Why is it so commonplace now to conflate climate change with basically armageddon? I thought that most models predict some hard times (mass migrations and everything bad that comes with it), but species extinction (or even, civilization collapse) is still a fringe belief among the scientists.
[0] or indeed where everything is either "cold" or "hot", as someone recently posted here suggesting that global warming would solve the problem of EV batteries being too cold sometimes
[1] https://www.science.org/doi/10.1126/science.1159099
[2] https://www.theguardian.com/environment/2021/jun/29/risk-fro...
Also, there are many potential feedback loops that may put us on an irreversible course towards the planet becoming uninhabitable in the future [3]. There is still a lot of scientific debate about when we will hit these feedback loops and how significant they will be. Where you stand on this issue is often what separates the doomer climate scientists that think we're passed these tipping points from the optimist climate scientists that think it's still avoidable or the feedback loops will not be too significant.
Most climate modeling focuses on the years of 2050 and 2100. What happens if we continue to make little progress by 2050 or 2100? As long as CO2e emissions are above net zero, warming will continue, and the effects will continue to get worse. Even if we do level-off CO2e emissions and stabilize at 2°C or 3°C, that temperature and all the extreme events, places that are no longer inhabitable, and lower crop yields that come with it will become the new norm, making life a lot harsher for future generations.
[1]: https://www.ipcc.ch/report/ar6/wg2/
[2]: https://link.springer.com/article/10.1007/s10584-011-0149-y
This seems extremely overblown. The idea that the Earth will become "uninhabitable" seems ridiculous at best: the Earth has been "habitable" for literally billions of years, even when the climate was vastly different than it is now. And if you mean "habitable by humans" rather than "habitable by any lifeform", humans in particular have adapted to an extremely wide range of climates, from frozen tundra to middle eastern deserts.
Perhaps you mean "habitable by 7-10 billion humans with today's civilization and level of technology and standard of living"? It's hard to imagine the Earth ever becoming completely uninhabitable by humans; someone will figure out a way to survive, no matter the catastrophe. But it won't be comfortable like today, and the planet probably won't support today's population levels.
I used the wiggle word of potential because the severity of these feedback loops is debatable, but I don't think it's overblown at all.
If a tipping point does in fact exist and we pass it, it means we will be on an irreversible course to indefinite warming of the planet. To make matters worse, a positive feedback loop implies an exponential growth, unless some sort of negative feedback loop kicks in to counter it.
It is estimated that we have warmed the planet by 1.21C so far (as of 2021) since pre-industrial era[1]. In the worst case scenario (RCP8.5), temperatures will reach 2.5-4.9C by 2100[2]. It's worth pointing out the impact of temperature increase is exponential as well, i.e. 2C global temperature increase will make severe weather events 4 times more frequent than a 1.5C global temperature increase. Some studies estimate that all of earth will be uninhabitable by humans if the global temperature reaches 12C above pre-industrial era[3]. I don't think it's overblown to say this is possible within the next few hundreds of years, especially if these feedback loops turn out to kick in and start rapidly pumping more CO2 into the atmosphere than we do.
[1] http://berkeleyearth.org/global-temperature-report-for-2021/
[2]: https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/SROC...
[3]: https://www.sciencefocus.com/planet-earth/how-hot-could-eart...
Where is your intuition for this coming from? Note that 12C rise in global temperature is a very different statement than 12C rise in average temperature of where you live. The temperature increase is applied non-uniformly. Also, the volatility in weather scales exponentially with global temperature increase. For example, 1.5C to 2C rise is expected to create 4 times more extreme weather events globally.
>Life would probably greatly resemble a Max Max movie
We don't need a fictional movie to see what life would be like. We are seeing glimpses of it already with these mega weather events hitting areas with a higher risk index such as the recent flooding in Pakistan that resulted in 33 million people impacted, ~600K people displaced, ~2,000 people dead, and ~10 billion USD in damages:
https://en.wikipedia.org/wiki/2022_Pakistan_floods
update to comment: I just saw this article this morning -- a new study on those tipping points I mentioned earlier in our discussion:
https://www.theguardian.com/environment/2022/sep/08/world-on...
I really feel like you're looking at a worst-case scenario, comparing it to living in modern civilization, and concluding that modern civilization can't possibly survive such an extreme climactic change, and then concluding that humans will go extinct. I'm sorry, but that simply does not logically follow. Civilization can be destroyed, but this is quite different from all humans going extinct. The Mad Max movies may be fictional, but they do show how humans are able to survive in very extreme conditions, which has been proven countless times in history by humans who really did survive in extreme conditions (go talk to the Innuit for instance). Will 7.5B humans survive in such conditions? Obviously not. Will a few thousand? Quite possibly. It was only a very small number of humans that crossed the land bridge from Africa to the Middle East to populate the rest of the world.
