Climate endgame: exploring catastrophic climate change scenarios | Hacker News Reader

Climate endgame: exploring catastrophic climate change scenarios

pnas.org

73 pointsanigbrowl57 comments

Amazing. I wish there were more discussions about this most important topic on HN, and more generally on describing how we are depleting earth’s resources and dispersing them everywhere, transforming it into a giant pile of garbage (gaseous garbage in the case of GHG). Sadly, climate change is not even the only imminent threat, when 60% of vertebrae have disappeared in 50 years for example, among many others…

We need to invent a new storytelling for society to have an organized energetic and material de-growth, so that we don’t have to undergo a disorganized one, forced upon us by nature, that would be orders of magnitude worse.

Technology can be a huge help in organizing this de-growth, so I guess HN could be a great forum for collectively imagining how to do it!

De-growth means lowering humanity's total energy output. Lowering our total energy output means lowering humanity's average life expectancy, quality of life, and the size of our overall economic pie. These are all negative side-effects with comparable potential for societal destabilization as the effects of rising sea levels or increasing global temperatures.

There are solutions to climate change that avoid de-growth and its many negative consequences, such as increasing our investment in nuclear energy. Some states already see things this way, such as China, where the government has announced plans to build 150 new reactors by 2050:

https://www.bloomberg.com/news/features/2021-11-02/china-cli...

De-growth shouldn't significantly lower average life expectancy - after all in developed nations a high percentage of deaths are due to lifestyle decisions that are only possible because of our high use of technology and exogenous energy sources. As long as we still retain the knowledge on how to treat most diseases, and the physical infrastructure of our health-care systems, there's good reason to suppose average human health/life expectancy might well improve with the right sort and amount of de-growth. "Quality of life" is much harder to judge. It would definitely feel like a step down for many people used to just having everything and anything they want delivered to their door at the click of a mouse button. And it's true there's no good example that I know of a large population smoothly transitioning into a lifestyle with a significantly lower material standard of living. But I'm not convinced it couldn't be achieved in such a way that most people would come to accept that we've gained more than we've lost.

Our ability to transform matter at always bigger scales and rates, which is proportional to the energy we master, is what has driven the current environmental crisis (were not all the imminent existential threats are climate change, although climate change is the most obvious one).

If we keep the same consumerist and expansionist culture and add more energy to the mix (even if it’s climate-friendly energy), i.e. more capacity to extract resources deeper and deeper, become more dependent on them and disperse them in our constructions, devices, ground, water and atmosphere, what do you think will happen?

Energy will be key in amortizing the pains of de-growth, but de-growth will happen on a planet with finite resources, whether we want it or not.

We have no issue with finite resources. We have plenty of energy and raw materials for everything we want for a long time.

The challenge is working out how to access those resources in ways that don’t harm our lives. That is a technically possible challenge, but the problem is that it is much more efficient in the short term to harvest resources in a destructive manner. Without some sort of collective action, the destructive manner simply outcompetes the sustainable methods.

Agreed about the fact that collective action will be the solution. But about resources it is true that we can harvest them in a less destructive manner, will that be enough? Or do we also need to harvest less of them?

The gap we need to bridge is to harvest in such a less destructive manner that 1) they can regenerate themselves at the same rate as we harvest them, making our civilisation actually sustainable 2) they don't harm us directly indeed.

Can we bridge that gap by harvesting in a less destructive manner?

1) How is the phosphorus - vital for our current food system - that we harvest in mines concentrated for us during billions of years going to regenerate? Same for oil, gas, rare metals, all the silicon and metal that we disperse in our devices etc etc going to regenerate themselves? Should we bet on our ability to figure that out in the next 30-50 years? 2) so far the rate at which we harm ourselves due to the amount of garbage we throw at nature (i.e. everything we make, build and reject) has only increased with progress. Should we bet we are going to reverse that just with technology in the next 30-50 years?

If we lose the bet, the consequences are never seen in history.... I'd rather bet on more reliable methods to survive...

The resource consumption is a huge for climate change catastrophe. Resource is also not plenty like you said, it's bs by capitalist.

