Aug 11, 2023Liked by Tomas Pueyo

Presenting only the extinction rates underestimates the severity of the global defaunation. Many animals are not actually extinct yet, but many of their populations disappeared and shrunk so much that they do not fulfill their roles in ecosystems (ecologically extinct) or have so low population sizes that they cannot be exploited by humans anymore. (https://www.science.org/doi/10.1126/sciadv.1400253)

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Super interesting, thanks for sharing!

I just read the abstract and eyed the paper.

I think your comment raises a good point. What is the point of biodiversity?

Is it preserving the current variation of the genetic codes as results of millions of years of evolution, because that's valuable in and of itself? Because this diversity could be valuable to humans? Or is the amount of different animal individuals valuable for some other reason?

Is it valuable for ecological stability? Like the wolves of Yellowstone? How do we quantify that?

I am not sure I've ever read a cogent analysis of this. I would love to.

Side note: The paper you link makes a huge logic jump, from "extinction rates are much higher than background now" to "we're entering the 6th great extinction". I agree with the former, but from what I know today, not with the latter, and the paper doesn't support it.

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Aug 11, 2023Liked by Tomas Pueyo

It's not ok to present Arizona deaths from extreme heat without adjusting for crazy population growth over those same years and the age of all the snowbirds.

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Also, great piece at the Climate Brink. See section on temp-related deaths:


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I also spent my first 28 years in the upper midwest (Chicago and Madison), and I can assure you that extreme cold is far more dangerous and han extreme heat. You really have to look experience it to fully understand it.

Now, admittedly it's not as cold up there as when I was growing up there in 50s, 60s, 70s, but it's still both damp and cold, and windy, the dampness and wind will cut right through and do you in quickly if you don't get indoors with heat. That's true day or night.

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Sep 3, 2023·edited Sep 3, 2023

No! The population growth over 25 years (since late 90s) is maybe 50%. The increase in heat deaths rose 10-fold! From about 25 in late 90s to about 250 in 2022, as your chart showed! And I'll bet you dollars to donuts that 2023 will exceed 2002 extreme heat deaths. Advice: don't take that bet if you think 2023 will be lower than 2022.

This is coming from someone who actually lived in Tucson for 20 years, from 1997 to 2018.

Remember also that few Arizonans die of extreme cold. In fact, there IS no extreme cold in the region with 90% of the population. That's another fact, Mr Les.

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Aug 11, 2023Liked by Tomas Pueyo

The sulphur pollution debacle is fascinating, it would be interesting to know what percentage of climate scientists were warning that removing it from the fuel would have this dramatic side effect. Hopefully they all were, I don’t remember reading about it anywhere though.

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Most were aware of the effect of sulphur pollution cooling, and had the reduction of that cooling as pollution decreased baked into the models https://www.economist.com/business/2018/10/27/sulphur-emissions-rules-for-shipping-will-worsen-global-warming

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I didn’t know. Thanks!

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Me neither

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Aug 11, 2023Liked by Tomas Pueyo

Interesting analysis, as always. As a biologist I am not complacent that "only" 50% of species face extinction! That is catastrophic for biodiversity. Unlike the earlier mass extinctions, of course, this one is caused by human activity. It is an odd form of hubris to think that we are entitled to eliminate half of the planet's species for the convenience of using fossil fuels created by the decompsition of their ancestors' bodies. Other species will adapt and diversify, but the loss of half of extent species will have impacts that we don't and can't yet understand.

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You are right! I don’t mean to belittle it. I mean to right-size the impact. (Which, btw, will be substantially lower than 50%, but probably much higher than 1%)

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I shouldn't worry. Even if it does keep getting warmer, there's no possible way anyone could put a figure of how many species will die out. Will the amount of water in the world be reduced? Presumably not. In which case, we're talking about cool and humid places becoming hot and humid. So more like a jungle, teeming with life. But it's much more likely to be nonsense, anyway. You people want to believe in global disaster, and you ought to be asking why.

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Aug 11, 2023Liked by Tomas Pueyo

I have been careful reader of yours since you began to publish and a grateful one, but the conclusions of this post seem unsupported by evidence. 9 billion ppl plus or minus depend on the regular course of seasonal agriculture, farm raised protein sources, and oceans for calories necessary to survive. The rapidity of extreme, man-made climate change is breathtaking. Crop failures in mid latitudes have already occurred. In the southern hemisphere, this winter high temperature events are unprecedented. The oceans are changing silently and rapidly. Scientists point to evidence we are in the early stages of the 6th Great Extinction. There is a great economic shock within sight: what evidence can you point to that human ingenuity can vault 9 billion over dire consequences and that species adaptation can change quickly enough to surmount a climate unknown at any point in the evolution of civilization?

