> The world was wrong to expect that climate change would trigger rapid and widespread desertification in the world’s arid lands.
That's the problem with a simplistic climate story. Climate change is chaotic. The deserts may go green while the oceans die. Increased storms threaten your house. That's not to say that some things about climate change aren't beneficial, it's that, on balance, most of climate change is bad, at least from a peaceful human civilization perspective.
> That's not to say that some things about climate change aren't beneficial, it's that, on balance, most of climate change is bad, at least from a peaceful human civilization perspective.
I think it’s hard to know what ‘bad’ means here. I think that the truth is climate change presents a great uncertainty and it could be quite bad or it could not be so bad as we think. We have no real idea, we just have projections and estimates of physical phenomena that are based on our understanding of science and the world. These projections will likely come true to a degree and they’ll also likely be wrong to a degree, and we have no idea how that will change humanity in the process.
That’s really scary and it’s the first time that humanity has ever faced such a large and unavoidable uncertainty. All that said, I don’t think we have the computational models to predict what happens when you increase the temperature on earth for a century. We have no idea if other reactions will trigger and cause unforeseen effects. Each rung of uncertainty presents potential for mass death, but not certainty of it. Only uncertainty.
Strong disagree. I really dislike this "well, we just don't know what's going to happen!" take just because there is some uncertainty around the edges.
Just take one dead simple example that we know with a quite high degree of certainty - sea level rise. Coastal communities just happen to be where most of humanity lives (here is a nice map from the Map Porn subreddit, showing areas of equal population in the US, where the areas along the coast basically contain the same population as everything else: https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fs...).
It's not hard to game out how much devastation there will be with 2, 4, 8 meters of sea level rise, and if anything we've been finding recently that our calculations of ice melt have been too conservative.
A lot of the more immediate impact of sea level rise, though, is increased frequency of hard to predict storm surge. And while we know there's sea level rise, we don't know how much; if we knew sea level rise would stop at +4.2 feet we could build infrastructure to deal with it (at least in the developed world) ... it's much harder to build infrastructure to deal with these challenges when rise might be +2 feet or +10 feet.
I'm not a climate scientist so take this in the curious vein that it is intended, but do we know that the uncertainty is only around the "edges"? From what I know about weather forecasting, relatively small changes in initial conditions can lead to rather dramatic differences in outcomes. It's my understanding this is how they get to the probabilistic estimates like "40% chance of rain"...they run a bunch of different models with slightly different initial conditions and 40% show rain.
Genuine question: if there is relatively large uncertainty at the small geographic and temporal scales, why wouldn't that also propagate to even larger amounts of uncertainty at larger scale models? (FWIW, I'm not trying to wordsmith around the word "bad" but rather pin down the uncertainty aspect of the claim.)
The larger scale models aren't necessarily built on the smaller models, they are independent and generally less specific. They are probably even inputs to the more specific models. So, like rising sea levels and increased temps (on average) is basically guaranteed, the _exact_ change for a particular place is more uncertain.
Neil deGrasse Tyson in his Cosmos show described it like a person walking a dog. We don't know where the dog will be exactly, but we can see the person with the leash is moving in one direction, and the dog isn't going to ever get too far from him (because of the leash).
But the uncertainty in the dog analogy is the length of the leash. If we don't know the length of the leash, we can know the general directionality but can't make very strong conclusions about where the dog will be, right? I don't know that this supports the idea that uncertainty will only be around the edges; I've heard NDT talk about the opposite: even a small shift in in the average causes relatively large changes in the probability of (previous) long-tail events.
A more accurate drill down on the analogy would be that we don't know the exact length of the dog' leash either, but we do know what the limits of it are. We know it's not a 1 km leash, but the "uncertainty around the edges" encompasses not knowing if it's 2 m or 0.5 m.
Part of the accuracy of the analogy is that just like when you see the human from a long distance, you don't know exactly how long the leash is, but you do have a solid expectation of the rough upper bound for the dog's distance from the human even still.
With climate change you're talking about having seen the human walk half way down a block already. You can see they're continuing to walk the same direction, and everyone agrees they'll continue walking to the end of the block if nothing changes. Do we know exactly where the dog is during that whole walk? No, but we do know it will cross a line two thirds of the way down the block sometime before the human reaches the end of the block. And the likelihood of the dog crossing is greater and greater the further along the block the human is.