Which resource is really limited? Raw materials are rarely destroyed, only converted to other things... if you have enough energy, you can reuse them... so energy is the limiting factor, and there is PLENTY of energy to harvest.

1) Energy is the limiting factor IF we decide to do different things than we have done so far. So far what we have done with energy is mainly deplete and destroy things. In other words: we are very clumsy in the way we control matter, we cause tremendous side effects with our actions that are going to end up swallowing us back into the abyss if we don't change.

2) Energy being the limiting factor is in itself a huge problem, given the amount of energy your problem requires: the amount of energy required to get the original quality raw materials back from an iPhone is orders of magnitude bigger than the one that was needed to extract them from nature in the first place. It seems irrational to bet on this as a means for getting to a sustainable model in the short term (30-50 years).

All natural resources are limited based on which are are alive. You might be living in a bubble in a privileged place.

This is an unscientific viewpoint. The current climate crisis has been driven by man-made carbon emissions. Our ability to transform matter at always-bigger scales, or merely at the scale of our current rate of consumption (see declining global fertility), does not rely solely on carbon-emitting forms of energy production.

> Lowering our total energy output means lowering humanity's average life expectancy

This is totally illogical -> oversized cars and consumption of meat are the biggest consumers of energy, and they only cause death. They serve no practical purpose society wide.

Rather, what we need is lowering humanity's total energy input. That same approach has been preached by MBA business types for decades, under the moniker "efficiency". I don't see why we can't do for energy efficiency what we've been doing for labour efficiency for decades, but it does require a more comprehensive management focus.

I don't see a-priori how "de-growth" should lead to lowering living standards, other than by implication of the (IMHO ill-chosen) word.

I'm pretty sure the average person in my country consume at least half the average american does, and we still have a better life expectancy. And i'm not sure, even not accounting for the hapiness treadmill, that the QOL is higher for the average american. Depends on your hobbies i guess?

Degrowth doen't mean reducing life expectancy. It's not.

All the growth people talk about is increasing quarterly profit in board meetings. That's what is causing the catastrophe.

Your reasoning is flawed, technically if we make things last longer, be repairable, skip vacations on the other side of the planet and stop buying so much cheap plastic crap we would most definitely "degrow" but the quality of life would at least remain unchanged.

Capitalism is a beast that needs constant feeding, it doesn't do much good in many cases, it's just growth for the sake of it.

The vast bulk of global energy production does not go towards "cheap plastic crap" or vacationing. It goes towards transportation (which affects the base cost of practically all economic activity), industrial uses that are essential to healthcare, construction, and agriculture, and the heating and cooling of our living spaces and places of work. These expenditures will only increase as the world's human population increases to a projected ceiling of around 10 billion. In addition, replacements for "cheap plastic crap" may consume more energy to produce, even if their production emits less carbon.

There are certainly efficiency gains to be had. They will not be made overnight. America's housing stock alone can't be replaced in a week, or a year, or a decade with hyper-insulating, low-emission construction materials. Changing from one mode of construction, consumption, or production to another has an energy cost, too.

https://www.newscientist.com/article/mg25133463-500-how-to-u...

https://www.e-education.psu.edu/earth104/node/1346

https://ourworldindata.org/future-population-growth

Kate Soper makes the case that quality of life would improve significantly if we took these steps. The carbon-intensive "good life" leaves us time poor and stressed.

You can argue how much a change in quality of life it is, but not being able to travel or buy cheap plastic things is certainly a reduction in quality of life.

About transport - we can always switch to greener alternatives. Forbid oil-based flying, and the need to travel will bring new solutions.

Plastic is a crap and poison from the time of manufacture, not enhancement of quality of life. There is nothing (except medical equipment maybe) positive about it.

Preach

Does degrowth mean have to mean lower quality of life, or could it mean continued improvements in quality of life for a smaller population?

You aren't going to get anyone to embrace de-growth by telling stories. Instead, find ways that technology can enable continued growth while simultaneously decreasing environmental impact. If you force people to pick between global warming versus a major step down in living standards, a lot of them are just going to say screw it and pick global warming.

