6 ms·
FWIW my personal assessment is that this acceleration is both real and largely out of our control. Models in the past did not attempt to account for non-anthrop
by sulam 7mo ago
FWIW my personal assessment is that this acceleration is both real and largely out of our control. Models in the past did not attempt to account for non-anthropogenic carbon emissions, but as we experience further warming, most especially in the Arctic, feedback loops and tipping points mean that this (carbon emissions caused by “natural” processes) are becoming more evident. This is especially sensitive because a large proportion of such emissions are methane, which is a much more powerful greenhouse gas vs CO2, albeit with a much shorter expected effect time once airborne (~12 years). Consider also that warming is not uniform and the polar regions are warming significantly faster (3x) than lower latitudes, making permafrost melting a very significant climate tipping point. The last point I’ll mention is not about non-anthropogenic emissions but rather absorption. The world’s oceans have been a significant absorber of CO2 however that process is sensitive to temperature and is less effective as the planet warms, not to mention acidic ocean waters prevent shell formation, which is a minor but meaningful carbon sink all by itself.
I’m of the opinion that direct air capture is the primary escape hatch we have for not hitting 3 or even 4C warming in the next 100-200 years, which mean major dieoffs in warm latitudes, even for humans, due to exceeding wet bulb limits. Oh and roughly 65M of sea level rise as the planet shifts to a snow/ice-free mode.
- pinkmuffinere 7mo agoNo offense, but internet opinions are a dime a dozen -- do you have some special experience / credentials in this area? The arguments you provide are all just the sort of thing that PhD students would study, and incorporate into their models. I'm inclined to believe the experts, but if you _are_ one, and are saying with authority that these effects are missed, that is a much more interesting story.
- hendler 7mo agoThe question is not if the commenter is an expert, but if they are correct. The claim that some models didn't take larger systems into account is also because an expert in the arctic wasn't an expert in oceans. And the expert in biodiversity isn't an expert in food supply chains. Expertise isn't the question. Instead it is - do all of us who are non experts (all of us) have enough expert data to have a systemic understanding of an accelerating trend?
- cyanydeez 7mo agoOn the internet the default pisition is not true/untrue; its, why should I acknowledge you? If you are still trying to gauge truth before this, you are poisoning your mental heuristics. Thats why propaganda are ao effecfive: you can be told something is either, and it can still be effective. Humans and LLMs are similar: the separation between input and commands is not a hard barrier. So, back to GP: CLIMATE CHANGE is reversible. It just depends on whether we are talking about socipecnomics or physical processes.
- pinkmuffinere 7mo agoYa, I agree, but I am not familiar with the intimate details of present climate models, nor am I planning to be. I can't/won't directly evaluate whether the argument they present is correct. But if _they_ are familiar with the intimate details of present climate models (ie, if they are an expert), I will tend to trust them more.
- sulam 7mo agoI’m not a modeler but I have directly asked modelers if clathrates, permafrost melting, wildfire incidence and ocean drawdown responses to warming was incorporated in the major models. 5 years ago the answer was no. Today the answer might be yes, but this is not really the point I’m trying to make. It’s really that we should expect to see acceleration in warming as the natural environment responds to anthropogenic (“forced”) climate change.
- mlyle 7mo agoThe models don't consider these because there's considerable uncertainty as to the size of these effects and potential countervailing forces of similar magnitudes. The fact is, for all of these other secondary effects etc... we just don't know. It's too complicated of a system. So as a result, we've got a prediction of something between "somewhat bad" and "catastrophically-is-an-understatement bad" with a maximum likelihood estimate of "really really bad."
- 7mo ago
- sulam 7mo ago2 years ago this was hard won knowledge, searching for papers and then putting it all together in survey form for analysis. Today I can tell you: feel free to ask Deep Research or another LLM you trust to do that work for you, generating citations along the way. You can convince yourself vs me having to convince you. It will take about 15 minutes.
