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SSJ_naruto_2003 posted:Most of the time the 95th probably doesn't equal extinction Is there any models where the 95th percentile is extinction?
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Dec 21, 2017 03:34
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Owlofcreamcheese posted:Is there any models where the 95th percentile is extinction? bau
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Dec 21, 2017 03:54
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Owlofcreamcheese posted:Is there any models where the 95th percentile is extinction? Well what R.I.M. was talking about was climate change's "long tail". See:  Where the statistical analysis of climate models come out with some really severe outcomes at the extreme. I'm not sure that's human extinction, but a 8-10C world looks radically different from the one we live in, and not in a good way. But that graph is quite old, and over the past ten years or so people have realized that when you analyze the data using Bayesian methods the long tail disappears, and this can be replicated using other methods. Additionally, we have decades of warming data, and they track to a moderate ECS almost exactly. It's gradually become a mainstream, if not the consensus, view. ECS is 3±0.5, and we don't have to worry about extreme variance on the upper bound. https://dotearth.blogs.nytimes.com/2013/02/04/a-closer-look-at-moderating-views-of-climate-sensitivity/
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Dec 21, 2017 03:57
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Thug Lessons posted:Where the statistical analysis of climate models come out with some really severe outcomes at the extreme. I'm not sure that's human extinction, but a 8-10C world looks radically different from the one we live in, and not in a good way. It's tiresome how every step everyone has to add their own ratcheting up. Like the model scientists present wasn't enough so it has to be the 95th percentile, but then by the next post that isn't enough so it's some new thing where it's human extinction, then I'm sure the next person will say it's the end of all life on earth. Because I guess the actual original horrific outcomes weren't spicey enough for death porn? So it's just a new thing every post oneupping whatever the last person said?
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Dec 21, 2017 04:05
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pure bullshit strawman you smug fucks tell yourselfs
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Dec 21, 2017 04:09
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Owlofcreamcheese posted:It's tiresome how every step everyone has to add their own ratcheting up. Like the model scientists present wasn't enough so it has to be the 95th percentile, but then by the next post that isn't enough so it's some new thing where it's human extinction, then I'm sure the next person will say it's the end of all life on earth. Because I guess the actual original horrific outcomes weren't spicey enough for death porn? So it's just a new thing every post oneupping whatever the last person said? Well yeah it's a culture problem in this thread. If you say climate change will cause the earth to explode no one will argue with you except me.
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Dec 21, 2017 04:09
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white sauce posted:Someone better tell these folks about corporate profits! I just want to throw it out there, it as been about as unseasonably warm in Moscow/Western Russia. There might not be even real snow on the ground for New Years (which is a bit bonkers.)
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Dec 21, 2017 04:19
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Thug Lessons posted:Well what R.I.M. was talking about was climate change's "long tail". See: I wouldn't go too far with this kind of reasoning, as of course models can't account for or predict things we don't yet understand. Saying we "don't have to worry" has to come with a lot of caveats. Modeling isn't wizardry and we shouldn't put undo confidence in it. There is so much we can't know about the future, which can be frightening at times, but also means we always have reason to hope.
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Dec 21, 2017 04:25
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Thug Lessons posted:Well what R.I.M. was talking about was climate change's "long tail". See: For as much as you talk about ECS I'm not sure you even understand what it actually is. ECS is the amount of warming that we would expect due to a doubling of CO2 alone from the GHG feedback of CO2 alone. You don't seem to understand that this doesn't consider other climate feedbacks that may be positive or negative. You don't seem to understand that permafrost methane release does not logarithmically increase like CO2 as it is doubled[1]. You don't seem to understand that sea level rise from marine ice cliff instability does not logarithmically increase as CO2 is doubled[2]. You don't seem to understand that straospheric water vapor GHG feedbacks do not logarithmically increase as CO2 is doubled[3]. You don't seem to understand that warm deep water upwelling to WAIS from ozone depletion does not increase logarithmically as CO2 is doubled[4]. You just don't seem to get that even if ECS tends to 0 as CO2 concentration increase toward +inf it's possible for total warming, SLR, or biosphere effect to not also tend to 0 at the same rate. It doesn't. Get it through your head. You don't seem to get that I freak out about WAIS collapse due to temperature forcing putting zonal wind flow in a goldilocks zone