How hot will our planet actually get? Climate scientists try to answer this question by evaluating the “climate sensitivity”. And if you’ve watched the recent Sabine Hossenfelder, you may be left with the impression that climate change wasn’t much to worry about… but now it is. So I’m here to explain what the evidence is actually showing us, and why the situation is a little more nuanced than Sabine’s commentary may have suggested. And crucially I break down how climate scientists arrive at a number for the crucial “climate sensitivity”, to give us a sense for how much global warming we’re in for.
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Piers Forster https://twitter.com/piersforster
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Zeke Hausfather https://twitter.com/hausfath
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==MORE INFO==
Sabine video: https://www.youtube.com/watch?v=4S9sDyooxf4
My video on landmark climate sensitivity paper: https://youtu.be/7tMAkhQCJ48?si=XxdpXJP2zOA3x4ko
Nature Comment on hot models: https://www.nature.com/articles/d41586-022-01192-2
Hot models too hot historically: https://esd.copernicus.org/articles/11/737/2020/esd-11-737-2020.html
… and for the last “ice age”
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021MS002776
Explanation of climate sensitivity: https://www.carbonbrief.org/explainer-how-scientists-estimate-climate-sensitivity/
The epic study on climate sensitivity: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019RG000678
Weather forecast to validate model: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019MS001986
Associated comment piece: https://www.nature.com/articles/d41586-020-01484-5
Why such forecasts tests should be carried out: https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.23
The James Hansen paper: https://academic.oup.com/oocc/article/3/1/kgad008/7335889
Critiques of it:
https://twitter.com/hausfath/status/1720098321161957761 (check the replies too)
https://michaelmann.net/content/comments-new-article-james-hansen
https://www.eenews.net/articles/james-hansen-is-back-with-another-dire-climate-warning/
https://www.washingtonpost.com/climate-environment/2023/12/26/global-warming-accelerating-climate-change/
Do climate protests work: https://journals.sagepub.com/doi/10.1177/2378023120925949
IEA net zero roadmap: https://iea.blob.core.windows.net/assets/9a698da4-4002-4e53-8ef3-631d8971bf84/NetZeroRoadmap_AGlobalPathwaytoKeepthe1.5CGoalinReach-2023Update.pdf
==CREDITS==
Sabine photo from Sabine Hossenfelder
Ice core clip from The Conversation
Ocean visual and temperature projection from Nasa
Greek floods by Weather events
source
44 comments
"Wow Adam what an amazing video, but where's the message from your sponsor??" – – Great question! I'm not interested in selling you things you don't need, so I don't activate ads or have product placements. Videos like this one are made entirely with the support of incredible patrons like Jannick over on patreon. Join the team of CliMates over here: https://www.patreon.com/ClimateAdam
In your video, your message might come across as minimizing the concerns of viewers who are worried about climate change. While highlighting a positive outlook can be valuable, focusing primarily on 90% of the video reassuring people against overreacting could unintentionally downplay the urgency of the situation. Given the significant challenges we face, like the lack of strong action at COP28, it's important to strike a balance between optimism and the reality of the situation. Perhaps considering more nuanced communication that acknowledges concern while still offering solutions and hope could be more effective in motivating viewers to take action.
The key point Sabine is making here is not "the hot models are correct", but rather: "there is more reason for doubt the conclusion the hot models are incorrect is… correct". And when we are talking about a topic where the consequences of underestimating the risk are potentially catastrophic, this is not just an academic debate. Even a small probability the hot models are correct is worth paying a lot of attention to. This is a point made very well by Taleb: even small probabilities for catastrophic outcomes need to be taken much more seriously than small probabilities of middling outcomes.
So, Sabine is not wrong. You just dumbed down what she said and tried to include some thoughts of what people might think when they watch her video. However, that is not relevant. And you discredited the urgency to act, which I does a disservice to the goal.
Instead, you praise glueing oneself to random things in the total illusion it would affect change somehow. Which is ridiculous. Anger people enough, and they will do exactly the opposite of what you try to achieve. Like block ambulances and the firefighters on the road or people trying to get to work. Stupidity, if I ever saw some.
Anyway. The point is, that models that predicted or reconstructed past data with high accuracy do not necessarily predict the future as good. That was Sabine’s point. And it looks, as if for future predictions, the hotter models deliver a better fit, even though the are not as good for past data. That model that can be used for weather prediction also, takes into account cloud effects better than others, so it has potential to deliver on the problem of the influence of these better than other models. This could be used to create a more sophisticated model that includes this.