Everyone tells themselves stories. Like « what’s cool in life is to try and be a billionaire so I can get a private jet and everybody treat me like a king », or, at the level of a country « we should build entire new cities and airports and stimulate growth to increase GDP which is the main metric measuring our success » or, if you are an economist: “what nature has concentrated for us for free for millions of years, like oil, clean air, water, sand for construction etc, is free”.

I’m not talking about telling stories to people but about changing theses stories they already tell themselves that have been implanted into them by a system

> Technology can be a huge help in organizing this de-growth[..]

Errm, what?

Apologies for appearing to be negative, but isn't technology one of the main contributors to the mess we're in?

Absolutely agree, I didn’t want people to fixate on this fact so I preferred focusing on the positive and not mention it, but technology alone without deciding collectively how to repurpose it (this is a huge philosophical/cultural change where we need to decide together that black Friday and going to space for fun are lame, for example) is not going to be the solution.

As you said so far we have observed it has only made the problem worse, year after year after year! And with the little margin we have left, it’s irrational to take the bet it’ll change by itself and just “improving”.

I think one of the challenges that the movement faces is that since the 1960's, there have been many disaster claims - sometimes bordering on the fantastical - and they simply don't come to pass.

Not sure why this go-around should be given more credibility.

Let me give you an example. Back in the 1990s the ozone hole was considered a serious problem. Scientists argued that with unchecked emission of CFCs the hole will grow larger and cause serious harm.

Limits on CFCs were implemented, the hole stopped growing.

Pfft, scientists, warning against a disaster, which never comes because we worked to prevent it. What do they know?

Because climate models have largely delivered accurate predictions since the 1970s.

> In general, past climate model projections evaluated in this analysis were skillful in predicting subsequent GMST warming in the years after publication. While some models showed too much warming and a few showed too little, most models examined showed warming consistent with observations, particularly when mismatches between projected and observationally informed estimates of forcing were taken into account. We find no evidence that the climate models evaluated in this paper have systematically overestimated or underestimated warming over their projection period. The projection skill of the 1970s models is particularly impressive given the limited observational evidence of warming at the time, as the world was thought to have been cooling for the past few decades (e.g., Broecker, 1975; Broecker, 2017).

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL08...

For the past 20 to 30 years, the climate science community has been consistently nothing but EXTREMELY conservative in all their predictions in order to not being labeled as alarmist. Newsflash: they were STILL labeled alarmist AND also ignored because whatever happens in 50 years is Someone Else's Problem, can't be bothered to think beyond the next quartal or election cycle. Look! A shiny new thing! Consume! Consume! Now it's becoming clear that almost everything is happening way faster than the conservative models estimated. Humanity just. can't. win. against itself.

> conservative in all their predictions in order to not being labeled as alarmist. Newsflash: they were STILL labeled alarmist

It doesn't matter how reasonable you try to sound, some people will still hate what you stand for. They don't require logic to hate you, and they don't require the claims against you to be true. And if you compromise your principles to appeal to these people, you will loose support from both sides.

So you might as well stick to your guns and put these people on blast.

https://www.amazon.fr/Black-Swan-Impact-Highly-Improbable/dp...

Using the past to try and predict the future, in particular unusual and impactful events is a reliable way to constantly miss the main events of history.

Also there is no equivalent to the current disaster claim… and contrary to previous ones you can already observe the beginning of the effects of the current one… even though we are just at the beginning of its exponential-driven effects.

Long story short: that’s fine if you are still skeptical we’ll start working on it and in 5-10 years the people who are still skeptical will join us once they are more convinced by what’s happening in the world, down to their neighborhood.

Maybe we because we can observe these disasters happening in real time?

I find it absolutely wild that you can claim not to see climate disasters that are actively unfolding around us.

The first thing that really woke me up was the sudden loss of global sea ice in 2016. Take a look at the arctic death spiral if you aren't familiar already [0]. In 2012 if you mentioned that the response was "well yea but the antarctic is growing!!". There were good explanations for why that what happening during global warming, but that's no longer necessary since the antarctic is also declining rapidly [1].