that increases warm water upwelling specifically to WAIS. You don't seem to get that PIG and Thwaites are buttresses that prevent the rest of the WAIS from collapsing. You don't seem to get that uncertainty from feedbacks not modeled by CMIP5 or EMICs don't include feedbacks that research indicates produce uncertainty larger than the 5-95 ranges of our current models. And if you just don't seem to get it, I really don't know what to say other than actually read the literature. Maybe you should spend some time understanding why our models have uncertainties and what those uncertainties are. It's not hard, climatology papers are surprisingly accessible to anyone who has a background in calculus, stats, and a bit of research methods. [1]: e.g. https://www.nature.com/articles/ncomms15872 quote:In the ESAS, ice scouring penetrated as much as 10 m into the sediments, and where surface sediments were underlain with free gas, strong ebullition to the water column through the scours was observed (Fig. 5d). Ice scouring likely provides an important mechanism, not only for unroofing shallow gas accumulations (Fig. 6a), but also for allowing gases to avoid anaerobic oxidation due to removal/disintegration of the uppermost sediment layers, where anaerobic oxidation of CH4 occurs within the sulphate-reduction zone. [2]: https://www.nature.com/articles/s41598-017-04134-5/figures/4 [3]: https://link.springer.com/article/10.1007/s00382-016-3231-3 quote:We find that a uniform 1 ppmv (0.5 ppmv) SWV increase (decrease) leads to an equilibrium global mean surface warming (cooling) of 0.12 ± 0.05 °C (−0.07 ± 0.05 °C). Sensitivity experiments show that the equilibrium response of global mean surface temperature to SWV perturbations over the extratropics is larger than that over the tropics. [4]: http://onlinelibrary.wiley.com/doi/10.1002/2015GL064314/full quote:McCusker et al. [2012] showed in a set of idealized simulations that when the global average temperature is stabilized using a stratospheric sulfate layer that counteracts growing CO2 concentrations, an anomalous poleward intensified zonal wind stress on the Southern Ocean remains that causes upwelling of warmer subsurface waters to the level of ice sheet outlets. Warmed subsurface ocean waters that destabilize marine ice sheets may introduce threshold behavior in ice sheet mass loss [Notz, 2009] such that ice sheet loss, and hence SLR, becomes nonlinear with increased warming [Joughin et al., 2014].
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Dec 21, 2017 04:32
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As far as what we will likely learn next: A lot of effort is being invested into the hydrological cycle such as how water vapor feedbacks work in both the troposphere and stratosphere. I expect uncertainty in this domain to close a lot over 2018 and 2019. We will see further advances in WAIS modeling but uncertainty will still be high due to the extreme nonlinearity of the problem. ESAS methane release will continue to be the sleeping giant that we ignore because it is not being investigated outside of a small group of researchers. Stratospheric ozone effects will be heavily researched as we start to consider what will happen if we go with the spray n pray option for blasting a bunch of sulfates into the air.
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Dec 21, 2017 04:36
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Notorious R.I.M. posted:For as much as you talk about ECS I'm not sure you even understand what it actually is. ECS is the amount of warming that we would expect due to a doubling of CO2 alone from the GHG feedback of CO2 alone. This is entirely wrong. ECS does account for the most important feedbacks, namely water vapor, clouds and surface albedo. If ECS just included the pure radiative forcing of CO2 it would have a value of about 1. It is based on a doubling of CO2, but incorporates feedbacks to determine how that will translate into surface and ocean warming. I could go through this giant post of yours and try to correct all the errors, but it's obvious you just don't know what you're talking about. I suggest you read this chapter from the 4th report and then just study the concept generally for a couple weeks and then come back, hopefully enlightened and on my side. https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-6-2-3.html
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Dec 21, 2017 04:41
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Please correct all the errors
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Dec 21, 2017 04:47
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Squalid posted:I wouldn't go too far with this kind of reasoning, as of course models can't account for or predict things we don't yet understand. Saying we "don't have to worry" has to come with a lot of caveats. Modeling isn't wizardry and we shouldn't put undo confidence in it. Well climate modeling has a lot of uncertainty. 2-4C is a big gap and those outcomes resolve into radically different worlds. But the reason climate scientists are so confident in it is that it's a very reliable method. It's based on physics, which is very good at making predictions, and it has a spectacular track record of predicting the past four decades of warming. We can't logically rule out higher ECS values... but we can rule them out statistically at a 95% confidence interval.
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Dec 21, 2017 04:50
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Notorious R.I.M. posted:Please correct all the errors There's no reason to. You're a crank who doesn't understand how climate sensitivity works. What you're posting about has nothing to do with climate science.