Sabine has a history of sensationalist BS and "hot takes" on subjects outside her personal field of expertise and she's long since lost any credibility with me. She's repeatedly taken public stances on subjects she has not only no expertise on, but also no expertise to tell how crackpot her scriptwriters for the subject are, and as a result she's been blatantly wrong on a number of topics, and utterly ignorant of the nuances of the positions she's advocating for (or seemingly aware that she IS advocating for a controversial stance sometimes). Her response to being called out on these things is inevitably confrontational and ultimately resorts to an appeal to authority of "I'm the science expert here, I know good and bad science when I see it, me smart, you stupid".
Jim Hansen was the "scientist" who conspired with Sen. Tim Wirth (D) to schedule the climate hearing on the statistically hottest day of the year in Washington DC. They also interfered with the committee room's air-con the night before to ensure it was not working during the hearing. Finally all the press coverage, with powerful lights and a packed chamber ensured the entire hearing was staged ( as in staged ) in an excessively hot room. Thus we see that the whole thing was rigged from the outset by political activists, NOT objective science.
Carbon capture doesn't work today, and it will not work tomorrow. Sure, keep working on it lest we have a breakthrough that makes it actually viable, but as it is, there are no signs that carbon capture will be even the tiniest part of the solution. It doesn't scale even in hypothetical ideal conditions. The only way to get rid of CO2 in the atmosphere is to not emit it to begin with.
Climate models do NOT model cloud cover from "basic physics" as is so often claimed. They are simulated by guestimated "parameters": so-called expert opinion. Which is still basically opinion not maths or physics and is open to personal bias wherever that may lie.
Despite being publicly a very active climate activist, here is what James Hansen's 2002 paper says about models and sensitivity:
"The bottom line is that, although there has been some narrowing of the range of climate sensitivities that emerge
from realistic models [Del Genio and Wolf, 2000], models still can be made to yield a wide range of sensitivities by altering model parameterizations."
IOW, modellers can produce whatever climate sensitivity they wish by tweaking these poorly constrained "parameters". The idea that this is all based on "basic physics" is a lie. The key processes such as evaporation, advection and cloud formation are NOT based on known laws of physics, they "tumed" to whatever the model team thinks they "should" be. Despite the billions of dollars and all the super computers, it all comes down to guessing reasonable values which give a result which fits you expectations or political agenda.
So, here’s the deal. The scientists are always wrong, and always right, just not always at the same time and timeline.. Sabine is a star. But “NOBODY “ is correct all the time, and Sabine is no exception, the fact she has changed her mind on global warning is a perfect example. A scientist is a calculator and analyzer of data. But, “Nobody” can know “ALL” data. So a scientist is at best a “good guesser” of the best knowledge they have read or aligned to. And that latter part, “aligned to” is very relevant.. if you only look at the data that suit your bias, then your answer will carry the same bias. If you’re trying to prove black people are more violent than white people, and use American jail demographics, then your data will back up your thesis. But if you look at jails in Holland, then you will find a white bias, and this will hurt your thesis, so you don’t use it. Scientists at best should be renamed as “Opinionated best guessers”.
This guy is vaguely annoying he’s too chirpy and cheerful for a start but when he keeps saying so what Sabina is saying I’m sorry I don’t need to be patronized. I know what she’s saying because I listen to the bloody video myself!!!
A video is very straightforward and easy to understand and does not require the interpretation of someone who says he has a PhD from God knows where.
I do not care about his PhD. I care about my relationship between the video I watched and my capacity as an intellect to understand it without having an interlocutor.
I thought he was going to add something, but he’s actually added nothing. Sadly, YouTube is full of this sort of thing.
Sabin point is a very simple one and it is that the behavior of clouds, which suggest a higher sensitivity at an equilibrium point for a given level of carbon dioxide in the atmosphere, appears to offer a much greater predictor of weather than the use of the behavior of clouds, which is previously been used to support a lower level of climate sensitivity for the same level of carbon dioxide present in atmosphere.
Obviously, it is not proof tends to support the data and the assertions based on the data that will being widely discussed 15 or so years ago, and which were panned by most climate scientists, who had tenured professor ships for whatever reason they chose to pan them.
Also, the use of ‘scary’ is rather silly as a word here. In days gone by we would’ve used that as a descriptor when speaking to children and not to adults but now anything that is not planned straightforward and in no way threatening you at all is called ‘scary’
Very useful in the therapeutic state, where everyone is treated as a thin skinned infant to be handled with kid gloves.