- pinkmuffinere 7mo agoFor better or worse, I don't trust an LLM to give me a correct answer in this space. But you've kindof dodged the question by recommending LLM's -- do you have special experience / credentials in this area?
- Yhippa 7mo agoIf they said yes, would you blindly trust them? They told you to "do your own research" effectively and you punted. That would arguably be a more reassuring path for you I assume.
- pinkmuffinere 7mo agoTruthfully, because they dodged the question I am now a bit suspicious of everything they say. It just seems a bit deceitful. I explicitly called out the dodging not because I wanted to hear from them after they'd dodged it, but because I want to make it clear to GP that their answer is not sufficient, and highlight to others that they maybe shouldn't trust GP. If they had answered my first question in the affirmative (something like "I am a researcher at X institute on this topic"), ya, I think I would have trusted them.
- sulam 7mo agoI don’t type fast on my phone, so you’re getting responses as I can give them. I think I’ve answered your questions sufficiently to draw your own conclusions at this point. Feel free to ignore me. Physics doesn’t care.
- 7mo ago
- nostrebored 7mo agoSurely the children churning out papers in a memey field, with no real special insight into computational modeling, are the real ones to trust! Their papers are in Nature! Ridiculous take, and you’d know that the OP was correct if you cared enough to know what researchers were actually saying. Climate arguments devolve into appeals to impact claimed by authorities rather than any examination of what they’ve said.
- transcriptase 7mo agoWould a PhD student incorporate something into their model that flipped their results from agreeing to disagreeing with the premise that has not only practically become a religion, but forms the foundation for more and more funding flowing into their field each year? Would they really want to risk being basically excommunicated from their area of research for daring to provide ammo to “climate change deniers”?
- m4x 7mo agoThis is rather disingenuous. It can be hard to overcome momentum in research, but most researchers would be giddy with excitement if they could show our (extremely disturbing) forecasts regarding climate change are wrong and that things are much rosier than expected. I also suspect you would find easy funding from existing climate change deniers. There is no shortage of well-heeled folk in that space. Do you have a chip on your shoulder regarding research? You're begging the question by stating it is conducted in a "practically religious" way. Ask whether that's true before you question the effect it would have on somebody's behaviour.
- deepsun 7mo agoRe carbon capture -- we can cut trees and dump them in "carbon storage" places like the bottom of some water bodies where due to lack of oxygen no rotting happens, like peats and e.g. Black Sea. And grow new trees in their place of course.
- adrianN 7mo agoIt’s difficult to scale this to the levels we would need to make a difference.
- lazide 7mo agoThe more likely candidate is mineral based, because yes trees are hard to scale this way.
- zdragnar 7mo agoDepending on the tree, freshly cut wood can have anywhere from 1:3 to 2:1 ratio of water to actual wood fiber. So, unless we want to remove a massive amount of fresh water from the ecosystem, we also need to invest energy in drying out the wood well below natural humidity levels (transport to a desert maybe?) on top of electrifying what is currently a diesel and gas heavy industry (cutting and transporting logs with heavy machinery). There's definitely lower hanging fruit for getting C02 out of the cycle.
- MarkusQ 7mo agoDumping wet wood--even very, very wet wood in a lake and sinking it to the bottom does not "remove a massive amount of fresh water from the ecosystem". It does not remove any fresh water from the ecosystem.
- zdragnar 7mo agoSinking wood into a lake won't remove the carbon unless you have a very deep lake, and you'd need many, many of them to have any impact on the CO2 levels whatsoever. The scale of wood that would need to be harvested is far beyond dropping some logs in a lake. They need to go into a deep enough pit where the methane produced from anerobic breakdown won't reach the atmosphere. The conditions that created the lignite coal and peat simply aren't that easily reproducible, especially with large volume of wood (rather than ferns over thousands and millions of years).