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Dec 21, 2017 04:51
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i predict that everybody reading this post will be dead by the year 2097
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Dec 21, 2017 04:53
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Thug Lessons posted:There's no reason to. You're a crank who doesn't understand how climate sensitivity works. What you're posting about has nothing to do with climate science. Sorry, I'll correct my post to say "CO2 forcing" instead of "CO2 feedback", that was an error. Now correct my post. Oh wait, you're just a whiny little liberal who thinks telling people not to eat meat is undemocratic and authoritarian and thus evil.
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Dec 21, 2017 04:54
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Thug Lessons posted:Well yeah it's a culture problem in this thread. If you say climate change will cause the earth to explode no one will argue with you except me. As if there will be a solar system left for an earth to explode in, am i rite
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Dec 21, 2017 04:57
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seaweed farms
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Dec 21, 2017 04:57
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Notorious R.I.M. posted:Sorry, I'll correct my post to say "CO2 forcing" instead of "CO2 feedback", that was an error. Now correct my post. Oh wait, you're just a whiny little liberal who thinks telling people not to eat meat is undemocratic and authoritarian and thus evil. You don't have to correct your post. You just don't understand how ECS estimates are determined. You think they don't account for water vapor, (you explicitly mentioned this as a nonlinear feedback unaccounted for by ECS), which they absolutely do. So instead of correcting your post do some reading so you can understand how climate sensitivity works. Maybe this is a better place for a beginner to start rather than the IPCC chapter: http://www.realclimate.org/index.php/archives/2013/01/on-sensitivity-part-i/ There's a part 2 btw, linked in the first paragraph.
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Dec 21, 2017 04:59
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Thug Lessons posted:Well climate modeling has a lot of uncertainty. 2-4C is a big gap and those outcomes resolve into radically different worlds. But the reason climate scientists are so confident in it is that it's a very reliable method. It's based on physics, which is very good at making predictions, and it has a spectacular track record of predicting the past four decades of warming. We can't logically rule out higher ECS values... but we can rule them out statistically at a 95% confidence interval. Here is literally a 2017 paper that puts the 90% CI on ECS at 1.7 - 7.1C: https://www.nature.com/articles/nclimate3278 quote:Using model-based estimates of how climate feedbacks will change in the future, in conjunction with recent energy budget constraints produces a current best estimate of equilibrium climate sensitivity of 2.9 °C (1.7–7.1 °C, 90% confidence). Like seriously, you're too loving stupid to read a paper that's not from the 4-year-old IPCC. You should abruptly reduce your carbon footprint to 0 imo. (USER WAS PUT ON PROBATION FOR THIS POST)
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Dec 21, 2017 05:00
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Notorious R.I.M. posted:Here is literally a 2017 paper that puts the 90% CI on ECS at 1.7 - 7.1C: Yes, there are still some people that hold out for a long tail. But most of them don't. I've read about this paper before and it's mainly an attempt to reconcile (lower) global energy budget methods with (higher) model estimates, not an attempt to prove a long tail. It's an interesting paper, and suggests that we can't rely on the global energy budget methods to hold out for a very low ECS, but it doesn't go very far towards proving your point. e: Here's some discussion on the paper (and another similar one) for those that are interested: http://www.realclimate.org/index.php/archives/2017/07/climate-sensitivity-estimates-and-corrections/ http://www.realclimate.org/index.php/archives/2017/08/sensible-questions-on-climate-sensitivity/ Thug Lessons fucked around with this message at 05:13 on Dec 21, 2017 |
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Dec 21, 2017 05:11
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And I know reading is hard, but you seemed to miss the word "stratospheric" before water vapor in my post. Weird how your link only talks about tropospheric WV. It's listed as a not-understood high-uncertainty feedback in another section! https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-6-3-1.html#box-8-1 quote:In the stratosphere, GCM water vapour response is sensitive to the location of initial radiative forcing (Joshi et al., 2003; Stuber et al., 2005). Forcing concentrated in the lower stratosphere, such as from ozone changes, invoked a positive feedback involving increased stratospheric water vapour and tropical cold point temperatures in one study (Stuber et al., 2005). However, for more homogenous forcing, such as from CO2, the stratospheric water vapour contribution to model sensitivity appears weak (Colman, 2001; Stuber et al., 2001, 2005). There is observational evidence of possible long-term increases in stratospheric water vapour (Section 3.4.2.3), although it is not yet clear whether this is a feedback process. If there is a significant global mean trend associated with feedback mechanisms, however, this could imply a significant stratospheric water vapour feedback (Forster and Shine, 2002). Thanks for giving me a link about the upper troposphere though. Stratospheric water vapor is the component that is heavily linked to methane forcing from the Arctic which has high uncertainty. Notorious R.I.M. fucked around with this message at 05:43 on Dec 21, 2017 |
