I Was Worried about Climate Change. Now I worry about Climate Scientists.

Summary

In this video, the speaker discusses climate sensitivity and its critical role in understanding climate change. They highlight concerns about higher climate sensitivity values reported by recent models, which some climate scientists have dismissed. The speaker argues that this issue is underreported and crucial for government plans to combat climate change. They draw parallels to past scientific biases and emphasize the importance of accurate climate predictions. The video also promotes Planet Wild, an environmental initiative focused on restoring ecosystems, and encourages viewers to support their efforts.

Takeaways

• 🌡️ The 'climate sensitivity' is a critical model parameter that indicates how much the global average temperature will change in response to an increase in atmospheric carbon dioxide.
• 🔍 The speaker is concerned that the climate sensitivity might be higher than the range suggested by the IPCC, which could have significant implications for climate change mitigation plans.
• 🗣️ There has been a debate among climate scientists about the reliability of models that predict a higher climate sensitivity, with some arguing these 'hot models' should be given less weight in IPCC assessments.
• 🏛️ The speaker argues that the issue of potentially higher climate sensitivity has been underreported and is important for government planning to reach net-zero emissions.
• 🤔 Two common reactions from climate scientists are dismissed: one that climate sensitivity is irrelevant to the need to stop global warming, and another that variability in climate sensitivity predictions is normal.
• 🔎 The speaker criticizes the dismissal of high climate sensitivity models, likening it to a pattern in physics where new, unexpected measurements are initially rejected due to confirmation bias.
• 🧐 The comparison made by some scientists between different climate sensitivity values and the number of riflemen in a firing squad is criticized for being misleading and downplaying the importance of the rate of climate change.
• 🔬 The speaker highlights the importance of not underestimating uncertainties in scientific measurements and the need for scientific communities to be vigilant against confirmation bias.
• 🌳 The speaker introduces Planet Wild, an organization focused on restoring ecosystems and financed by community contributions, as an example of practical and realistic environmental action.
• 📹 Planet Wild is praised for its transparency, providing video reports of its missions to supporters, which is seen as a sign of respect and accountability.
• 💰 The speaker offers an incentive for viewers to join Planet Wild, covering the first month's membership for the first 200 people who sign up using a provided code.

Q & A

What is 'climate sensitivity' as discussed in the video?

Climate sensitivity refers to a model parameter that indicates how much the global average temperature would change in response to an increase in atmospheric carbon dioxide. It's a key factor in determining the rate at which climate change may worsen.

Why is 'equilibrium climate sensitivity' significant in climate science?

Equilibrium climate sensitivity is significant because it helps predict the long-term changes in global temperature due to increased carbon dioxide levels. It's crucial for understanding the pace of climate change and for formulating effective mitigation strategies.

What is the 'hot models' problem mentioned in the script?

The 'hot models' problem refers to a situation where some of the world's best climate models began to produce a much higher climate sensitivity than the average of previous models. This has led to debates among climate scientists about the reliability of these models and their inclusion in IPCC assessments.

What are the two main reactions from climate scientists regarding the underreporting of the 'hot models' issue?

The first reaction is that the climate sensitivity is a distraction and that we need to address global warming regardless of its exact value. The second reaction is that there are many papers published annually with varying climate sensitivities, suggesting that one should not focus on individual studies.

Why does the speaker argue against the idea that climate sensitivity is just a distraction?

The speaker argues that climate sensitivity is crucial for government plans to reach net zero emissions. If the climate sensitivity is underestimated, current plans may be inadequate, which could lead to more severe climate change impacts.

What is the issue with the comparison made by Zeke Hausfather and Andrew Dessler in their blog post?

The issue with the comparison is that it equates climate sensitivity with the size of the problem rather than the rate at which it worsens. The speaker argues that the rate of climate change is more critical for planning and mitigation efforts.

What is the concern raised about the reliability of climate models?

The concern is that climate scientists may have changed their interpretation methods after some models produced results that didn't fit their previous narratives. This could introduce bias and affect the accuracy of climate projections.

What is the example of the neutron's lifetime used to illustrate in the script?

The example of the neutron's lifetime is used to illustrate how scientific measurements can suddenly change, indicating that previous uncertainties may have been underestimated. This has implications for how climate scientists should handle new data that doesn't fit with older models.

What is confirmation bias and how does it relate to the handling of scientific data?

Confirmation bias is the tendency to favor information that confirms one's preexisting beliefs and to dismiss or scrutinize more closely information that contradicts them. In science, this can lead to a bias towards confirming previous findings, which may affect the objectivity of data analysis.

What is the speaker's stance on the current IPCC projections regarding climate sensitivity?