Please do better next time, but I do doubt that I will be watching you
When they halfed the effectiveness of co2 in models they need to double the sensitivity….
I believe that climate change is a real issue, but man I despise those kids throwing soup at art or creating a mess on a highway. Most people already have problems in their day to day lives to deal with that sh|t. Its so narcissistic and stupid. "Civil Disobedience" is just making things worse, people will never have empathy with that kind of behavior.
How I would work out these issues is watch YouTube videos like these 🙂
To estimate climate sensitivity, I would use theoretical and computer models, meteorological and ice core measurements, and green nail polish.
Hey really a great video! Two questions that still confuse me: – There is a hypothesis that the models with a low climate sensitivity can reproduce the past well because they underestimate the cooling effect of aerosols – what's the truth in that?
– In addition, the current models do not seem to take into account certain feedback loops, such as the greatly increased methane emissions from wetlands – what about this?
I can tell you one thing, civil disobedience like this, that first and foremost inconveniences the normal people will basically only do harm to the cause. I resent people that waste their energy and time, and MY energy and time with useless non constructive actions like that. I haven't met a single person in favor of it that hasn't been completely sold on the extremist premise to begin with. If these people were working on actionable solutions rather than virtue signaling and harming the economy we could shave a few years of our climate goals. But they prefer to hurt the economy, which will reduce free resources that could be allocated to climate change and waste their own time which reduces productivity.
hot
Nah man, I'm not watching another 18 minute long video.
Good arguments & we love Sabine, but the bottom line is, We just dont know! We are guessing & using computer generated models to try and improve our guesses, but there are too many variables & too little data to work with to get a clear picture, but we do think we are getting better at it too. I think that sums it up.
We were exiting the Mini Ice Age about 140-150 years ago. Of course the planet is warming. It is still cooler than 600 BC or the Medieval period. Between the sun, its phases, the carbon dioxide produced by the planet (greener earth is, more CO2 naturally produced), variation in orbit and position of earth, earth will warm and cool without the existence of man. We should be more worried about that big rock that may be kissing earth in the 2060s. Something about life ending, but no one wants to be an alarmist about that, but global warming is an OK subject.
BTW, wasn’t all that long ago – earth time – that earth had 4000ppm CO2 and yet here we are in an unusually temperate period of earth’s history of 410ppm, and scientists comparing earth to Venus with its 96.5% CO2 atmosphere. Oh joy.
It seems that the assumption of both videos is that climate sensitivity is a constant, but I'm wondering if there is logic and/or evidence for or against this. In other words, could the value be a variable? I have no idea. Perhaps my question stems from mere confusion on my part. Basically, I'm wondering if the sensitivity number itself could be subject to nonlinear factors, leaving us with the possibility that, even if we figure out the sensitivity for the past 100 years, we might still be shocked by what happens 20 years from now to the relative impact of carbon levels. Nature seems to have a lot of catastrophic tipping points. In any case, the bottom line is the same: We need to stop dumping so much pollution into the environment.
Thanks for some reasonableness. Here in the USA we experience protests and activism to raise awareness on issues where the underlying assumptions are provably false. I go about wearing a helmet to protect me from the sky falling in (according to Sabine "Henny Penny"). I guess I won't live long enough to see the Statue of Liberty half under water, nor to see the seas boil in 300 years according to Sabina's channel.
@climateadam can you suggest what is best climate model ????
Some climate-related actions are happening too often and too intensely.
Is your nail polish carbon neutral?
I understand that a professional climatologist needs to understand these models. However, we laypeople have a different role, and I think prudence should be part of it. I see no comment in the video about how prudence should help guide the viewer. Related to prudence are statistics, and the probability of certain outcomes. Both prudence and judgements about probability are subjective and I'd trust the subjective judgement of the majority of climatologists over the subjectivity of the layperson.
Now let's get even more practical and notice that, as far as I can tell, the actual outcomes on temperatures and sea level have been consistently worse than predicted. This fact must then figure in how prudent we want to be, and it might affect what we'd judge the probability of which climatologists have more accurate predictions over others. Finally, when you consider the fact of the tremendous benefits green energy generation and use has over fossil fuels regarding human health and environmental destruction, why would anyone want to make the extremely imprudent claim that since these models aren't exact we have no real need to eliminate fossil fuels?
