34 Comments

Even a one rifleman firing squad is pretty bad when you think about it.

And thinking about it that way would have been a good idea back in the 1990s. Sigh.

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Economists are rarely humorous but a dead clock is right twice a day, that is if you're old enough to know what an analog clock is. Economists say predictions are difficult, especially about the future. There is an overabundance of evidence that we have had a considerable over-reliance on modeling. And when combined with the maximal conservatism of scientific paper publishing language, vs using actuarial principles to convey risk analysis to the public and policy makers, the result is we are heading into rougher waters faster than we are prepared for. While I appreciate the complicated nature of this topic (modeling) I must admit that I find any discussion of whatever the F the IPCC does, says, averages, models or fingers to be a complete violation of rational analysis, given that the IPCC is a politically driven vehicle, not a science based arbiter of truth. And my sincere apologies for using the word truth in this (or any) context but I didn't want to spend too much time overthinking this absolutely inconsequential and utterly irrelevant reply. I used to think that our societies will collapse, if by climate change, due to solving it was not economically profitable enough. Then I started thinking that we will more likely succumb to the inevitable regulatory blockades without enough time to unravel the contradictions in our man made paradigm. Lately I've been thinking that it may be we've spent too much time averaging the model results in an effort to comfort ourselves. I'm voting for Massive Asteroid 2024 for President, campaign slogan: Not Soon Enough. Sorry. Sh*t got dark all a sudden. :/

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I think we agree the scientists who write the IPCC reports are not politically driven and their summaries of the science are endorsed by every scientific institution and society on the planet. In retrospect the reports may appear "optimistic" but even so they're bad enough for warnings to be issued: we must halve emissions in say 10-15 years.

As for societies collapsing... Do you watch Al Jazeera to see what Israel is doing to Gaza, with the support of America and its protection in the Security Council? (Saying it's not genocide is like the WHO's Tedros saying Covid-19 is not a pandemic at the same time we saw on television the Italian army trucking away corpses when the undertakers couldn't cope. The problem as always is the difficulty of agreeing on a definition, not what we are seeing.)

I suspect that's only the beginning of what we'll see as countries run out of water and food. I'm knocking 81 and if I live as long as my father (98) I might see my new grandson (<1) in the UK die in this manmade disaster.

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A truly horrible thought Dennis, lo siento. I think you and I probably see the same slow motion trainwreck. Where I will differ with you is with the credibility and control mechanisms of the IPCC. I personally don't know any climate scientist who thinks their process is worthy of applause or validation. Understanding how scientists think, communicate and are constrained is important to understanding why the IPCC hasn't been given the collective middle finger by the larger scientific and climate community. The good intentions of the scientists who contribute to the IPCC should not be questioned, and I am not. The framework they operate in is simply not one of their making. Hence the name: Intergovernmental Panel on Climate Change. It is there to assess the science and it does so in the least urgent and diligent way in terms of human response to this accelerated rate of system change, but in the most maximal way of abating political discomfort among participating governments. And please don't misread my ire for some hostile conspiracy theory. Rather I just think we are all flawed and everything we do is mired in compounded flaws. If you are looking for scientists to save us, you'll be quite dismayed to find that isn't what they do. They study problems. They don't solve them (any more than an engineer does science). And you can't study your way out of this. I do appreciate your articulation and point of view Dennis. And your statement about your grandson is poignant and terrifying.

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I'm not sure you understand the IPCC report process. Lead and contributing authors are often active and respected climate scientists. I believe Zeke has been both a lead author and contributing author and so has Dr. Jessica Tierney whose work Zeke highlighted in the article.

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Oh man, the list of things I don't understand is miles long.

Yes I know the scientists involved are credible and selected because of their credibility. I am taking a wider, more zoomed out view as part of the schematic overlay in my zoomed in opinion. Yes, the IPCC is an advisory board attempting to inform the participating governments via their assessment of the standard middle ground aka average of the aggregate balance of scientific peer reviewed literature. This process is therefore slow and constrained in the way a fish is constrained to water. Meaning, the entire contextual language that scientists use is different than the language you and I and 99% of humanity uses to discuss our perceived reality of what is coming. This video does a great job of explaining in very basic language, part of how or why scientists are overly conservative: https://www.youtube.com/watch?v=X-FJvzgrM00

Scientists are absolutely our guiding light and yet they and the institutions and processes they work within are deeply flawed, (just like everyone and everything humans touch, unfortunately), but in their own special way. Understanding those specific flaws and the specific effects those flaws produce is not commonly understood. Hence people think the IPCC is a truth telling service, which it isn't really, it is a scientific literature averaging service.