>but we do know it will cross a line two thirds of the way down the block sometime before the human reaches the end of the block.
I'm trying to be careful here because I don't want to come across as if I'm against investing efforts to mitigate climate change. But in the real world, it ultimately comes down to trade-offs. So I agree with the premise that eventually, if unabated, climate change will likely cause "bad" outcomes. Apropos to this thread, though, is the definition of "bad". And from what other commenters have shared, there is large uncertainty of both the "low" and "high" temperature change models out to about 2070 or so.
In other words, even if the circumstances meet the definition for a "high" temperature change it may result in the same outcome as if it were a "low" temperature change, but the mitigation efforts would likely be drastically different. In a world where the solution is trade-offs, mitigating for one scenario over the other comes with real consequences. The point I'm trying to get at here is that I think uncertainty has to be a larger part of the conversation when we're talking about competing risks, especially when that uncertainty is relatively high. While uncertainty is a central part of a scientific discussion, my hesitancy about even bringing this up is that I also recognize that highlighting uncertainty is also a tactic of bad-faith actors to undermine any reasonable conclusions.
Rougly said, the chaos you are talking about is averaging out over larger spatial and temporal scales. The errors in climate models are coming from
A) necessary simplifications (we can only resolve the earth to a scale of a few kilometers or so and need to use subgrid models to approximate processes that happen on smaller scales such as cloud formation) and
B) unknown or not well enough known parameters and model behavior and
C) Unknown input quantities (most prominent: future man-made CO2 emissions)
There is thus quite some disagreement between different climate models[1] and uncertainty is sometimes reported based on the amount of disagreement between these models.
This is a great explanation, thank you. If I'm reading that chart correctly, out to 2060 or so, the uncertainty is high enough that both high and low temperature change scenarios overlap, but the overall risk is still moderate to high, is that right?
I think with how slow evolution happens, bad is anything that isn't the status quo. Yes, some species that are more adaptable will survive and could even thrive as competitors die off, but many more species will go extinct. It's hard to imagine any path here (at least on a short to medium term timescale) where biodiversity increases. And given that biodiversity is what got us to where we are, I think it's easy to agree that it's a good thing, so anything that threatens it is bad.
> All that said, I don’t think we have the computational models to predict what happens when you increase the temperature on earth for a century.
This definitely seems true. As a layman it seems like this is a classic case where chaos theory comes into play. Even tiny errors in our projections will lead to wildly different outcomes, so the only thing that we can say for sure is that we don't know. That's scary.
> And given that biodiversity is what got us to where we are
Mass extinctions also is what got us to where we are. If dinosaurs were still around when humans started to evolve, it might have been a Bad Thing.
Many species are supposed to go extinct, all the time. That's is how nature and evolution works. If we become extinct, then it paves the way for human++. This is neither good nor bad, it's just how life has evolved for billions of years. I think if we try to stop this and maintain status quo, that is ethically and morally wrong.
> Many species are supposed to go extinct, all the time.
True, but what are called "mass extinction events" actually took place over tens of thousands of years, which is "quick" when talking about geological time. We're potentially talking about a mass extinction event taking place over hundreds of years. The problem is that's a long time compared to a human lifespan, but an extremely short time from a geological standpoint. We have nothing from the past to analyze what the effects of this exceedingly fast extinction event will be - including whether it will lead to such ecological collapse that complex land animals such as humans can continue to exist. We simply don't know. One would think we should proceed with caution, but instead we're hitting the accelerator.
There are several effects of climate change that are undeniably "bad" for human civilization. Rising sea levels that wipe out coastal communities. Increased intensity of the biggest storms. Temperatures in some areas of the globe exceeding human tolerance for ever lengthening periods in the summer. Coral reefs dying off.
Even with a few silver linings here and there we should be doing what we can to reduce and even reverse climate change.
* Rising water temperatures decimating marine life
* increased temperature swings, including higher highs. The ways things are going, there are going to be vast areas which become uninhabitable by humans as they are today in places with tens of millions of inhabitants like Iraq, Pakistan, India.
Those are prety obvious, already in progress, and universally bad.
Change is bad because change can be catastrophically expensive. Civilizations don't die because they couldn't adapt, it's because they couldn't afford the cost of adapting, or because their entire society was predicated on a certain set of conditions that ceased to exist.