- 01100011 7mo agoWhat about solar shades? Seems like a relatively quick and easy way to regulate solar input. It's nice too because you can quickly remove it if necessary.
- ACCount37 7mo agoOnly becomes viable if you have things like Starship online and fully operational, with launch rates at the level of Falcon 9 today. At the minimum. Still a more viable option than bringing greenhouse gas emissions into the negatives globally, by the way. But that's a low bar. Nuking the ocean floor is probably a better call.
- casey2 7mo agoI'm confident that pushing everyone involved with Starship into the ocean would be a better and faster and more ethical green transition.
- tremon 7mo agoHow long would a single cargo-load of shades have to be operational just to offset the amount of CO2 emitted by its launch?
- post-it 7mo agoReducing sunlight to the surface means we lose solar power effectiveness and we need to use more power for artificial lighting to grow plants.
- altruios 7mo agoMost of the surface of the earth is covered with water... What if we cover the ice caps, and cover parts of the ocean instead of messing with grow cycles of plants on land... No reduction in solar power, no artificial lights to grow plants. What effects might that have on ocean life? (below a certain depth - probably nothing, so surface ocean life is what we need to look at). Just my two cents... we got plenty of surface area we can cover and potentially not affect much at all for day to day for animals, plants, and humans.
- jgalt212 7mo ago> Oh and roughly 65M of sea level rise as the planet shifts to a snow/ice-free mode. Where is this new figure coming from? It seems about 60X what's being published elsewhere.
- toxik 7mo agoIf all glaciers and ice sheets on Earth melted, sea levels would rise roughly 65–70 meters (about 210–230 feet). It’s worth noting that a full melt of Antarctica alone would take many thousands of years even under extreme warming scenarios, so this is more of a thought experiment than a near-term risk. Current projections for this century focus on partial contributions, with estimates ranging from roughly 0.3 to over 1 meter of rise by 2100 depending on emissions pathways.
- marssaxman 7mo agoThat's been known for a long time - it just hasn't been considered a likely scenario. It's the rise we'd expect if all the ice on Greenland and Antarctica were to melt: https://sealevel.nasa.gov/understanding-sea-level/global-sea-level/ice-melt/ https://sealevel.nasa.gov/understanding-sea-level/global-sea...
- pfdietz 7mo agoAlbedo modification (stratospheric aerosols) seems much cheaper than direct air capture, as a stopgap.
- adrianN 7mo agoThat unfortunately doesn’t help with ocean acidification.
- ryeights 7mo agoWe simply drop a giant tub of baking soda into the ocean every now and then.
- Fishkins 7mo agoThus solving the problem once and for all https://www.youtube.com/watch?v=VW66EX75jIY https://www.youtube.com/watch?v=VW66EX75jIY
- loeg 7mo agoSo what? You still save millions of lives.
- culi 7mo agoThe research isn't there. Jury is still out on whether the long term consequences are a net benefit. In the end you're talking about increasing emissions for a temporary decrease in temperatures. And the chemicals we have that are good candidates for albedo modification are quite toxic. Today more than 10% of deaths globally can already be attributed to air quality
- pfdietz 7mo agoIf India is experiencing large scale mortality from warming, they aren't going to give a damn about your concerns. They're just going to inject aerosols into the stratosphere.
- wing-_-nuts 7mo agoRelying on DAC is putting our fate in the hands of a technology we've never deployed beyond some pitifully small pilot projects, and expecting that we're going to be able to deploy that at a larger scale than we've deployed any technology since electricity itself. We're going to have to resort to geoengineering alright, but it's gonna likely be stratospheric sulfate injection given how cheaply that can be done. Is it ideal? Nope. Better than global warming itself? Time will tell.
- marssaxman 7mo agoThe prospect that the future we're headed for will be one where the survival of civilization (and much of humanity) depends on a massive, ongoing industrial process of upper atmosphere pollution, in order to counteract the massive, ongoing industrial process of CO2 pollution we can't be arsed to rein in, leaves me feeling relieved to be mortal.