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Aug 11, 2023Liked by Tomas Pueyo

I have also been a careful reader, and it is your conclusions that are overblown. Look at this chart from our world in data and you can see crop yields are not declining but growing much faster than population.


There are always areas of drought and flooding causing crop failures, but not enough to cause reduced production (Russias invasion of Ukraine is probably more harmful). You mention reduction in mid latitudes but not increases in high latitudes.

As the article states, warmer winters means fewer cold deaths easily offsetting the rise in heat deaths.

The extinction question was also addressed in the article and is nothing like the previous 5.

The biggest economic shock of climate change appears to be the huge sums being spent on trying to address it, when we could instead paint all our rooftops, parking lots and roadways with the super white paint and achieve the same results (again stated in the article for careful readers) for trillions of dollars less than all the solar, wind, biomass and other inefficient technologies.

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Buzen, I think your last point is the more important one. This is a problem we know how to solve. Why aren't we? And more importantly, why are those who claim to worry about the problem not clamoring for these solutions?

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Thank you Alan for disagreeing. This is how we get better together.

I am trying to make a nuanced take, and sometimes it's hard with a heated debate because people react much more to what they disagree with than what they agree with. Which is the origin of the famous sentence "If I make both sides unhappy, I will have done my job."

I am not saying that climate change is good or not a big deal. It *is* a big deal and we need to fight it. I have proposed several solutions!

What I'm saying is that the persistence of humanity or the Earth and its broad diversity are not at risk—which is not something I knew before starting the series, and I'm pretty sure many people are in the same boat.

The risks you mention are indeed possible. I haven't looked into the crops yet for example, nor into the economic consequences of climate change. I might. Now responding point per point on the specific examples you quote:

1. As Buzen notes, yields are still growing. Will they keep growing at this pace? I don't know. But as a rule of thumb, technology improves much faster than the climate worsens. I wouldn't be surprised if we were able to figure out ways to keep growing yields. Seafarming and indoor farming are two obvious ways, especially combined with more, better sources of energy (solar and nuclear).

2. As I discuss, the evidence I have seen so far does not point to a 6th mass extinction at the level of the previous 5. That doesn't mean the current one is OK. It's just not going to be at the same level, and probably not at the same order of magnitude.

3. Dumb technicality: We're at 8B ppl. This does not undermine any of your points.

4. As I've mentioned in the past, it doesn't look like oceans will rise high enough this century to threaten exposed and populated places like Bangladesh.

This does not mean you're wrong. You might be very right, and I will look into it. I just want to point out that your comment does not negate anything I've said I believe. If it does, please point it out. I would love to hear that!

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I beg to differ while also finding both the article and your stance to be conservative and reductive in its analytical approach while suffering from linear reasoning.

Given that modern agricultural processes depend on fossil fuels at every stage - from cultivation to transport - it is imprudent to be overly optimistic about our current predicament. For example, in a study published in “Energy Policy,” it was estimated that the modern food system consumes roughly ten calories of fossil fuel energy for every calorie of food energy produced. This fact alone should caution against a conservative outlook.

Moreover, the phenomenon of warmer winters, leading to species migration, is a significant concern. This is not merely a shift in populations but spells a systemic biospherical alteration that current models struggle to predict. Studies on bird and mammal migrations have shown shifts in ranges in response to climate change, reflecting this unpredictable nature. Labeling such a complex process as a mere inconvenience is both anthropocentric and arguably narcissistic.

Additionally, the analysis overlooks the potential consequences for poor countries where conditions are approaching wet-bulb temperatures, which are lethal to humans. Research in “Nature Climate Change” highlights regions that may become uninhabitable due to extreme heat and humidity, exacerbating inequalities.

The reduction in snow accumulation at the tops of mountains due to warmer winters is another overlooked factor. This snow, when melted, often provides crucial water supplies for human populations. For example, the Hindu Kush Himalayan region serves as a critical water tower for more than a billion people, and reduced snowfall has serious implications for water security.

Taken together, these factors underscore a profound dependence on fossil fuels that characterizes our civilization. Assertions that this dependence will vanish without significant societal upheaval are unsupported by the available evidence. Far from being a peripheral concern, this dependence is central to our way of life, and its ramifications are likely to be felt across the biosphere and human society alike until modern civilization undergoes substantial transformation.

P.S tipping points alone can lead to exponential changes that no animal can adopt to.

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Thanks Alexey! Fantastic debate. Reactions:

1. You mention my stance is conservative. What do you mean? I'm trying to be nuanced here. My stance is: This is really bad, but it's not world-ending bad. Do you disagree? Specificity here would help.