The speaker believes that the uncertainty on climate sensitivity is much larger than what the current IPCC projections suggest, indicating a potential underestimation of the risks associated with climate change.

What is Planet Wild and how does it relate to the speaker's environmental concerns?

Planet Wild is an environmental organization that focuses on restoring ecosystems and biodiversity through community-supported missions. The speaker supports their practical and realistic approach to environmental conservation and encourages others to join the community.

Outlines

00:00

🌡️ Climate Sensitivity Concerns and Misreporting

The speaker expresses concern over the potential underestimation of climate sensitivity, a critical model parameter indicating how much global temperatures could rise due to increased atmospheric carbon dioxide. They mention a recent shift in some top climate models predicting higher sensitivity than the IPCC's range suggests, which could mean current mitigation plans are inadequate. The speaker criticizes climate scientists for dismissing the importance of climate sensitivity in planning, arguing that it is crucial for governments' strategies to combat global warming. They also address the 'hot models' problem, where certain models predicting higher sensitivity were deemed unreliable, and suggest this issue has been underreported.

05:02

🔍 Confirmation Bias in Climate Science

This paragraph delves into the concept of confirmation bias, explaining that it leads individuals to scrutinize findings that contradict their beliefs while accepting those that align without question. In the context of climate science, the speaker suggests that this bias may have influenced the handling of new model results that conflict with established narratives on climate sensitivity. They argue that climate scientists have not adopted the rigorous methods used in physics to mitigate such bias, leading to a potentially skewed interpretation of climate models. The speaker emphasizes their belief in the significant uncertainty surrounding climate sensitivity and expresses concern that the climate science community may not be immune to the pitfalls of confirmation bias. They conclude by advocating for collective action to address environmental issues and promoting Planet Wild, an organization that actively works on ecosystem restoration.

Keywords

💡Climate Sensitivity

Climate sensitivity refers to the model parameter that quantifies the change in global average temperature in response to an increase in atmospheric carbon dioxide. It is pivotal for understanding the rate at which climate change may progress. In the video, the speaker expresses concern that the true climate sensitivity might be higher than what is suggested by the IPCC's range, which has significant implications for climate change mitigation plans.

💡Equilibrium Climate Sensitivity

Equilibrium climate sensitivity is a more precise term within the field of climate science that specifies the long-term temperature response once the climate system has reached a new equilibrium following a change in atmospheric carbon dioxide levels. The video emphasizes that this parameter is crucial for governments to formulate effective climate action plans.

💡IPCC

The IPCC, or Intergovernmental Panel on Climate Change, is an international body that assesses the science related to climate change. It provides policymakers with assessments and recommendations based on the latest scientific research. The video discusses the IPCC's role in setting the uncertainty range for climate sensitivity and the potential implications of this range being underestimated.

💡Hot Models

In the context of the video, 'hot models' refers to a subset of climate models that predict a higher climate sensitivity than the average of previous models. The term is used to describe a controversy within the scientific community, where these models' predictions are considered by some to be unreliable and should be given less weight in IPCC assessments.

💡Confirmation Bias

Confirmation bias is a psychological phenomenon where people tend to favor information that confirms their existing beliefs or values. In the video, the speaker suggests that confirmation bias may be influencing climate scientists' interpretation of model predictions, particularly when those predictions do not align with previously accepted narratives.

💡Neutron Lifetime

The neutron lifetime is an example used in the video to illustrate how scientific measurements can be subject to systematic errors and biases. Neutrons, stable within an atomic nucleus, have a known decay rate once isolated. The video points out that measurements of the neutron lifetime have historically jumped outside previous uncertainty regions, suggesting underestimation of measurement uncertainties.

💡Systematic Underestimation

Systematic underestimation refers to the consistent undervaluing or overlooking of certain factors or uncertainties in scientific measurements or models. The video uses this term to discuss how climate scientists may have underestimated the uncertainty in climate sensitivity, drawing parallels to similar issues in other scientific fields.

💡Planet Wild

Planet Wild is an organization mentioned in the video that focuses on practical, community-supported environmental restoration projects. The speaker highlights Planet Wild as an example of an initiative that actively involves supporters in tangible efforts to restore ecosystems and biodiversity.

💡Biodiversity

Biodiversity refers to the variety of life in all its forms and interactions within an ecosystem. In the video, the speaker discusses a Planet Wild project aimed at restoring a Caledonian woodland, emphasizing the importance of biodiversity in maintaining a healthy and balanced ecosystem.