We take a lot of stuff for granted, like regular rainfall patterns in certain areas, that would be impossibly expensive to replace with technological solutions.
I think it's less that it's on the whole "bad" and more that it's bad because we spent the last few hundred years, trillions of dollars, and billions of years worth of personpower building our infrastructure based upon the current climate.
You don't drive economic growth by rebuilding infrastructure that already existed, but now in the wrong place.
You might "create jobs" that way in the general sense of stimulating an economy by borrowing against future monies, and that may be helpful in smoothing out a business cycle or avoiding a negative feedback loop, but "creating jobs" is only useful when the economy is understimulated (which it isn't at this particular moment, though I'm sure it will be again at various times between now and say 2100).
You increase the size of the economy, rather than just smooth out the business cycle, by increasing the net productivity of the population.
But that requires energy and materials which, if not managed properly, will make the problem even worse. Politically speaking, the biggest challenge to us is mass migrations may be required in order to adapt to the changing climate. Such migrations are rarely peaceful.
But then you inconvenience incumbents who expect to be able to retire to Florida on the value generated by capital that was allocated without regard to the impact that humans have on the planet's climate.
> That's not to say that some things about climate change aren't beneficial
It seems like on the net the changes are beneficial to a more productive biosphere - if they were happening on the scale of hundreds of thousands of years. Instead things are changing on the scale of decades and life won't have time to adapt. Delicate ecosystems are having a hard time.
As someone who has lived in both environments, high wet bulb temperatures suck way more than high arid temperatures. Sure, the latter can feel like living in a hair dryer but cooling is actually quite efficient. The former is just oppressive and is way more taxing on any AC. The moment you go outside everything is just covered in a sheen of sticky humidity.
Nordic countries like Russia, Canada and Scandinavian countries will benefit a lot from a warmer climate while equatorial countries will suffer the most.
I don't think there's any proof, just projection and speculation, that the overall net result will be bad. For much of human history, the equator has been the Goldilocks zone while the poles have been uninhabitable. If that were reversed, humans would adapt. It only feels scary because we're used to the equator norm and take it be the natural state of affairs, whereas there's nothing objectively natural about that.
Change is always scary. Trying to preserve something when change is inevitable is the mistake.
This is hyperbole. The entire world's population is only 8 billion, very small on the scale of "billions". And it's unlikely given the timescale on which things occur. As patches of the Earth become uninhabitable, humans will migrate to other areas, as they have multiple times in the past.
A proximal cause of the Syrian civil war is drought [1].
> Factors contributing to social disenchanment in Syria include socio-economic stress caused by the Iraqi conflict, as well as the most intense drought ever recorded in the region.[
This has led to half a million deaths, and the migration of 6 million refugees has caused political fractures in several developed nations.
The world is not set up for mass migration on the scale that will be needed if regional agricultural productivity changes unpredictably, even on the scale of decades. I could easily believe that a larger number of these events could compound into millions of famine deaths and a conflagration of military conflicts. 1+ billion deaths is well within range if global food logistics break down or a general military conflict is triggered.
On a more positive note, maybe we can stave off the long-term effects if we're able to develop and deploy a world-wide carbon capture technology. We are living in the Anthropocene after all!
Large parts of India and Pakistan will become uninhabitable in the next few decades. A billion people will be impacted just from there... throw in people from North Africa and South Europe facing droughts and all the related conflicts around them, and yes, billions sounds legit.
So, the mass migrations required to respond to climate change will present no problem? That's interesting seeing as how HN is hosted in a country having a major political party claiming its being "invaded" from its southern border. I doubt that country will suddenly become very welcoming as the climate situation deteriorates.
You don't think increased volatility in weather and storms is bad? I would love to hear how increased uncertainty over next year's growing season, floods, storms, etc would be a good thing.
It's not like deserts become green with calm weather...
I'm saying that thinking things won't change is bad. Change is an inevitable result of progress. Folks who want to reduce change want to slow progress down to "a manageable speed." And of course, no two individuals can agree on what that speed is. There are some for whom any forward progress is too much, so they'll never agree. That's why it's a mug's game, not worth playing.
If death of the species lies anywhere, it's in stagnation. As soon as we stagnate, we will start to die. That's the fundamental lesson of nature.