2. Indeed our dependency on fossil fuels is bad. I wish we didn't have it. But:

i. We're moving away from them pretty fast right now (solar! wind! Exponential growths!)

ii. We know how to move away even faster (nuclear!)

iii. We know how to revert its climate change impact in the short term while we transition

iv. Outside of that, the only issue might be that we're running out of them, but we're not.

3. I agree that species migrations is an important factor. My understanding is that its impact falls into the "species extinction risk" that I mention, which I quantify as "probably higher than 1% and much lower than 50%" from what I know today. this is bad! But not Earth-ending. Why would claiming this be narcissistic? I can agree that it's anthropocentric though. On this, what would be the best way to quantify the value of this biodiversity?

4. Wet bulb is a serious issue. So far, this is accounted for in the "hot vs cold deaths" argument. I think you might be suggesting that there might be a non-linearity there. I agree. But if that's true, there might be an even stronger non-linearity: human adaptation. Wet bulb has a known solution: AC. It's a matter of throwing money (and tech) at the problem. Based on the past track record of humanity, I believe we will AC the world faster than wet bulb temperatures will become a problem?

5. The water security is indeed a serious problem. This might cause many downstream problems.

6. I did not assert "that this dependence will vanish without significant societal upheaval"! AFAIK. Please point out to me if I did. Overall, I think this is the most salient part of your comment. I fail to understand specifically what it is that I said that you disagree with.

7. Tipping points are by far the single most important wild card here. As I've mentioned before, the entire analysis assumes no massive tipping points. Today, this is supported by evidence AFAIK. AMOC is the one that seems most likely at this point, and its effects would not be great indeed.

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1. The stance, owing to its nuanced nature, overlooks the multifaceted nature of the system. Models that were forecasted, with ever-increasing accuracy through artificial intelligence and supercomputing, to predict the climate phenomena we are witnessing today for later in the century, are now too generalized and outdated. The subtlety that your argument underscores also neglects the interconnectedness of multiple chains within the biospheric system. While these may not portend a world-ending scenario, they certainly pose an extreme risk to modern civilization, predicated on infinite growth and extractive practices, and this alone should serve as a substantial warning against excessive optimism.

2. Wishing without action is akin to a lake without water. To respond to the subclauses,

i. Who does ‘we’ refer to in the premise’s context? If the allusion is to the global economy, then this constitutes hollow propaganda. Fossil fuel demand has risen to an all-time high, once again. Consider the global data chart on energy consumption and the sources from which that energy is derived; humanity is nowhere near relinquishing its tenacious grip. Such an assertion verges on delusion and is founded on confirmation bias.

ii. Building and activating a nuclear plant requires a decade or more. Approximate calculations indicate that humanity would need to construct around 400 nuclear plants each month for the next decade to supplant fossil fuel energy extraction, not accounting for the projected increase in energy demand.

iii. Tomas, would you be kind enough to elucidate what you mean by “We know how to revert its climate change impact in the short term while we transition”?

iv. Regarding “running out of them,” could you please specify what the statement aims to convey, and more explicitly, to whom “them” refers?

3. My quantification approach is both holistic and dialectical-materialistic in nature. As it stands today, the distribution of living biomass offers a stark insight into what humanity confronts. A mere 4% of living biomass is classified as wild, with the remainder being domesticated animals and humans. The exponential growth in population and corresponding urbanization, whose fundamental premise was human-centered planning, signifies a paradox overlooked by many critics. Catton’s “Overshoot: The Ecological Basis of Revolutionary Change” already articulated the complexities of overpopulation and urban sprawl. Your hypothesis seems to suffer from a human-centric perspective, neglecting the necessity of a comprehensive approach to understanding.

4. This clause resonates strongly with my objection to your conservative stance that overlooks peripheral issues. Air conditioning, to state it succinctly, is but a short-term remedy. Present-day power grid infrastructure lacks the capability to meet high-demand periods, a deficiency glaringly evident during extreme weather events across extensive geographical expanses. In North America, the absence of meaningful investment in grid resilience even during times of stress is apparent. Your premise appears flawed, predicated on an unduly optimistic projection of future technological solutions. The uncritical embrace of techno-solutions gives me great pause, especially when considering the naivete that has led some to believe in unending growth. While not dismissing the potential of specific technologies, I acknowledge the very real apprehensions surrounding their implementation within systems controlled by autocrats and oligarchs, whose actions often seem driven by a desire to maintain the status quo.