💡Mitigation Plans

Mitigation plans are strategies or actions designed to reduce the severity or impact of a problem, in this case, climate change. The video argues that the accuracy of climate sensitivity estimates is critical for the effectiveness of these plans, as they inform decisions on how to reach net-zero emissions targets.

💡Community Contributions

Community contributions refer to the collective support, often financial, provided by individuals to fund projects or initiatives. In the video, the speaker discusses how Planet Wild is financed through such contributions, which enable them to carry out their environmental restoration missions.

Highlights

Climate sensitivity is a model parameter that indicates how much the global average temperature changes in response to an increase in atmospheric carbon dioxide.

Equilibrium climate sensitivity is crucial for determining the speed at which climate change will worsen.

There is a concern that climate sensitivity might be higher than the IPCC's uncertainty range suggests.

The 'hot models' problem refers to some of the world's best models predicting a higher climate sensitivity than the average.

Climate scientists have argued that these 'hot models' are unreliable and should be given lower weight in IPCC assessments.

The underreporting of the potential for higher climate sensitivity is a significant issue.

Some climate scientists dismiss the importance of climate sensitivity, arguing that action is needed regardless.

Government plans to reach net zero are based on expectations of climate sensitivity, making it a critical factor.

The comparison of climate sensitivity to the number of riflemen in a firing squad is criticized as misleading.

The issue with 'hot models' is that they were included in IPCC predictions until their results became undesirable.

Confirmation bias in science can lead to underestimating uncertainties and reinforcing prior beliefs.

Physicists have learned to avoid confirmation bias by deciding on analysis methods before looking at data.

Climate scientists have been criticized for changing their interpretation methods after undesirable model results.

The speaker believes the uncertainty on climate sensitivity is larger than current IPCC projections suggest.

The speaker, though not a climate scientist, has observed scientific communities reinforcing incorrect conclusions in other fields.

Planet Wild is an environmental initiative focused on restoring ecosystems through community contributions.

Planet Wild documents their missions with video reports, ensuring transparency and respect for supporters.

The speaker offers to cover the first month for the first 200 people signing up with the code SABINE.

Transcripts

A few weeks ago, I made a  video on climate sensitivity,  

explaining why I am worried about it. There have  now been a few reactions by climate scientists.  

I’d like to briefly comment on that, and add  something which I took out of the first video.

Just a brief recap of what we’re talking  about. The “climate sensitivity” is a  

model parameter that tells you how much  the global average temperature changes

in response to an increase in atmospheric  carbon dioxide. It’s the most important  

number to determine how quickly  climate change will get worse.

I should more precisely say that this parameter  is called the “equilibrium climate sensitivity”  

because there are several sensitivities in climate  science, and not all of them are model parameters.

The issue I was talking about in my  previous video is that this climate  

sensitivity might be much higher than  the IPCC uncertainty range suggests,  

and therefore also higher than most plans  to mitigate climate change assume. And  

I feel that given the relevance of this  possibility, it’s been very underreported.

What’s happened is that a few years ago, some of  the world’s best models began to produce a much  

higher climate sensitivity than the average of the  previous models. After that, climate scientists  

argued that these models are unreliable, and  their predictions should be given a lower  

weight in the IPCC assessments. They dubbed  it the “hot models” problem and I’ve found it  

both funny and concerning that the double meaning  didn’t occur to me until a friend pointed it out.

Now the reactions of climate scientists to me  saying the problem has been underreported have  

basically been two. First: Doesn’t matter what the  climate sensitivity is, that’s just distraction,  

we need to stop global warming anyway. And second:  Well, there are a lot of papers every year coming  

out with different climate sensitivities,  and one shouldn’t pick one here or there.

About the first point: Doesn’t  really matter, it’s bad either way. 

I think that climate scientists who say  this have totally lost touch with reality.  

Governments make plans for reaching net zero  based on expectation for how fast the situation  

will get worse. The climate sensitivity is  super important for those plans. If you,  

and I’m talking to you climate scientists, get  this number wrong, then all current plans will  

be grossly off. I really don’t understand how  you can just go and say it doesn’t matter. You  

might as well go and say it doesn’t matter  what climate models predict in general.

A particularly crude example comes from Zeke  Hausfather and Andrew Dessler. Hausfather was  

one of the authors of the article in Nature  magazine which coined the term “hot models”.  

In the blog post they write: “Arguments  over the Equilibrium Climate Sensitivity

are distractions. Whether it’s 3 or 5 degrees is  

a bit like whether a firing  squad has 6 rifleman or 10.”

Someone’s got to say it, so I will. That’s  a really bad comparison. Because the climate  

sensitivity does not tell you how big the  problem is, it tells you how fast it will  

become worse. Do you have to deal with  six riflemen next year, or do you have  

a century to think about how to deal with  them, that’s the question we’re looking at.