- wing-_-nuts 7mo agoI don't disagree. At this point, I'm thankful I never wanted kids.
- auntienomen 7mo agoIt's going to have to be a mixture of approaches. Stratospheric injection buys time for more holistic solutions.
- baq 7mo ago> major dieoffs in warm latitudes, even for humans, due to exceeding wet bulb limits my extremely pessimistic position is nothing will happen systemically even after the first few such events, and they'll take tens if not hundreds of thousands of lives. I hope writing this out jinxes it.
- zeryx 7mo agoAre you kidding? It will be Millions easily. It will just take 1 or two blackouts in wet bulb conditions to cause that
- wing-_-nuts 7mo agoYou saw our reaction to covid. Millions. It will take millions of deaths in a nuclear armed country. See 'The ministry for the future'
- fwipsy 7mo agoI generally endorse that book but I am not sure we are quite so short-sighted. What's necessary is for the people who have power (not just billionaires and politicians, but even the middle class in democracies) to feel that they are in danger. A heat wave with a million casualties might do it, but I'm not sure it's the only way.
- estimator7292 7mo agoWe are already far past the point of mere thousands of lives. Entire cities have been wiped off the map by floods. It will take millions, if not close to a billion lives before we get serious
- zahlman 7mo ago> Entire cities have been wiped off the map by floods. Could you name some?
- yoyohello13 7mo agoI wish it were different but I would not be surprised if it’s billions before anything changes. And even then there will be a major proportion of people that celebrate it as the second coming.
- pier25 7mo agoExcellent comment. I would only add two points. I think it's important to mention the effects we're seeing today are caused by the emissions from decades ago. Second, not sure if the paper in the OP touches this but we've reduced aerosols in the atmosphere. These previously were masking the effects of climate change by cooling the temperature.
- adolph 7mo agoThe paper states it adjusts for "ENSO, volcanic eruptions, and solar variations" and not (afaict) the changes in shipping bunker fuel that reduced atmospheric SO2 (if that is what you mean by "reduced aerosols"). Below is a summary of the topic for those who are unaware. I withhold any opinion of validity of mechanism or effect. Sulphur particles contained in ships' exhaust fumes had been counteracting some of the warming coming from greenhouse gases. Lowering the sulfur content of marine fuel weakened this masking effect, effectively giving a boost to warming.
- masklinn 7mo ago> Models in the past did not attempt to account for non-anthropogenic carbon emissions They're literally mentioned by the first IPCC report already.
- culi 7mo agoEarly IPCC reports, all the way up to AR5 basically threw their hands up when it came to permafrost emissions. They admitted we didn't have the necessary data yet and for the most part didn't account for it at all in their models Check out the 1.5C special report. Go to section 2.2.1.2, last paragraph says > The reduced complexity climate models employed in this assessment do not take into account permafrost or non-CO2 Earth system feedbacks, although the MAGICC model has a permafrost module that can be enabled. Taking the current climate and Earth system feedbacks understanding together, there is a possibility that these models would underestimate the longer-term future temperature response to stringent emission pathways https://www.ipcc.ch/sr15/chapter/chapter-2/#:~:text=Geophysical%20uncertainties%3A%20climate%20and%20Earth%20system%20feedbacks https://www.ipcc.ch/sr15/chapter/chapter-2/#:~:text=Geophysi...
- Someone 7mo agoThe claim being discussed is not that they didn’t account for it, but that they didn’t attempt to account for it. Reading that text, I think they did, but chose not to include it (I guess because they didn’t need to to make their point and, by not including it, avoided opponents from arguing about the validity of the result based on uncertainties in those models)
- culi 7mo agoI don't get the distinction you're trying to make. It seems to me they considered it, but did not even attempt to account for it. They admitted limitations of the data/research they had available. Their model explicitly does not attempt to account for it.