5. I take exception to the use of the term “might.” This word, in my view, trivializes the challenges that humanity is both facing now and poised to encounter, and casts a shadow of doubt over meticulously researched findings on water security. I emphatically disagree with this characterization, Tomas.

6. My apologies for any confusion on my part. The assertion was crafted in a manner similar to the argument you have presented.

7. The Atlantic Meridional Overturning Circulation (AMOC) may reach a tipping point between 2025 and 2050, with the median forecast at 2037, subject to a margin of error. The tipping point for Greenland’s ice sheet may have already occurred; the Amazon is now a net emitter of CO2. These represent critical junctures in our climate system; it behooves us not to overlook corresponding tipping points within social and other animal systems.

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Aug 13, 2023Liked by Tomas Pueyo

People project their own fear of mortality on the demise of the earth.

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In response to the claim made in the article, I find it to be characterized by a refurbished, reductive analysis that fails to consider critical tipping points or accurately account for the complexity of the biosphere. This oversight undermines the validity of the conclusions reached.

Furthermore, the article’s perspective seems steeped in an anthropocentric view, focusing solely on human interests and neglecting the broader ecological context. This stance stands in stark contrast to a body of peer-reviewed literature that recognizes the interconnectedness of human and environmental systems.

For instance, recent research in journals such as “Science” and “Nature” emphasizes the necessity of considering tipping points like ice melt and forest dieback, as they have cascading effects on global ecosystems. Ignoring these factors results in an overly simplistic and flawed understanding of our relationship with the environment.

The dismissal of such complex interactions constitutes a fundamental weakness in the article, leading it to present premises that are not only at odds with well-established scientific findings but also risk perpetuating misunderstandings about the intricate and delicate balance that sustains our planet.

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Thanks Alexey. You're right! I've mentioned in the past that I specifically don't take into account tipping points yet—mainly because no tipping point seems likely today outside of the AMOC's collapse, based on what I read (by likely I mean "of having a high likelihood to impact us in the short to medium term"). And even then, it's not clear the AMOC collapse will happen. But I might be wrong, and might look into this.

As mentioned in my other reply, I am curious about the quantification of biodiversity value!

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Aug 11, 2023Liked by Tomas Pueyo

What do you thing about Hunga Tonga volcano erruption in January 2022?


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I just read that a couple of papers have quantified its impact as quite low? It might have contributed at warming up the world, but I believe the order of magnitude is something like 0.01ºC

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Aug 14, 2023Liked by Tomas Pueyo

Very interesting analysis - but condensed of course. I suggest that comparing deaths from cold to deaths from heat misses vast amounts of nuance. For want of my time I quote a science journalist, Gaia Vince, in an article in 2019 "From 2030, more than half the population will live in the tropics, an area that makes up a third of the planet and already struggles with climate impacts. Yet by 2100, most of the low and mid latitudes will be uninhabitable because of heat stress or drought; despite stronger precipitation, the hotter soils will lead to faster evaporation and most populations will struggle for fresh water. We will have to live on a smaller land surface with a larger population.

Indeed, the consequences of a 4C warmer world are so terrifying that most scientists would rather not contemplate them, let alone work out a survival strategy." (https://www.theguardian.com/environment/2019/may/18/climate-crisis-heat-is-on-global-heating-four-degrees-2100-change-way-we-live)

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1. The 4ºC warmer world appears unlikely at this point

2. Water availability is solved with cheap desalination, which requires cheap energy, which we'll get with solar PV, maybe wind, and, if we just accept it, nuclear.

3. I have not seen yet models that suggest the scenario she mentions. It sounds like a 4ºC scenario, which is unlikely?

4. I somewhat discount the emotional load of global warming comments made by people called Gaia.

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Hi, about crops: here is an interesting article in today’s Guardian: https://www.theguardian.com/environment/2023/aug/12/global-heating-likely-to-hit-world-food-supply-faster-than-expected-says-united-nations-desertification-expert?CMP=Share_iOSApp_Other

Food shortage will lead to huge armed conflicts and more migration. That will be a bigger challenge than the higher temperatures by themselves. (I think)

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Thanks for the link!

Here's a heuristic that I've developed: When I see a claim about climate change, I immediately ask 3 things:

1. What papers are you referring to? Because there's too many ppl reacting to flimsy concepts rather than science they've read

2. How does that fit with everything else I know? Because if there are glaring inconsistencies, the argument falls apart

3. Who is the person saying it? Because I'm finding 2 types of personas: scientists who have deep but narrow expertise, and broad communicators that don't have any depth. There are some rare experts who have both breadth and depth.

In this case, the article is not very strong:

1. I don't see papers, it looks like the person is mostly sharing opinions?

2. Agricultural yields have consistently improved over time. In the race of technology vs climate, technology is winning handily. It will likely continue.