Now about the second point: there are always  many papers. Yes, but this wasn’t my point.  

The reason that Hausfather et al were going  on about this is that the problem appeared,  

not in any paper, but in some of the best climate  models in the world. Models that are so good that  

climate scientists had previously decided  to include them for the IPCC predictions.  

It was only after some models produced  values that they didn’t want to believe  

that they looked for a way to do get rid of  them. This is the problem I am highlighting.

It worries me because the same thing has happened  many times in physics. A particularly stunning  

example is the lifetime of the neutron.  The neutron is one of the constituents of  

the atomic nucleus. It’s stable so long as it’s  inside the nucleus but take it out and it decays  

in about 10 minutes. That’s interesting in and  of itself, but well this is not a video about  

nuclear physics. The thing is that physicists  have been measuring the lifetime of the neutron  

many times and updated the value. You can see the  progression of their measurement results here.

What you see is that the measurement seems be  comfortably sitting at some particular value. Then  

they suddenly make a jump. It’s not like the error  bars just gets smaller. They jump to outside the  

previous uncertainty region. Often this happens  with new measurement methods, and it means that  

physicists have systematically underestimated  the uncertainty on their measurements.

Even more amazing this didn’t  happen for only one quantity,  

it happened for dozens of them. What is going on?  Well, it’s difficult to say exactly what happened  

there but the explanation that sociologists  have come up with is confirmation bias. 

A lot of people think confirmation bias means  you only look at information that “confirms”  

your prior beliefs. But this isn’t how it works,  because you get information thrown at you whether  

you like that or not. The way that confirmation  bias works is that if a finding doesn’t agree with  

your prior believes, you think about it very  hard and try to find something wrong with it.  

Whereas when it fits, you just accept it because  it’s what you said anyway, so why think about it.

In science this shows up as follows.  If you get a measurement result that  

doesn’t fit with the previous ones, you are  much more likely to look for a mistake than  

if it would fit. And this introduces a  bias to confirm the previous finding.

Physicists have learned from their past  mistakes and now try to avoid this issue  

by deciding on a method of analysis before  they even look at the data. Then they apply  

the analysis to the data blindly, crunch the  numbers, and only then do they “unblind” the  

result and look at it. This result then  gets published without further changes.

But this is not what climate scientists have  done have they. They’ve changed their way of  

how they interpret the prediction of the  models after some of them produced results  

that didn’t fit their previous narrative. Clearly the collaborations who work on the  

models with the high climate sensitivity think  that they are the ones who got the physics right,  

so any such argument will have to weigh one  type of evidence over another. It’s a subjective  

assessment that masquerades as objective. The  bottom line is that I believe the uncertainty  

on the climate sensitivity is much larger than  the current IPCC projections make it look.

And yes, I’m not a climate scientist.  So you can try to dismiss my concerns  

by saying that I have a PhD in the  wrong field. But I have seen how even  

large scientific communities reinforce their  prior beliefs and arrive at wrong conclusions,  

like the idea that the large hadron collider  would see supersymmetric particles. And I  

don’t think that the community of climate  scientists is immune to such problems.

Humans are part of nature and if nature isn’t  doing well, we aren’t doing well either. At  

least that’s what I believe. I also believe  in the power of the people and that if we work  

together we can turn the boat around. This is  why I am so fond of my friends at Planet Wild.

Planet Wild is not your average environmental  gig. It's a family of nature enthusiasts who've  

got their hands in the dirt and their  hearts in the right place. Their big  

goal is to bring ecosystems back from the  brink of collapse with missions financed by  

community contributions. You support them, they  do it. I joined Planet Wild earlier last year,  

and I’ve been really impressed by their work.  It’s practical, it’s useful, and it’s realistic.

What I particularly like about Planet Wild is  that they respect their supporters. They don’t  

just take the money and disappear with a  “Thank you.” No, They document all their  

missions with video reports that you can  find right here on YouTube. For example,  

in their latest mission they're reviving a  once-diverse Caledonian woodland from its  

monoculture plantation state, restoring the  natural biodiversity and balance it once had  

by doing the opposite of tree planting. The  approach is surprising and kind of genius!

If you want to join a growing community that  makes a real difference, go check out Planet  

Wild through the link in the description  or by scanning the QR code. You can help  

them help nature for as little as $6 a month.  And don't worry that you get stuck with them,  

you can cancel your membership every month.  If you’re among the first 200 people signing  

up with the code SABINE, I’ll cover the first  month, so don’t hesitate, go and have a look.

Thanks for watching, see you tomorrow.