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Dec 21, 2017 05:11
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Thug Lessons posted:Yes, there are still some people that hold out for a long tail. But most of them don't. I've read about this paper before and it's mainly an attempt to reconcile (lower) global energy budget methods with (higher) model estimates, not an attempt to prove a long tail. It's an interesting paper, and suggests that we can't rely on the global energy budget methods to hold out for a very low ECS, but it doesn't go very far towards proving your point. And here is more commentary on these findings that both lower the upper-bound ECS and raise interesting points: https://www.earth-syst-dynam-discuss.net/esd-2017-119/esd-2017-119.pdf quote:Since IPCCs fifth assessment report (AR5) there has been an improved understanding of the causes of the differences in estimates of climate sensitivity from climate models and observational based methods, directed to two main reasons. First, recent analysis of time-varying feedbacks in AOGCMs simulations from Coupled Model Intercomparison Project Phase 5 (Proistosescu and Huybers, 2017;Armour, 2017;Andrews et al., 2015) have indicated that in most AOGCMs the net feedbacks become more positive over time as a new equilibrium is approached. This is most likely due to evolution of the pattern of sea surface temperature increase in the Pacific and Southern Ocean and associated cloud feedbacks. quote:According to Richardson et al. (2016), there is a general bias in the surface temperature records since water heats slower than the air above and due to undersampling in fast warming regions (e.g. the Arctic). Taking both effects into account, Armour (2017) shows that previous estimates of ECSinf of about 2.0°C are consistent with estimates of ECS of 2.9°C from climate models. quote:Using only the Levitus2000 series for OHC for the total ocean column (case D), the ECSinf 90% C.I. was shifted to lower values with a range from 1.5 to 4.6°C and the range shrunk compared to case C. The historical measurements of ocean 10 temperatures are sparse (Abraham et al., 2013), with large differences between the datasets. The temporal structure of the reported uncertainties differs, and the full uncertainties are often not assessed. Hence, relying on only one OHC series and its reported uncertainty may underestimate the observational uncertainties and hence overestimate the certainties in the estimated OHC with implications for the ECSinf estimate. The last comment is interesting because it shows a strong uncertainty in reported ECS based on the ocean heat content dataset(s) used and suggests that a misunderestimation of observational OHC uncertainty causes us to overestimate the certainty of ECS. Edit: And this has an easy policy take-home message everyone can agree on: Fuckin fund atmospheric observational research. Notorious R.I.M. fucked around with this message at 05:45 on Dec 21, 2017 |
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Dec 21, 2017 05:42
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australiar posted:seaweed farms jellyfish farms
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Dec 21, 2017 08:40
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beef farms 
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Dec 21, 2017 09:05
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treerat posted:jellyfish farms jellyfish algae aquaponics
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Dec 21, 2017 09:06
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can we use seaweed to grow insect protein
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Dec 21, 2017 09:28
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quote:You should abruptly reduce your carbon footprint to 0 imo.
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Dec 21, 2017 14:18
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treerat posted:China enacts cap and trade for power plants Relatedly, here's an interesting magazine article from Quartz summarizing the state of carbon capture and storage R&D in China. It probably doesn't say anything people here didn't already know or could guess ie there are serious challenges to get CCS widely adopted, but I did find the author's struggle to actually visit a trial CSS site amusing. Some key quotes: China is the acid-test for a technology that could save the world from catastrophic climate change posted:... As the article mentions, China generates ~70% of it's power from coal and can't afford to replace it. CCS could actually help the country meet it's emission reduction targets, but there's no getting around that a non-CSS coal plant is simply more profitable than a CSS plant. Additionally it has to be adopted very rapidly for China to meet its emissions targets, I believe that 2020 capture target corresponds to a factor of ~50 increase in capacity in 2 years! It will require direct state intervention (like the proposed cap and trade system?) for the technology to ever become widespread. Which gets to opaqueness issue, who knows what the Chinese govt will actually do?