3. This does not look like a deep and narrow expert, and it certainly doesn't look like a depth&breadth kind of person

I am open, however, to get this appraisal wrong, since I need to optimize my time and can't dive into every single one of them!

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I'm curious what you think of Kevin Drum's argument that it's unlikely the changes in sulphur pollution had a significant impact, just based on calculation of solar energy involved: https://jabberwocking.com/update-sulphur-limits-still-arent-responsible-for-the-unprecedented-heat-this-year/

"On average, solar radiation amounts to about 1000 watts per square meter. According to a study quoted in the article, this compares to an increase of 0.1 w/m² due to the sulphur limits. That's not a lot.

The 1991 Pinatubo volcano, for example, reduced solar radiation by about 4 w/m², which led to a global temperature drop of 0.5°C. This suggests that a change of 0.1 w/m² would produce a global increase of about 0.012°C, a very small amount."

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Thanks for the link! Just read it, as well as the Science article.

I'm not sure these things are at odds?

I don't think anybody is arguing that the sulfur thing is the single biggest culprit of NA heating. There's this year's low Saharan sand carried by the wind, for example. El Niño is a bigger contributor, and outside of that, this year's heatwave is within the expected range.

The sulfur thing is relevant in a different way: "We've been geoengineering climate. Maybe we should just continue? Maybe at a bigger scale?"

This is what scientists are trying to figure out right now

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One more reply . . .

I do appreciate your response to my comments, and I hope it isn't taking advantage of your hospitality to say that I've been thinking about an aspect of the original post that I find irritating and I want to try to explain.

First, a caveat. I'm a new reader of yours (following the recommendation of Elle Griffin, and some of my complaints may well have been addressed in previous post. Second, I'm sure you've been studying more about climate change than I have, so I want to primarily address the framing of the issues; since on any particular point your likely to be better informed than I am.

Every reader is going to want different things. For me, having followed news about climate change for most of my adult life and seen a number of stories that tend to fall into three different categories (1) the immediate impacts of climate change are becoming visible quite quickly, (2) there's still a great deal of uncertainty but the worst case scenarios that had been envisioned now seem less likely, and (3) the more we study the complexity of various ecosystems the more difficult it is to predict (or mitigate) any individual harm in isolation (as an example, this fascinating article about the difficult of relocating plants Northward to assist their adaptation to climate change: https://www.motherjones.com/environment/2021/10/trees-forests-assisted-migration-fire-climate-joshua-redwoods-sequoia/ )

So my questions reading a new story about Climate Change are (1) does this change my perspective or fit within my prior understanding, (2) how much uncertainty should I have about the story (and the picture of global ecology that it presents), (3) how large is the effect being described?

I have a difficult time answering those questions reading your piece. Overall I agree with your general framing (certainly your points 1,2,3, & 5; I have some doubt about point 4). But, for example, when you say that we are unlikely to see 75% of species go extinct, but that it is nevertheless important to do whatever we can to preserve biodiversity, I don't really know how to apply that information. How bad would it be if 20% of all existing species were to go extinct in the next 40 years (I assume extremely bad, but I don't have much of a scale to work with)? How likely is that?

Second, in one of your covid pieces you talk about the importance of calibrating statements. I'd like to see some of that engagement with uncertainty in this discussion of climate change.

I realize that you're trying to engage an audience and too much attention to uncertainty can lead to boring, overly-qualified writing but . . . . I'd be curious if you could assign a percentage confidence to statements like:

"In other words, we should start burning sulfur again."


"Apparently, coating 1-2% of the Earth in this paint would reflect enough sunlight to stop global warming. "


"on balance, fewer humans are likely to die from climate in the future than do now. "

or (from your article on farming the ocean)

"the upside [of iron fertilization] is known,"

On that last one, for example, it's clear that you've done a lot of reading on iron fertilization. It seems clear that there is the _potential_ for great upside, but are we really certain about that? Does reading an article like this affect your calibration on that upside at all: https://news.mongabay.com/2020/03/climate-fix-fertilizing-oceans-with-iron-unlikely-to-sequester-more-carbon/

"According to Lauderdale, the impacts of iron fertilization in a dynamic ocean ecosystem are much less straightforward than those Martin saw in his bottles. “Over the last 20 or 30 years, we’ve gotten a much better idea of how interconnected the ocean is,” he said. For instance, the excess nutrients that are not consumed by phytoplankton in the Southern Ocean “get folded into the ocean circulation, and they outcrop in more dusty regions where there’s lots of iron,” he said; the process provides around 75% of the nutrients that feed phytoplankton growth in the northern oceans.