The way we're going to prevent unnecessary climate change is to progress beyond historic methods of energy generation, transportation, contruction, etc. rather than stagnating and just sticking with what we know how to do. The only people I see promoting stagnation are those with a large financial stake in legacy industries who see recent technological advancements as a threat to their bank accounts.
I'm not against change, I'm against change in a bad direction. I don't want democracies to change into autocracies. I don't want peace to change into war. I don't want the equator to change into a place that's too hot to live in, creating a lot of suffering and refugees and political instability in colder countries that have to receive refugees.
I do want good sources of change, like the GHG-decoupled economic growth we've been seeing, and technology and science breakthroughs.
How is global warming progress? Or are you saying the consequence of progress is massive amounts of pollution, and that anyone trying to stop said pollution is out there to stop progress?
Nothing is indicating to me that we are actually progressing. What I'm seeing is stagnation (we keep doing the same stupid things).
Progress to me would mean fewer problems, not more.
This particular change is not inevitable. Humanity as a whole would adapt, but individual humans on the order of millions and billions would needlessly suffer and die during the centuries of adaptation.
> The climate change of nature is still overwhelmingly more apparent than the human part at least regarding the CO2
Sorry. We know that to be false. No one is debating that, if left to its own devices, Earth is in the process of warming since the last ice age. That's a scientific fact. Earth would be warming even if humans weren't around.
What's also a scientific fact is that humans are accelerating that warming trend - and that's a problem. If the Earth were warming up on its own, it would do so much more slowly, and ecosystems would have lots of time to react. This has happened several times over Earth's past.
The difference now is humans are accelerating the warming. We can find no evidence of any other time in the past 100 million years of Earth warming up faster than it is now. We're limited to 100 million years (give or take) because that's the limit we can measure Earth's past climate. It's the slope of that temperature gradient that's the issue and humans have increased that slope, mostly by our dumping of CO2 into the atmosphere.
All this article "proves", as you say, is what we've known all along: by some measure climate change means some things will get better, other things will get worse. In the aggregate we expect things to get worse.
Younger dryas event like 12,000 years ago.
Looking at the jungles I don’t think planet is warm enough to benefit wildlife.
Time to get out of an Ice Age! yolo x)
The earth moves in milankovitch cycles around the sun which are a mayor contributor to warming and cooling cycles.
The ice core data shows also that increases in CO2 concentration followed after the temperature rose first which could correspond to the milankovitch cycles. The greenhouse effect takes places which leads to faster temperatures rises and humans are definitely contribution to that, which might already have changed how the world will look in the future.
Could youn link me to the record temperature rising right now in the last 100 million years please?
> The earth moves in milankovitch cycles around the sun which are a mayor contributor to warming and cooling cycles.
Yes, and that is extremely well-known. As are solar cycles. We have a pretty solid understanding of the natural cycles affecting climate. That's how we're able to assess humankind's impact on climate change above and beyond the natural variation.
We also well know that CO2 is released with rising temperatures in different systems and absorbed with falling temperatures. As mentioned before the ice core data shows exacly this a release of CO2 after a temperature increase. One could argue that it's a false correlation between temperature and CO2 especially since we talk about a concentration of 0.04% CO2 in the atmosphere. But that are just talking points I don't know the answers but seemingly you know the truth and ignore a conversation.
> The world was wrong to expect that climate change would trigger rapid and widespread desertification in the world’s arid lands
The science never said that. It was popsci, magazines and attention brokers that pushed that narrative. A warming world looks like Jurassic park, not Mad Max, but that doesn't sell, so they had to make it scary to sell it, hence the desertification narrative.
In this case the "greening" is not mutually exclusive with "Mad Max". One of the major points of the article is that the greening arid areas are also highly vulnerable to brush fires. CO2 is captured temporarily but then released back into the atmosphere again every time it burns.
Exactly, if you look at it from a thermodynamic standpoint a warming world means increased evaporation which leads to increased rainfall. There's simply more water in the air. So the threat isn't so much expanding deserts as it is more severe flooding events.
These effects can already be seen with many insurance companies abandoning low lying states like Florida and Louisiana. There are few instances of people more willing to put their money where their mouth is than insurance company actuaries.
The even more annoying fact is that the whole global warming crisis is BECAUSE of that thermodynamic effect. With increased CO2 alone, if we emit as much as we could, would only warm the Earth 1C at the most. CO2 has a narrow band of light that is obstructs, and once that is filled, there no more heat it can trap. The scientists believe that global warming will be as high as it will because of the positive feedback loop a little warming from CO2 causes with water vapor(which is a more potent greenhouse gas): you heat up 1C, which means more water evaporates, which means more heat trapped, which means more water evaporates etc.