Then there's lake Mead. I can't imagine you haven't been paying attention to what's happening there but we're on the path to reaching dead pool in a few years [2]. And yes, this is also due to poor resource management, but it is exacerbated by climate change and desertification of the region.

Then there's the amazon rain forest, which was once a carbon sink, becoming a net carbon emitter [3]

But the most important part of all of this, is that these events (which represent just a few examples of the impacts of climate changes) are not the new normal. Because the rate co2[4] and ch4[5] are being emitted is accelerating we're no where near a new stability point. All of the things we see now are just the beginning of a process that will only continue to accelerate each year for the rest of your life.

And that's just what we can observe and predict. Thwaites glacier, for example, will very likely collapse at some point in the next 100 years. We have no idea when, but when it does it will cause massive and near instant sea level rise. Far more concerning is that this tons of geological evidence that there are feed back triggers that cause rapid rise in GHGs and temperature and we don't know exactly when we might cross these. The book Under a Green Sky, by paleontologist Peter Ward lays out rather convincing evidence that the majority of extinction events have been caused by rapid climate change triggered by changes in CO2.

I'm not sure why you don't give these things more credibility.

0. https://www.arcticdeathspiral.org/

1. https://twitter.com/ZLabe/status/1540742236807213058/photo/1

2. https://mead.uslakes.info/level.asp

3. https://www.theguardian.com/environment/2021/jul/14/amazon-r...

4. https://gml.noaa.gov/ccgg/trends/

5. https://gml.noaa.gov/ccgg/trends_ch4/

you know how in the boy who cried wolf, there is a wolf.

If that's your takeaway I don't think you're getting from the story what you're supposed to.

I mean if we're going for snarky takedowns how about "if you identify most strongly with the attention-seeking liar in the story I don't think I need your advice."

But more seriously you can take more than one lesson from a tale. "A threat may be real even if the one relaying it lacks credibility" is not a neat or satisfying morality lesson to feed to children, but it remains true in my experience.

No matter how bad it gets, Earth will always be more habitable than anywhere else. But even if humans survive for millions of years, we’ll never get back what we have now.

If humans survive for millions of years we'll almost certainly transform the planet vastly further than anything even conceived of so far (except perhaps in SciFi). And I wouldn't assume that even within a few 1000 years Earth will be more habitable than elsewhere (but yes, it's almost guaranteed for the next century or so at least). OTOH, if we really did somehow totally self-destruct as a species, there's good reason to suppose the climate would settle back to something similar to what it has been the last 10k years, though it certainly won't last forever, or even much more than a dozen or so more thousand years.

No, it's too late, we won't ever get back to last century climate, Oxydes are some of the most stable molecules on earth, so the only way to get them out of the mid to high troposphere (where it actually have an impact) is to lower their concentration in the low troposphere.

At the moment, the CO2 you emit will take roughly 20 year before it has an impact on climate (the time to reach the altitude necessary for the re-emission to cause real harm). When we start planting trees and let the ocean capture the Co2 (they will acidify, but fuck the plankton and corals at that point, we can't do anything about that), then it will start to get better. It will take roughly five hundreds years to eliminate half of our past an current emission (if we stop in 2050) and ten thousand to get back to 1850 climate.

So, yeah, it will settle back, but in a long, long time.

Fucking the plankton isn't a good idea when the phytoplankton absorb 40% of all CO2 emissions.

Source: https://en.wikipedia.org/wiki/Blue_carbon

It won't fuck the phytoplankton that much, it is the zooplankton that will suffer (and yes, this will have effect on the phytoplankton, but like I said in another comment, consequences are too hard to evaluate.

10 thousand years is a little longer than I was thinking, but OK - it's a lot less than the millions mentioned by the GP.

Think of it as the half life of CO2 being 500 years (that's not that, but the curve is similar). The climate in 5000 years will be sufficiently similar to the one in 1850 for everything to settle back.

Except to be honest, we're not sure. The ocean will also probably reemit in the atmosphere some CO2 it is capturing right now (becoming less acidic), so with absorption slowing down, we're not sure how it will go. We know that it will need at least 10 000 years to get back, but we might ignore other phenomenons. Maybe bigger (so higher) Cyclones will accelerate the time needed for the excess CO2 in the high tropsphere to come down.