- lokar 7mo agoIs it fair to say they account for it, but don’t try to quantify if?
- mempko 7mo agoRegarding carbon capture, it will take more energy to capture the carbon than we burned putting it up there in the first place. Alan Kay, who actually did some systems work on the environment, explained it to me that the climate system is like an upside down coke bottle. It doesn't take much energy to tip it over, but it takes a lot more to put it back up. In other words, we shouldn't have tipped it over in the first place. We may not have the energy to put things back to a habitable place.
- danny_codes 7mo agoPhysically that’s not the case. Scaled up nuclear power could be had for $3-4B a gigawatt/h. We waste say $1T a year on basic things, like not having universal healthcare. So a simple policy change would let us build about 300 reactors a years, after some scaling period. The excess energy can be used to turn C02 back into oil. It’s not technically that difficult, we just chose to waste money on stupid things and rich people toys instead. Energy abundance is simply the choose to build nuclear power plants at scale
- mempko 7mo agoSince the industrial revolution we've emitted about 1.5 trillion tonnes of CO2. Direct air capture requires roughly 1,500 kWh per tonne, so recapturing all of it would take around 2,250,000 TWh. Current global electricity production is about 30,000 TWh/year. That's 75 years of the entire world's electricity output just for capture, before you even convert it back to fuel, which costs even more energy. And thermodynamically you can never break even: we only extracted maybe 30-40% of fossil fuel energy as useful work, but reversing the dispersal of CO2 from 420ppm in the atmosphere fights entropy all the way back. It will always cost more energy to put back than we got taking it out. As for the nuclear numbers: Vogtle, the only recent US build, came in at ~$16B/GW, not $3-4B. The world started construction on 9 reactors total in 2024. The all time peak was ~30/year in the 1980s. 300/year has never been close to reality. Average build time is about 9 years per reactor. I'm not anti-nuclear but you can't hand-wave your way past thermodynamics and industrial scaling with "it's just a policy choice."
- philipwhiuk 7mo ago> I’m of the opinion that direct air capture is the primary escape hatch we have for not hitting 3 or even 4C warming in the next 100-200 years Why is it always never 'burn less fossil fuels'. Anything but the oil company bottom line huh?
- culi 7mo agonobody will champion degrowth because it means less profits
- wing-_-nuts 7mo agoWe could cease burning all fossil fuels tomorrow and we'd still have to resort to geoengineering. Read the IPCC projections. All of the ones that keep us below 3c require 'negative emissions'. That's code for DAC, a technology that we've only ever deployed to small pilot projects, deployed more widely, more quickly, than we've deployed any technology ever. TLDR: We're gonna have to use sulfate injection until we can transition our economy
- zargon 7mo agoYes. And if we don't also stop burning fossil fuels then we'll never even break even.
- imglorp 7mo ago> direct air capture is the primary escape hatch We MUST MUST MUST stop burning things. Stop it. - We are still mining and burning coal. This is incomprehensible. US, AU, etc Eg: https://www.nacoal.com/our-operations https://www.nacoal.com/our-operations - We are still subsidizing oil to around $1T/year, not counting oil wars. Yes it will take some grid and storage upgrades (US) and continue to embrace renewables. It would be cheaper than the oil subsidy. Otherwise it doesn't make sense to put CO2 into the air with one hand and take it out with another.
- crystal_revenge 7mo agoThis is why it's clear we will never do anything to slow the progression of climate change. By far the most effective an immediate solution to limiting the damage of climate change is to simply to keep fossil fuels in the ground. People talk about the economic pain of doing this, but that economic pain is nothing compared to the impact of unmitigated climate change. Even though this would be painful, it is also by far the easiest and fastest to implement solution. It would take fantastically more time and resources to scale up direct air capture (even if it existed in a scalable format today) to come anywhere near addressing this problem. > Yes it will take some grid and storage upgrades (US) and continue to embrace renewables This is not exactly true, we would have to experience global economic collapse in order to reduce our fossil fuel use. 80% of energy is not spent on electricity globally and this is non-electricity usage is where most of the fossil fuels are consumed and this drives most of the global economy. There's a good reason there are multiple wars being fought over for oil.