If it wasn't for more water in the atmosphere, just CO2 warming, there would be no Global Warming crisis, it would be just a blip. And still, somehow people widely believe we'll overall be in desert-like conditions?
Desertification is largely man-made and caused by land degradation - clearing forests for agriculture, using the land irresponsibly, then moving on.
Sure some plains may be burning more green, but those plains were once rainforests.
The place I grew up - South Devon - was once a temperate rainforest. Yet the landscape I know (and thought was beautiful) is fields of grass and shrubs. The Moors. It would almost certainly return to being a rainforest if not for the active management (grazing and controlled burns). It's funny that that landscape looks very similar to the picture in the article despite being in a very different part of the world.
Someone needs to throw the lever on solar radiation management. It's half-assed in the extreme, but I don't see any other options now. If I was in charge, I'd do it.
Of course you're right, and it is quite apparent to me that we will not sort it out; there isn't even a "we" that's really in charge of the global atmospheric CO2 level - it seems like an emergent phenomenon of our civilization. I guess you get used to it after awhile, and it probably helps that I never wanted to have children.
HN has an extreme challenge in discussing high-conflict issues. I've pointed this out myself (see: <https://news.ycombinator.com/item?id=30376111>), and it's one of my major frustrations with the site. I do agree with you, strongly, that finding effective ways to break through this communication deadlock should be helpful.
That said, I've also found that the most effective way to counter this is not:
- Complaining, snarking, or even substantively mentioning voting trends. Among other issues, this goes specifically against HN guidelines (<https://news.ycombinator.com/newsguidelines.html>), and even where arguably defensible such comments tend to draw downvotes and flags, largely for the reasons given in HN's guidelines: they make boring reading (and discussion). There's also the fact that HN tends to sort out bad voting / bad comments eventually, though as with most online discussion sites it's strongly influenced by initial comments. That's another reason your top-level comment here was likely flagged and hard: it simply doesn't help resuscitate the discussion.
- Point-by-point rebuttal of myths and falsehoods. "Fisking" (<http://catb.org/jargon/html/F/fisking.html>) might have some validity in scientific argument, though as Einstein noted, if an idea is truly wrong, it takes only one sufficient rebuttal (<https://hsm.stackexchange.com/a/3485>). Cutting to the root of a specious argument is far more effective in my experience.
What I've done, to varying degrees of success, where I see a discussion going off the rails is to take the time to craft a top-level comment addressing what I see as a key, substantive, or under-discussed point, with the hopes of steering discussion back on track. It's not always successful, but it often is, even where I feel that I'm arriving late in the game. Key is to not reply to earlier comments (which amplifies them), or to address downvotes or other noxious behaviours. What I suspect is that there are enough readers of HN who are seeking the sort of comment I'm writing that even late contributions can substantively swing discussion. They key is raise the issues or arguments you think are being underrepresented. That's more work than a casual dismissal, but also far more valuable to HN as a whole.
And of course, climate change has been politicised out the wazoo. Downvoting the bullshit is key, though naturally the bullshitters employ a similar tactic. If this seems egregious, the proper response is message the moderators at hn@ycombinator.com raising the question of possible shilling or voting manipulation. Mods can step in, and HN's ultimate behaviour is a mix of moderation actions by members, staff moderators, and a fair bit of programmatic manipulation. Administrative mods are the ultimate backstop, but they are neither omniscient nor omnipresent and often take actions only after having been contacted directly.
An example of editing a comment of mine after some initial downvotes. I entirely ignored the downvote issue, and merely clarified my intent: <https://news.ycombinator.com/item?id=40673847>
And a rare case of a direct refutation (initially posed as a request for sources / clarification, also on a climate-adjacent topic as it happens). Turns out the OP was sharing some long-debunked bullshit disinfo: <https://news.ycombinator.com/item?id=40664837>
That's the problem with a simplistic climate story. Climate change is chaotic. The deserts may go green while the oceans die. Increased storms threaten your house. That's not to say that some things about climate change aren't beneficial, it's that, on balance, most of climate change is bad, at least from a peaceful human civilization perspective.