The greatest risk from climate change is not from natural disasters directly like in Pakistan, but the downstream effects of frequent severe weather events and warming of local climates. The loss of life and levels of migration will be much greater when critical infrastructure such as energy production, food production, and clean water supply, are impacted.
Either way, humans going extinct or being reduced by several orders of magnitude is a dire outcome, and we should be doing all we can to prevent it.
A temperature increase exists where earth will become uninhabitable by humans. One study mentioned above estimates that temperature increase is 12C. It could be higher or lower, but we don't really know without further studies on the topic.
Before reaching that temperature, life on earth will become a lot harsher for all due to the effects of climate change, and we should be doing all we can to avoid those harsher conditions, regardless of what we think the upper bound temperature for humanity to continue existing is.
As it will lead to war, likely between nations who have large arsenals of nuclear weapons.
The Second World War will look cute compared to what will happen if we reach the 3-4 degree warming scenario's.
But declaring war against nations who are """migrating""" (invading them)? Sure.
CO₂ (a gas that life co-evolved with and depends on) simply isn't our most important environmental issue. let's focus instead on pollution: CO, NOₓ, SO₂, VOCs (PAHs & petroleum hydrocarbons, phthalates, alcohols, aldehydes, terpenes, ketones, formaldehyde, etc.), lead, mercury, ozone, radon & other radioactive elements, fertilizers/pesticides, plastics, and especially particulates, which are things that kill millions of people right now, every year (not to mention all the harm to everyone else as well).
the focus on climate change is fashion, but with a little tweak we can actually address impactful environmental problems instead.
[0]: nuclear, by the way, has the potential to help significantly, principally by removing coal, our biggest categorical polluter, from the energy mix. incidentally, that would also measurably reduce CO₂ emissions.
Strongly disagree. Climate change is a much bigger threat in the short and long term than pollution itself. See my sibling comment for more on that.
That said, it feels like a silly thing to argue about. We should be making efforts to reduce both general pollution and CO2 emissions. Fortunately, a lot of solutions in one area will benefit the other.
and it's clearly not threat to anyone living today and probably not for many generations to come, no matter what the 'trust the science' rhetoric claims. pollution, however, has been and will continue to kill millions of people every year. it has the potential to unite all sorts of factions (something vested interests fear) and actually make meaningful progress.
CO₂ and climate change is a sideshow, but it's been brought front and center because it serves a powerful purpose for those vested interests. anyone jumping on the climate change train is only furthering those interests, rather than solving real problems. instead, we should focus on the actual problems like pollution, and discard the chosen mediopolitical narrative.
I am not sure how to respond to this in productive way. You clearly deny the impact of climate change, and it is unlikely I will convince you otherwise, so I don't know if it's worth anyone's time. If you're open minded and want to have a conversation, maybe start by responding to the well understood impacts of climate change today, e.g. https://en.wikipedia.org/wiki/Climate_change#Impacts
the core problem with the climate change mediopolitical narrative is the focus on CO₂, which as i've noted before, is among the least important and most nebulous environmental issues, and therefore among the most attractive for political distraction and do-nothing gridlock. you see the effectiveness of this narrative all over hn, via the casuistry with which climate change is discussed.
in contrast with pollutants, which have squarely been introduced relatively recently by human industry, CO₂ is a gas on which life depends and has been abundant in our atmosphere for hundreds of millions of years. rising CO₂ levels is a long term issue, to deal with over centuries and millenia, not a short term one. pollution has been killing people for centuries now.
edit: to answer your question, there are many policy decisions that differentiate the two. what to tax, what to incentivize, what to regulate, what to evangelize, etc. we should be characterizing the externalities caused by each pollutant and then applying a tax or market-based solution (or whatever else) to address them.
[0]: to be precise, "more people", since our ecology inadvertently kills people all the time, throughout history.
"We found that 5,083,173 deaths were associated with non-optimal temperatures per year, accounting for 9·43% of all deaths and equating to 74 excess deaths per 100 000 residents."[1]
[1]: https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...
but it's easy enough to verify that there have been at least dozens of papers (and at least hundreds of news stories) on coal by itself having killed millions of people over the past century and a half, and having nothing to do with CO₂ or climate change.
Also, they can short circuit a discussion. In fact, here are two articles that cover the exact topic we are discussing, and largely summarize the issue as climate change is a bigger threat and they are two sides of the same coin anyway:
https://www.nationalgeographic.com/science/article/why-clima...
https://www.unep.org/news-and-stories/story/air-pollution-an...