Bottom line, let's role up our sleeves and make the green energy transition as fast as possible. It will undoubtedly improve human health, the health of ecosystems; it's prudent, and it's probably the best thing to do. To me it's a no-brainer and I don't think we need any models to tell us that.
Ever since Sabine made her poorly-researched and biased video about transgender people I’ve stopped listening to her content. I’ve realized that there are people out there with more interest in the facts and less of a focus on grabbing attention and I prefer to listen to those voices. Thank you for being one of them! Somehow I was not already subscribed to your excellent channel but I am now!
It's so great to get all the extra context and subtleties added to Sabine's video. What an amazing example of science communication, accessible but not dumbed down at all. Thanks for your service Adam!
Hmm… I would imagine that the three most important variables would be… Greenhouse gas levels, corresponding temperatures, and their relationship over time as calculated using the Navier-Stokes equations maybe? Regardless, awesome video!
So, basically one model is likely to be more predictive than all the others but we don't know which one. That's not very reassuring!
The Hansen paper is an eye opener. Figure 2 shows the close correlation between CO2 and temperature in the paleo data for the last 800k years, with CO2 ranging from 200ppm to 300ppm and temperature ranging over 10 degrees C. We are already up to 420ppm which suggests we are comprehensively doomed unless we can somehow get it back down to a more normal value before the planet notices! Much more likely we will keep pumping CO2 until we reach the 1000ppm level or more.
2.9-3.6 degrees Celsius with a K?
Why bother to call it "Climate Scientist" when the
word "Grifter" is so much simpler and more accurate.
Charlatans and gaslighters like Michael Mann have been totally exposed, their deception and lies exposed by their own emails being released.. instead of answering the questions these emails raised they took the absurd position that they would not dignify stolen emails? So Mann goes about his climate alarmist charade, writes copious articles that are published in mainstream magazines and trade journals (I stopped reading Scientific American after the umpteenth time they featured this outright deceiver's articles) he does so as if he has never been unmasked and his motivations exposed.
Regardless of the model you choose to trust do you really want to play with Pascal's wager. If the hot model is wrong and we still act as if it's right the outcome is still better than the other way around.
I find it extremly arrogant to think that we as a species and civilisation that exists for like, what? 5000 years? And in general since like 200,000 years? And our POTENTIAL impact on the climate of the Earth since what? 200 years? How old is the earth? 4.54 billion years? 200 years not even a blink of an eye worth of time compared to the lifetime of Earth. Lets say we have an negative impact on climate since 2000 years, besides the fact that we as a species exist, which cant be changed somehow.
2000 years = 0,00004405% of the Earths lifetime…. let that sink in first, before you people cry about that WE destroy the planet or whatever. Planet Earth will still exist when we will be long gone as a species. Also, to think that Earth wouldnt have these climate changes without us, is extremly arrogant in my eyes.
Brilliant! Thank you so much for putting this together and explaining it so well.
There's too much fudging in the paleoclimate data. CO2 sensitivity from the past 150 years is pretty low, about 0.8 degrees C, probably because the data is too hard to hide. Also, those models are completely crammed full of fudge factors.
While I respect ClimateAdam's attempt at being reasonable, it's a little like averaging Astrology and Astronomy together to find out what is most likely true. Those sources of information do not have equivalent credibility! Data obtained by direct measurement of physical quantities like temperature deserves the most respect.
Right or wrong, no conclusion should be arrived at to stop or reduce efforts for further research for more equitable resolutions. Unfortunately that will require planet-wide cooperation… Is that possible/impossible? Nevertheless, it is obvious to me, after 73 years of living in Earth's embrace, that it is definitely changing. And either Humanity will accept that there are changes, and adjust to those changes, INSTEAD of forcing the Earth to adjust to our demands. (Fat chance, I know.) 🙁
Good job dismissing all her major points and editing out their context. Also, compiling all the evidence we have is obviously not the best course of action if some of that evidence has been gathered through erroneous processes, which is the central proposition of Sabine's video.
she is worth listening to, this twit just loves the sound of his own voice
Hmmm…
Suppose I can't blame you too awfully much for attempting to bump up your subscription base on Sabine Hossenfelder's coattails, so to speak. Pretty sure she wouldn't mind, either. 😊
If you want the most accurate predictions on Global Warming (otherwise known as Hell on Earth), look no further than the scientific modeling conducted by Exxon Mobil beginning decades ago, before they went on their massive Big Tobacco-like Lie and Deny campaign to ensure that the $$$$$ kept flowing into their trousers.
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