- jimnotgym 7mo agoGenuinely not being snide, I really do not know. Is it possible to produce steel on industrial scales without coal? I know early ironmaking (I live fairly close to Coalbrookdale!) used charcoal, but is that possible at a large scale?
- acdha 7mo agoIt’s complicated: https://news.mit.edu/2025/decarbonizing-steel-tough-as-steel-0611 https://news.mit.edu/2025/decarbonizing-steel-tough-as-steel... This is one of the stronger arguments for a carbon tax: if you can’t ignore externalities, people have strong incentives to use less (e.g. buying a car instead of an SUV or biking) and all of the alternative fuel and process work is going to be easier if the cost comparison is more even.
- WarmWash 7mo agoCan't wait until the arctic unwinds and releases massive amounts of methane into the air, then in the hot hell that earth becomes, all the fucking idiots saying "See I told those stupid liberals that the warming process was natural and not from my truck!!!1!1"
- mentos 7mo agoWhat if global warming is beneficial to keep the next ice age at bay?
- jpadkins 7mo ago> Oh and roughly 65M of sea level rise as the planet shifts to a snow/ice-free mode 65M seems a lot bigger than the 3.6mm/year rise we are seeing today (with +1.5C in warming already happening). Where did you read that we will get 65M of sea level rise with 1.5-2.5C more warming?
- frm88 7mo agoIt's the extreme scenario with all the earth ice melted, even Antarctica. Depending on the model chosen and acceleration this could happen between 2243 and 21861. http://sealevelrise.se/en/earth_slr65.html http://sealevelrise.se/en/earth_slr65.html.
- ant6n 7mo ago> I’m of the opinion that direct air capture is the primary escape hatch Great! That means we dont need to reduce emissions, cuz the magic bullet will just take care of everything. No need to change anything.
- zahlman 7mo ago> Oh and roughly 65M of sea level rise as the planet shifts to a snow/ice-free mode. Current rates of sea level rise are still in single digit millimetres per year (https://en.wikipedia.org/wiki/Sea_level_rise https://en.wikipedia.org/wiki/Sea_level_rise), so that would take millennia. If there's even enough ice in the caps to get that far. Pre-historically, vast ice sheets covered broad swaths of regions now considered "temperate" (per the famous XKCD, "Boston [was] buried under almost a mile of ice"); what remains is a tiny portion and it's simply hard to imagine that it could fill the seas to such an extent. If you have detailed calculations, please feel free to cite them. But my back-of-the-envelope reasoning: NOAA gives an average sea depth (https://oceanservice.noaa.gov/facts/oceandepth.html https://oceanservice.noaa.gov/facts/oceandepth.html) of 3,682 meters. You propose that this could increase by nearly 2%. But the density of water only exceeds that of ice by about 9% (via https://en.wikipedia.org/wiki/Ice https://en.wikipedia.org/wiki/Ice); the thickness of the https://en.wikipedia.org/wiki/Antarctic_ice_sheet https://en.wikipedia.org/wiki/Antarctic_ice_sheet is only about half that average sea depth; and it covers only about 4% of the water-covered area of the planet (14 million km^2 vs. 361 million km^2, per https://en.wikipedia.org/wiki/Earth https://en.wikipedia.org/wiki/Earth) which is not even all oceanic.
- sulam 7mo agoThis is a very common figure you can find much support for. Here’s one legitimate source: Ice Melt | Global Sea Level – NASA Sea Level Change Portal — https://sealevel.nasa.gov/understanding-sea-level/global-sea-level/ice-melt/ https://sealevel.nasa.gov/understanding-sea-level/global-sea...