It’s not a one-way relationship either, the researchers found by simulating the mineral concentrations and circulation patterns found in different parts of the ocean to investigate the interplay of microbes, iron and other nutrients. Phytoplankton have evolved the ability to produce organic molecules called ligands, which make iron more bioavailable. The researchers found that ligands secreted by phytoplankton in the North Atlantic carry iron as they ride currents back into the Southern Ocean to feed the phytoplankton there. “The microbes have this ability to tune the marine chemistry for their own purposes,” Lauderdale said, “and so they’ve engineered this system to be optimal for themselves."

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Aug 22, 2023·edited Aug 22, 2023Author

Respectful dissent is my favorite, as I get to learn. It's the very point of this. So thank you!

Your comment is fair. To react, I need to explain what I'm trying to do with Uncharted Territories (UT).

I believe it's very important to have an deep and accurate understanding of a very broad set of topics to be able to predict where the world is going. For example, if you study fertility crisis you might be happy because you fear about the environment, or you might be worried about the drop in innovation and thus the economy. Or you might realize it doesn't matter because there will be an AI singularity. So to understand fertility well, you need to know about environment, innovation, economy, and AI.

Naturally, it's hard to go both broad and deep, so I need to be careful in both directions: What topics should I dive into? How deep should I go?

I also try to accelerate the process as much as possible, and a key way to do that is studying in public. The last 5 climate articles are this: Me looking into the current status of climate, sharing with everybody, and then giving me feedback on what's right or wrong. This helps me figure out next steps.

For example, as you mention, what's very clear is that a next step would be to look into non-linearities (aka tipping points). Another is more geoengineering. Planetary boundaries. How to apply the precautionary principle. And so on. So over time I'll probably dive into these.

This is why I'm much broader in my statements about climate change. I've been looking into it for 4 months, whereas I've been looking into COVID for 3 years, and my accuracy record on it is quite high, which means I'm better calibrated there. If / when I get to the same level of calibration with climate change, I will quantify my predictions.

Does that make sense?

A good example of this process is iron fertilization. Having read about a dozen papers on it, I'm more confident on my predictions there than in other parts of climate change. So I can have immediate reactions to what you say:

- Iron usually is not a pollutant in the ocean, as it falls relatively quickly in the worst case scenario, and the ocean depths have been a de facto geologic dump for eons.

- Iron is already everywhere. It's in fact one of the most common elements on Earth. So it's not really a pollutant

- Nearly every single time iron fertilization has been tried, there's been algal blooms, suggesting there is a need for it

- Iron bioavailability is not usually a pbm. The pbm is nitrogen bioavailability, and iron is the limiting factor to make nitrogen bioavailable. So it's not like iron is there but ocean algae can't metabolize it. When it's there, they do. It's just not usually there, so algae can't take it, and without it, the few that can break down the N2 triple bond to make nitrogen bioavailable, can't do that.

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As I'm reading your link now, a few more reactions:

1. Ocean circulation takes hundreds or thousands of years. By then, we will have a much better understanding of the world and a better ability to affect it. So we need to solve our problems in the next few decades, not centuries. Depleting north atlantic iron through south atlantic fertilization should not be a concern.

2. The paper linked by the article is confusing, I think because it's not phrased properly. The very 1st sentence is "Marine microbe growth is limited by iron over about half of the global ocean surface" so it's absolutely impossible that the conclusion is "therefore there's enough iron available". What I *think* it says is "iron would be even more scarce without the ligands, making it a total and critical limiting factor, but thanks to the ligands it's only limiting growth in about 50% of ocean surface". If this is true, it's still limiting bacterial growth in 50% of oceans! Also, this is for microbes, but does that include all bacteria? Cyanobacteria? Algae? Seaweed? Phytoplankton?

3. My current thinking about the precautionary principle is we should never stop doing something because we can imagine that maybe something bad happens. With that logic we wouldn't do anything. If we know something bad happens, we stop. If we fear, we try and then assess the issues that emerge. The faster we try, the more we learn and adjust.

Note that the article doesn't mention a single thing we know would jeopardize this idea. Only fears. And opinions: “I THINK we should tackle the source of the problem — reducing our carbon emissions — rather than trying to come up with band-aids”. Well guess what, we're not cutting emissions fast enough, and this doesn't seem like just a band-aid, so maybe we shouldn't close doors that make us uncomfortable just because they're alien.

This type of comment really gets my nerves: "“We shouldn’t do it, unless there are concomitant major reductions in emissions,” he said. “We shouldn’t do it until we know significantly more about how effective it will be. We should only do it if the alternative is major ecosystem/human civilization collapse.”

