worse and as temperatures get warmer, extreme weather events also become more common and worse as well.

As for how that will change for north America or Europe I have no real clue.

I live in a fairly northern location. We get down to -40°c sometimes in the winter. But even the winters are warming up and becoming more mild and the summers are getting hotter and less bearable. I would imagine we might face energy issues in the future if our countries don't adapt. There's going to be more demand as houses here will need AC going forward to stay cool. That or they need to start building new homes with better insulating materials that prevent heat transfer.

[–] sun_is_ra@sh.itjust.works 1 points 1 year ago

Probably people will have to go more north and general population of the world word drop and with it the pollution then planet recover and after couple of generations the survivors will return