Can you point me to some sources that helped you reach your conclusion, or is this just an idea you came up with by looking at deaths due to pollution compared to deaths due to climate change historically?
as for the second, i agree that pollution and climate change are linked, but why address the boogeyman when we have the villian right in front of us? [insert tribal, mediopolitical reasons unrelated to making lives better.] pollution is clearly a problem now. climate change might be a problem in decades/centuries. and the causation is pollution -> climate change, not the other way around, so fixing pollution (not simply CO₂) is win-win, but not the other way around.
a long arc of digesting and triangulating information has led to my understanding of the problem, which doesn't easily link to a study or two. i'm a proponent of sensible environmentalism, not tribal bandwagoning. i was a member of https://netimpact.org/ in business school and took courses on sustainability (i.e., i've studied the problem using primary sources rather than relying on mass media to tell me what to think).
> pollution -> climate change, so fixing pollution (not simply CO₂) is a win-win
Imagine a world where everything between the Tropic of Cancer and the Tropic of Capricorn is essentially uninhabitable due to consistently high Wet Bulb Temperatures. Right now, we have over 3 Billion people living in that band (40% of humanity), and about 30% of all commercial agriculture is done here. Bye-bye to both.
Imagine a world where everything between the tropic of that hemisphere and the Arctic/Antarctic circle of that hemisphere has massively chaotic weather, such that commercial agriculture at any significant/effective scale is either impossible or produces utterly unreliable crops from one year to the next. This is where the other 5 Billion (60%) live, and where the other 70% of commercial agriculture is done. Humans could probably live here (although Wet Bulb temps would also make large chunks uninhabitable for parts of the year), but where will the consistent and reliable supply of food come from? Not this part of the world, that’s for sure.
This leaves only the Arctic and Antarctic, which will be quite warm at this point, but has almost no topsoil (or even arable soil in the first place) worth mentioning, and could produce enough crops for only about 2-3% of current human populations.
Now imagine the other 97% of humanity fighting tooth and nail for the right to subsist off of the consistent and reliable food supply from this agriculture-poor part of the planet. Most people who are starving and desperate will gladly shred and decimate infrastructure if it means that they can live another day. And this is the infrastructure that permits efficient, large-scale agriculture and distribution systems that can feed civilizational populations above the single-digit millions level.
Sure, humanity will likely linger on for another century or two. But not as any sort of a serious technological society, nor in any significant numbers beyond the low millions.
Modeling the future of a species of billions, many irrational actors, is too complicated to put my trust in scientists today.
My MSc in math may be old now; maybe I’m getting the math wrong, but I don’t need a math degree to know every scientist is a fallible human and fallible humans often lie unintentionally or intentionally to keep the peace and maintain their paycheck. Who wants to be the scientist that is all “end of the world is coming.”
Many “scientists” in industrial roles were complicit in keeping climate change evidence hidden since the 1860s.
“Authority figures” is the dumbest social construct we cling to.
We have no baseline for human behavior after another 100 years of climate change. Future hasn’t happened yet, past experience is not viable as it lacked the new constraints of the future.
There is evidence in biology that we go crazy after years of living in hot weather. The body heats is better than it cools us, and cooling us strains our systems.
So perhaps it can be shown in some academic way our biology could literally survive the conditions, but they can’t predict how well humanity will actually deal with it; we may destroy ourselves over resource constraints or the wrong people going mad, launching the nukes out of paranoia.
There are too many ways we can end ourselves to take the prediction “it won’t get too hot for the species to biologically survive” as evidence we won’t still destroy ourselves.
Constraining the prediction only to that which they can have most confidence in undermines the accuracy of the model.
This reads like nonsense to me.
Why are you talking about human bodies in warmer temperatures? What do you think goes into a climate model?
Parameters could be over or under weighted given current state, choices of scientists.
And we have ZERO data points from a future where people actually are living with another 100 years of climate change; we could be massively over or under weighting without historical data of a future that hasn’t happened; your goal is rife with paradox and uncertainty; how do we use our trend modeling tools that rely on historical data without historical data from a future we haven’t experienced?
All our model is is old data points and some guesses at trends which may or may not hold. Scientists now cannot force people to stick to their model.
These are mathematical truths too, sorry you don’t have the context. I’m just gonna be done here. Cya later bye.
https://www.theguardian.com/environment/2022/jan/27/word-sal...
Anyway, I think the main disconnect is your misunderstanding about how climate modeling works. It's much more about the physics of GHGs in the atmosphere and how those impact the global temperature and the downstream effects on local climates and weather patterns. Human activity can be summarized as: humans emitted 51 billion tons of GHGs last year and that number continues to grow.
Constraining “survivability” to one metric is stupid.
Was tired and busy yesterday. Got rambly.