Well we don't reduce emissions fast enough, if we wait to know for sure it will be too late, and we need to do it now, not when civilization collapses.

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Thank you for your thoughtful replies. I don't know that anyone is claiming that the reduction in sulfur is the biggest culprit but, if Drum is correct that it is, essentially negligible, then I think the coverage has been somewhat overstated.

Yes, it is interesting to figure out what would be involved in practical geoengineering. This was a good interview: https://www.volts.wtf/p/how-to-think-about-solar-radiation#details

"So, also those two routes. I think one of the things that struck me about coming into the climate space was it wasn't very well-equipped to think in terms of portfolios. So if you look at the risk profile, it's sort of like we're having these debates about should it be wind and solar, or nuclear? Should it be emissions reductions or these things? But if you look at the risk and uncertainty involved, there's a lot of uncertainty involved in all the different ways of responding to climate change. And there's a huge amount of risk, potentially existential risk.

And so from a portfolio perspective, methane reduction is one of my absolute favorites. And there are some great things happening in that field. Adaptation is a harder problem, and it was made harder because people didn't want it in the portfolio 20 years ago. And they didn't want people to think it was adoptable. So they didn't want people looking at it. Well, it turns out when you look at it, you find out it's not easily adoptable, really. You can see, like, look at Pakistan. These big extreme events happen. They're pretty overwhelming. And even in the US, we're arguably one of the best equipped places in the world to manage these things, and Austin, Texas, had a third of the city with no power."


"[W]e didn't arrive at this conclusion ourselves. We took what the National Academy of Sciences and the Royal Society in the United Kingdom said. They'd done a couple of assessments where they gathered scientific experts together and asked the same question and if you wanted to reduce warming in the climate system quickly, what are the best candidates for research? And so they landed on [solar radiation management] because there's a lot of precedent for this effect in the atmosphere."

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I should also mention that I found this article (about the methodology of calculating deaths due to heat or cold) useful: https://www.theclimatebrink.com/p/unraveling-the-debate-does-heat-or

"The conclusion that 'cold kills more' emerges from assigning any temperature-related deaths occurring below the MMT to be 'cold-related deaths'. This would include, for example, those at 17C (63F), a temperature that almost no one would consider to be extreme, or even 'cold'.

The plot above also shows a histogram of the daily average temperature of London over the last few decades. As you can see, the temperature rarely reaches above the MMT of 19C. Thus, for London, whose temperature is nearly always below the MMT, the majority of temperature-related mortality is 'cold-related'.

If you add up all cities around the world, this result holds up and we find that, in today’s climate, worldwide cold-related mortality exceeds heat-related mortality."

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I love the Climate Brink. I hadn't seen this article. Thanks! Sounds like its conclusions match what I've said so far. Looking forward to the next 2 installments!

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Aug 11, 2023Liked by Tomas Pueyo

Wait, but most cold-related mortality is supposed to occur in warm countries and vice versa. A bit counterintuitive but believable. just imagine how someone in a hut built for really hot weather would fare when the temperature suddenly drops below 16C at night (as it sometimes does). His house is deliberately very windy and he has no thick blankets to cover himself.

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Yes a seemingly counter-intuitive conclusion and there are two possibilities. The first is what you suggest, that we are accurately measuring something which is surprising at first glace (but can be explained). The second possibility is that the measure is counter-intuitive, and that the results are surprising, because it isn't actually measuring what we'd expect.

The linked post has mostly convinced me that the second explanation is more correct that the first. The point it makes is that "cold-related mortality" is purely a correlation, it isn't directly referencing "mortality _caused_ by cold in any way." The second question is whether that correlation behaves as we'd expect. I'm less clear on that, but consider this from the linked article:

"NOAA states that extreme heat is the biggest weather killer today, a result at odds with the results described above. The reason for this is that NOAA only counts deaths where the cause of death is determined to be due to heat/cold. In contrast, the Gaspirrini method is a statistical approach that regresses “excess deaths” against temperature. Hence, these are very different methodologies."

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I read the same but wasn't convinced by the NOAA approach. I look forward to the next installments before looking into the NOAA details myself

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Yes, I don't think that the NOAA approach is necessarily better, but it demonstrates that the the different methodologies are answering different questions.

I didn't read the previous paywalled post, but I really liked the Climate Brink article and felt like it did explain what those estimates of heat and cold deaths actually measure.

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Hmm, excess deaths are definitely more numerous in northern countries during winter, right? And that's mostly because some viral diseases like it cold, and that's what kills our elderly in the winter. Do flu deaths count as cold-related?