Look, I'm not trying to convince anyone of anything, rather I'm communicating that after 16 years of working with climate and marine scientists and their institutions and being a diligent student of the work they produce AND in rather frequent conversation with many of these brilliantly intelligent people, who are ALL deeply worried about the oncoming train wreck (even Dr. Michael Mann, who I vehemently disagree with but hope he gets proven correct), there are real flaws in the communication, modeling and analysis frameworks. All flaws have consequences. One of these consequences is that the climate risks have been severely underestimated due but not limited to an over-reliance on flawed modeling and through a communication framework that is uniquely different from how the rest of us operate.

If you ask a fish how the water is today, that fish might not understand the question.

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Where is Michael Mann wrong?

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I think he is wrong in that he believes and promotes that once CO2 levels begin to decline, temperatures will decline (10 years).

- The paleoclimate record shows no evidence of this claim, in fact, it shows the opposite with up 1,500 years of lag time in some instances between CO2 level declines and temperature declines

- He discounts the feedback loops in the system whereby if CO2 levels decline, there is no delayed response (in his view) across the system where feedback loops take longer to respond and eventually diminish in their effect.

- He ignores the heat sink of the world ocean. Due to simple physics in ocean currents and fluid dynamics, the heat energy would not be able to reach the surface in its entirety in a 10 year window. And given the mathematical near certainty that we will be adding an enormous amount of heat energy to the ocean system before we are fully decarbonized combined with the amount we have already put in, means that we will have quite a while before the heat energy is expelled from the climate system.

- He ignores or doesn't value that we simply do not know how much damage can or will be done by simply staying at 1.5 or 2.0 c above pre industrial levels. Should we find out by doing it or should we try to avoid that? I guess it partially depends on your risk tolerance and your willingness to risk your kids, your grandkids, the future of other species. And that is where I vehemently disagree: let's not risk everything just because we're all collectively dumb.

I'll add to this the inferiority of models that do not accurately account for either cloud systems or methane (among other flaws), means we primitive apes should not rest on the assurity of mathematical models where we design the configuration of inputs to said models knowing we are going to be wrong and then claim that the risks are fine (don't worry) despite evidence to the contrary.

Thus, Mann is wrong on his claim of immediacy and that claim is giving humanity a false sense of security and a false sense of security in my opinion has contributed (mightily) to inaction. I'll give Mann a high five if he actually believes there is nothing we can do about this and therefore doesn't want to ruin supper. But I don't know if that is the case. At the end of the day his claims have real consequences where people think everything is mostly fine and all we need is EV's and solar panels (which would have been impactful if we started that transition in 1990).

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"Arguments over ECS are distractions."

I couldn't agree more. If there is value I think it will be in terms of improved models and helping to quantify the challenges that we will face in terms extreme weather, ice sheet melt, and sea level rise. Even then it doesn't change the urgency of decarbonization. I'm afraid the people that already care are doing what they can and one more alarm bell won't get the attention of people that don't believe that it is serious.

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As an economist, I totally agree with your comment on economists. The profession can’t predict a great recession (2008) or a robust recovery (this past year) and has largely failed to incorporate nature into its theory or models. Of course there are a few wonderful exceptions, but for the most part…

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When humans were hunter-gatherers we would have likely survived the present warming. But now most live in a very fragile society - I could barely feed myself for a week if the shops closed and the power to the freezer went off.

For us now the uncertainty merely affects the time we have to reduce emissions to net zero, not whether or not we must. And we are already behind schedule based on what we see already.

In my inexpert opinion civilisation as we know it will not survive 3K mean global surface temperature increase, considering 90% heat is going into the oceans.

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I find the whole idea of averaging models quite strange. Surely the models should be weighted by historical accuracy: models that fail to reproduce historical behaviour should be weighted very low.

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Can someone link me or teach me a bit more about the natural cycle of temperature rising which leads to higher carbon emissions over the course of millions of years? I’m under the impression that modern climate change is due to carbon emissions elevating temps.

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I'm wondering how you gathered the data for the CarbonBrief plot "Timeline of published equilibrium climate sensitivity studies" and if you have any advice for me if I wanted to gather that same data, and combine it with ECS estimates since the article was published in 2018. Are ECS estimates stored somewhere centrally, or, as it sounds like Prof Reto Knutti did in the paper referenced, does this require going pdf by pdf through all recent ECS studies? If so, is there a good way of at least zoning in on the relevant papers?

I think this is probably a question for Zeke and I also tried to message him directly. I'm not commenting to pester lol just in case he doesn't check his substack DMs as I know I don't.