The sad, harsh and i guess also beautiful thing about this climate change event is that it is a full-scale experiment that have never been done before, that will change everything and on which we don't have enough theories to predict exactly what will happen.

CO2 levels, maybe. But it won’t bring back the extinct species or drowned cities.

No, but there's every reason to expect there'd be an explosion of new species. I'd much rather that happen while there are humans around to witness it of course but I'm not sure if we deserve to.

> there's good reason to suppose the climate would settle back to something similar to what it has been the last 10k years

What's that good reason?

My understanding is that the natural CO2 cycle would gradually remove the excess concentration currently in the atmosphere. I don't know how long it might take, several centuries at least I suppose.

Other than the easily available fossil fuels, this planet will be essentially back to the wild state a few tens of millennia after a hypothetical catastrophic collapse in technology.

> Last-resort emergency measures like solar radiation management (SRM), the injection of aerosols into the stratosphere to reflect sunlight (35). Whether to resort to such measures depends on the risk profiles of both climate change and SRM scenarios. One recent analysis of the potential catastrophic risk of stratospheric aerosol injection (SAI) found that the direct and systemic impacts are under-studied (36). The largest danger appears to come from “termination shock”: abrupt and rapid warming if the SAI system is disrupted. Hence, SAI shifts the risk distribution: The median outcome may be better than the climate change it is offsetting, but the tail risk could be worse than warming (36).

> There are other interventions that a better understanding of catastrophic climate change could facilitate. For example, at the international level, there is the potential for a “tail risk treaty”: an agreement or protocol that activates stronger commitments and mechanisms when early-warning indicators of potential abrupt change are triggered.

I like the idea of a "tail risk treaty" as a way for skeptical nations to hedge their bets and prepare for unilateral geoengineering.

> An existential risk is usually defined as a risk that cause an enduring and significant loss of long-term human potential (51, 52). This existing definition is deeply ambiguous and requires societal discussion and specification of long-term human values (52). While a democratic exploration of values is welcome, it is not required to understand pathways to human catastrophe or extinction (52). For now, the existing definition is not a solid foundation for a scientific inquiry.

Dark comedy.

I'm surprised that this paper doesn't mention hydrogen sulfide, a poisonous gas emitted into the atmosphere during anoxic ocean events, which is thought to be responsible for several known periods of mass extinction:

https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extin...

https://en.wikipedia.org/wiki/Anoxic_event#Atmospheric_effec...

>The trigger for these mass extinctions appears to be a warming of the ocean caused by a rise of carbon dioxide levels to about 1000 parts per million

To me, this is the most concerning potential result of climate change. Short of hermetically-sealed self-sustaining biodomes, which must run smoothly for up a million years before the atmosphere naturally clears of H2S, an event like this could wipe out all human life on Earth. Our political or ideological alignment would be of no consequence. Even communist utopian societies can't survive a poisoned atmosphere.

We'll hit 1000ppm in a few centuries if current trends hold, or much sooner than that if certain positive feedback loops kick in. Last I checked, the methane clathrate gun hypothesis wasn't as bad as previously thought, but we simply don't know what we don't know in this area:

https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis#Curre...

In all Earth's history, has there ever been Climate Stasis?

How can one not be skeptical when every existing model fails to even come close to predicting future temperature patterns, and every publicized prediction about climate catastrophe over the past 50 years has been wrong?

Where is the science?

Your ignorance doesn’t mean the science didn’t happen. The predictive models from decades ago have held up quite well, while deniers have moved from one wrong excuse to another.

https://climate.nasa.gov/news/2943/study-confirms-climate-mo...

https://arstechnica.com/science/2012/12/ipccs-climate-projec...

A quick google search gives us plenty of past published projections and how they fared:

https://www.carbonbrief.org/analysis-how-well-have-climate-m...

You can also watch Carl Sagan break it down in front of congress back in 1985 for just 15 minutes of your time

https://www.youtube.com/watch?v=Wp-WiNXH6hI

Do you mean because the impacts of climate change continue to happening faster and more severe than expected?

Don't feed the troll

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