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Looking up the paper this is the one referenced by The Climate Brink: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)62114-0/fulltext here's a later article using a similar methodology: https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(21)00081-4/fulltext

The Climate Brink piece is very helpful, without that guide I'm not sure the methodology would have made sense to me. But, yes, I read the calculation as correlating deaths (from any cause) to temperature. So if people drive more in the summer and have more deaths in automobile accidents that would count as a heat-related death. If they stay indoors in the winter and are more likely to get the flu, that would be a cold-related death.

I understand why they do that; they have to make decisions about prioritizing detail vs building a single metric to summarize a large data set, and they've chosen the second. But it doesn't match the intuitive understanding of heat- or cold-related death.

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Aug 11, 2023Liked by Tomas Pueyo

A superb and well written article with excellent supporting graphics and videos.

Thank you for the research and compilation of the data and for your insights.

Cheers from Montreal.

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Climate Realism…..

We now have escalating discord on this important subject of climate change across both experts and policy makers.

Also, we are in the grip of massive disinformation campaigns on this and many other topics that are affecting our future, and it is everyone’s responsibility to review these topics in a broad manner and from many angles and balance and value all facts and positions to gain both clarity and truth.

We need Climate Realism.

We don’t need panic alarmism or climate skepticism or attacks on our existing energy providers …. We need a realistic Climate Change Policy.

We have always had climate change and we are emerging from a cyclical ice age and are in a warming trend, but we as humans continue to be a small bit-player in this change.

We have significant Climate Change Fear Mongering from many institutional level sources that should act far more responsibly.

Climate change is NOT an emergency, and ALL the action should be on local adaption NOT global mitigation such as NetZero.

The two reasons for this approach: -

1/ Science is still very unclear that CO2 is a significant accelerator to global temperature increase with significant science studies that we have included in this report leaning firmly toward a view that we do not have a climate emergency.

2/ Building any human prosperity without CO2 generation is unthinkable and impractical. Many nations will have no option but to use fossil fuels for decades to come, and its use will continue to increase across the globe, and this approach will be essential to support any climate adaption anywhere.

I highly recommend you study these links and the sub-links, and the data contained within them.

Fact Links…..

More on climate reality…


More on the disinformation threat ….


More on Climate Change Fear Mongering


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"Fewer Humans Will Die".

You cannot possibly know that.

As for "I believe . . . ", try writing to what you know, not what you believe, T.P.

As I do . . . https://les7eb.substack.com The Decline of The West.

And as it goes down, there will be more wars and more humans will die, until The West collapses completely.

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Surely everywhere will collapse, and everyone will die. It's global, isn't it?

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We need to rewrite the Nations Sustainability Goals.. they are far too much focused on CO2 mitigation.

We must do everything we can to fight the NetZero movement and those pushing this agenda. It’s a matter of common sense as everyone you care about will be much better off in a world where net-zero has been defeated.

The Climate Crisis is fabricated by the dubious agenda of the UN and other global actors wanting to control via a world order. But this crisis is now being declared a hoax by many climate scientists (Almost 2000 of them) that are now organizing into coalitions, signing declarations and publishing articles and books that are pushing back on NetZero.

We do need some adaption from a naturally warming planet that will be far more successful and affordable than the failed, unnecessary, and unrealistic mitigation efforts of CO2 and the suppression of the life supporting power of fossil fuels.

Here is the latest published report and action plan on what is now being called Climate Realism.


If you are a climate alarmist…… its time to reset on the facts.

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Excellent comment. My comment was made entirely sarcastically, as this whole thing appalls me. And thanks for the link. All sane information is valuable

It was obvious to me that the authorities were lying when they changed to dark red weather maps. And when the reporter in Florida was almost knocked over by the wind in a storm of unprecedented violence, while in the background a man strolls over the road to his car.

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One would think so.

The billionaire class think they'll clear out to New Zealand and Patagonia and the New Zealand Government has been attracting that class for decades.

Many a survival shelter constructed, so they think.

Others think otherwise . . . https://les7eb.substack.com/p/what-lies-beneath-chronicle-of-fools

Free to subscribe.

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Well, you have got yourself into a tizz, haven't you?

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I read the Guardian article again and I agree it is lacks substance.

As for the yields, I am not so sure. Yields have increased over the decades, but now variants are needed the are heat resistant, drought resistant, and flooding resistant. According to prof. Viola Willemsen at the Wageningen University, involved in this kind of research, it takes decades to develop a crop that meets one of these requirements, and to have all three properties is almost impossible.


I am not a specialist in this field and I don’t have the time to figure it all out, but it seems to me that some caution about future crop yields is advisable.

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