Thanks for such helpful analysis!

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Hi Max, here is the spreadsheet updating Reto's work through the end of 2018. Feel free to update it if you have the bandwidth (and I'd check with Reto to see if he might have already done this!): https://docs.google.com/spreadsheets/d/1vZ4Pq0bRY7R0Bd382ihFKdQUJjxV38aHhrIL0K6N6wg/edit#gid=0

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Wow I can't thank you enough. I will reach out to Reto in case I could really be that lucky. I'll update you here if I am :)

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I appreciated the discussion about models and their strengths and weaknesses. Question: it’s my impression (and I believe the latest IPCC report said as much) is that for the most part, the incredible climate research and modeling being done is somewhat siloed at this point (not a criticism!) and that climate scientists are just beginning to model synergies between, say, something atmospheric and something to do with glaciers. There’s also the challenge of modeling threshold effects/tipping points. Are my impressions correct? If so, would that indicate that the models are somewhat conservative, and that climate impacts may come sooner and be larger than current models predict? Thanks for any light you can shed.

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Very much appreciate the excellent and even-handed analysis, thank you.

But still, I'm worried that all these models -- which are basically roadmaps of the end of the world (with side commentary by the authors noting various off-ramps) -- are simply wrong. What if scientific modeling about such a wicked problem is similar to the dismal and wicked science of economic modeling? If so, we should all remember that the world's top economists were predicting smooth economic sailing as late as November, 2007, right before the Great Financial Crisis -- a terrible catastrophe that could easily have returned us to the tragedy of The Great Depression.

For example, what factors have been neglected or underestimated that could quickly accelerate warming (air and oceans) much faster than anyone, or any model, anticipated? What about ocean temperatures climbing much more rapidly in the past year than any model anticipated? Is that anomaly consistent with modeling projections? Are there others, such as methyl hydrates? We were all surprised by shipping aerosols last year (something I worked on 20 years ago), so what other surprises lay in store?

It would be great to have a model to incorporate the historical climate surprises that have already happened, to project out other future surprises that will undoubtedly come. Hopefully, they are now all accounted for :) But unlikely.

There are the things that keep me awake at night!

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The failures in the models that are known are:

- cloud systems and the complex who what when where why how of cloud patterns and their effects.

- methane from permafrost and seafloor (methane clathrates) are poorly modeled if modeled at all (some models do not include this because of uncertainty and that too is a wicked problem where it is extremely difficult to model things that we just don't know enough about).

- Complex ocean dynamics that range from sea surface temperatures and effects to biogeochemical conditions that are changing to the effects of biologic declines and/or changes in their locations which may have impacts beyond our current understanding and therefore modeling

- Carbon sources and carbon sinks are changing in real time and this is not exactly easy to fully track accurately, therefore, again, the models lag behind.

- There are other knowns that are problematic, but you get the point. Now onto the big problem. . . . . !

- The unknowns. How do we know what it is that we don't know? Yeah. That is a reality we are living with. There is no way to know what it is we don't know until we realize whatever that thing might be and then clumsily figure it out over time.

Forkenstein.

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Great summary of our concerns, both known and as of yet, unknown. This is why we should all be very very nervous, and why Michael Mann's comments may actually be quite harmful. He continues to highlight the fact that we don't yet see any signs of acceleration. But that's like a car driving 100mph towards a cliff, while the driver says, "So far, so good!"

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Always appreciate your articles. Thanks for writing them.

I get that all the things she mentioned are going to happen to one degree or another, however she mentioned a few billion people dying and society essentially ceasing to function. I know things are going to be immensely challenging, but that just seems overblown for attention and views.

I read articles telling the public your kids aren't going to die from climate change, and then Sabine summarizes rcp8.5 on steroids and it gets shared everywhere on social media.

Both can't be right.

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We don't really know how bad climate change will be. But I think Sabine's assessment of billions dying is more likely than loss of a few percent of GDP.

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Yikes. I too agree that Bjorn's interpretation of the economic models are idiotic.

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Just wondering: is there a word missing between "very" and "climate" in the lede of your article?

"Despite a hot 2023 and the recent Hansen et al paper, there is still reason to doubt very climate sensitivity models"

(Please feel free to delete my comment once you noticed it.)

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Fixed!

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Feb 6, 2024
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Don’t put too much weight on a single study, particularly one from a single location. Let’s see if this is replicated/confirmed.

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Feb 10, 2024
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Scientists have done exactly that question with runs that isolate different forcing agents — e.g., runs with only CO2, and only solar, and only methane, etc. So we can estimate the impact of individual forcing agents.

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