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Dec 21, 2017 15:11
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They'll keep burning coal (and if given the alternative natural gas) just like every other major industrial nation on this stupid planet. CCS as a technology is a zero-sum game if everyone isn't doing it and can only become the norm through broad international agreements which aren't happening.
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Dec 21, 2017 15:17
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Thug Lessons posted:When you can convince a majority, or even a significant minority, of climate scientists to accept a 95th percentile case as the most probable one, I'll start taking it seriously. But the reality is that so far, mid-range models have predicted global warming with startling accuracy. There was a report recently that the most accurate model predicts more warming than the average, but it also predicts just 0.5C more warming than average under an RCP8.5 scenario - which, of course, is nowhere anywhere near the 95th percentile. Evil_Greven posted:Speaking of things falling into the sea: Evil_Greven posted:For some estimates, yes.
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Dec 21, 2017 19:12
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MiddleOne posted:They'll keep burning coal (and if given the alternative natural gas) just like every other major industrial nation on this stupid planet. CCS as a technology is a zero-sum game if everyone isn't doing it and can only become the norm through broad international agreements which aren't happening. I have to admit you've confused me. In what sense is CCS technology zero-sum instead of net cost? It actually makes coal power expensive and places an economy at a competitive disadvantage unless everyone else is using it too. Definitely agree it would be nice to have an international framework to allow this kind of coordinated action. Especially one with the world's 2nd largest nation-state polluter participating instead of fully embracing a dementia-inspired spite for future people.
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Dec 21, 2017 19:51
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Evil_Greven posted:Startling accuracy in the mid-range, huh? I'm talking about climate modeling. I don't make such claims for projections of ice sheets, precipitation patterns, and so on, because they're simply not as accurate.
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Dec 21, 2017 20:02
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Thug Lessons posted:I'm talking about climate modeling. I don't make such claims for projections of ice sheets, precipitation patterns, and so on, because they're simply not as accurate. The second quote is about temperature, however.
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Dec 21, 2017 20:12
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Nocturtle posted:I have to admit you've confused me. In what sense is CCS technology zero-sum instead of net cost? It actually makes coal power expensive and places an economy at a competitive disadvantage unless everyone else is using it too. Definitely agree it would be nice to have an international framework to allow this kind of coordinated action. Especially one with the world's 2nd largest nation-state polluter participating instead of fully embracing a dementia-inspired spite for future people. It's the competitive advantage that makes it zero-sum. The economics losses you make for adopting CCS will appear as gains for another economy that didn't adopt through the wonders of international markets and competition. Theoretically, by increasing the marginal cost of production you're effectively decreasing your own countries production. In an open economy that means imports from a country with a non-CCS burdened cost of production will replace your domestic production. CCS is also unique from an economic perspective for having no net benefits from wholesale adaption. Everyone just gets to enjoy slightly more expensive coal energy with no comparative gains or losses for anyone. Climate-wise is another matter but really you'd be better off just trying to price the actual externalities instead of adopting CCS. Both will have the end-result that coal stops being used if there is an alternative and the other is way less convoluted. Pricing the externalities can even have the effect of making the market adopt CCS on its own if CCS actually becomes good enough! MiddleOne fucked around with this message at 20:42 on Dec 21, 2017 |
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Dec 21, 2017 20:40
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Evil_Greven posted:The second quote is about temperature, however. I can't really see what's going on in that graph. But if you're saying climate models have underestimated warming, you're incorrect.
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Dec 21, 2017 20:45
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For clarity remember there are two kinds of CCS point-source CCS and ambient-capture CCS. Point-source CCS is just a gimmick to burn more coal. Ambient-capture CCS is currently a gimmick too but could theoretically be combined with a carbon-free grid to produce net-negative emissions at a high energy cost.
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Dec 21, 2017 20:55
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As ambient-capture CCS is about as realistic as solving global warming through nuclear winter I just assume whenever someone mentions CSS that they're talking about point-capture.
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Dec 21, 2017 21:33
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MiddleOne posted:As ambient-capture CCS is about as realistic as solving global warming through nuclear winter I just assume whenever someone mentions CSS that they're talking about point-capture. That's mistaking the role ambient-capture could play. It isn't about "solving" global warming all on its lonesome, its about giving us a chance to keep reducing harms after we've shifted our economy to net-zero carbon-equiv. emissions.
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Dec 21, 2017 21:42
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Trabisnikof posted:after we've shifted our economy to net-zero carbon-equiv. emissions. 
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Dec 21, 2017 21:56
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