That sums it up pretty well. CO2 is only one factor for plant growth. CO2 concentration vs rate of photosynthesis is also asymptotic, where increasing CO2 has diminishing returns for plant growth. C4 photosynthesis plants are already very efficient at using CO2, so they won't increase their photosynthetic rate with higher CO2 concentrations barely at all (as David mentioned.)
In animal respiration, a reciprocal process to photosynthesis, higher oxygen concentrations don't necessarily make humans grow better. High oxygen concentration can even be harmful.
Plants and animals are both well-adapted to current conditions, and when those conditions change too fast, things can get weird.
I think you're misunderstanding the "CO2 is plant food" argument. No one disputes that plants take up CO2 when they grow. The "CO2 is plant food" argument is really making the argument that burning fossil fuels and releasing CO2 is good for plants. The evidence disagrees with that point.
The argument is that higher CO2 helps plants grow & to better resist disease/drought, etc. That human activity adds CO2 is not disputed, nor that the Earth is getting warmer. What's disputed is whether the human contribution makes much difference and whether it's catastrophic.
I love your use of "climate denier" and "zombie". Class act.
In the real world where I live, it's not going to get you very far by calling professional, doctorate level scientists such as myself (I'm a medical doctor) "climate denier zombies" for stating very obvious facts that are objectively seen in the real world. Like crop yields. You name them: Wheat, corn, soybean, etc.
Instead, you link to an article in Nature Climate Change that admits that crop yields are increasing but uses a model to produce "counterfactual climate scenarios" to show that despite all these great yield increases, climate change has reduced "what could have been" by 21% since 1961.
Wow. I feel sorry for you, the authors, the journal, and anyone who quotes this article. First of all, how on earth are you going to reproduce the findings? Based on what real world observations? Second, this study is amazingly devoid of actual scientific principles. All based on modeling, which aren't actual observations. And using counterfactual arguments. Ahh, what could have been! You don't invest in stock much, do you?
The terminology is instructive, especially the "denier" part, with it's holocaust connotations. Falsehoods usually lose an argument, but with the enthusiastic support of a puppet media, such blatant lies as "Climate Denier" persist.
Oh, for - not this again! The argument that "denier" in the context of climate change must always imply "Holocaust denier", is nothing but a cheap rhetorical tactic. It's transparently playing the victim card. Don't you understand you're not the victims here?
First: "deny", "denier", and "denial" are all well defined English language words, independently of what's being denied. If you're looking for Prof. Dessler's lexicographic authority, here's Wikipedia on denialism: (en.wikipedia.org/wiki/Denialism):
"In the sciences, denialism is the rejection of basic facts and concepts that are undisputed, well-supported parts of the scientific consensus on a subject, in favor of ideas that are radical, controversial, or fabricated.[3] The terms Holocaust denial and AIDS denialism describe the denial of the facts and the reality of the subject matters,[4] and the term climate change denial describes denial of the scientific consensus that the climate change of planet Earth is a real and occurring event primarily caused in geologically recent times by human activity.[5] The forms of denialism present the common feature of the person rejecting overwhelming evidence and trying to generate political controversy in attempts to deny the existence of consensus.[6][7]"
Wikipedia isn't always correct, but it will be the top hit on an Internet search for "denialism". That page really ought to put an end to butthurt complaints from climate-disaster deniers about being unfairly accused of Nazism!
Second: "zombie" is an obvious metaphor for "a repeatedly appearing claim that's long since been definitively, iteratively rebutted". "CO2 is plant food" is the 43rd-most-popular zombie denialist claim, among 200 such claims in the SkepticalScience.com database.
So, Scott and Icepilot: if you post climate-disaster-denialist nonsense, you're a "climate-denier". If you don't like being called that, all you have to do is stop propagating risible fallacies in public. If you insist on denying that anthropogenic climate change has already cost some people their homes, livelihoods and even lives, that would not have been lost but for socialized climate change, then at least have the grace to come up with a brand new specious argument!
[Edited to address the zombie denialist argument that "rising per-capita income has saved more lives than have been lost to anthropogenic climate change!"]
I love this. Truly. Especially the part where "Mal-Adapted" provided the scientific research supporting the claim that crop yields are decreasing due to climate change. Oh, that's right--he/she has none. Zero. Nada. I, on the other hand, have given two of many studies revealing the cold hard truth about crop yields: They are increasing. So--if I'm the only one posting scientific research here, how am I the one who is a "climate disaster denialist"? Fascinating! This is why nobody will do any public debates anymore--the alarmists have nothing to support their catastrophic views.
Oh, you could quote Dresslers studies--let's see--Nature climate change using "counterfactuals" (AKA we can't show that everything is getting better so we'll use magic that will never be reproduceable in the real world to show that without global warming crops yields would be 21% greater--pure poppycock), or the PLOS article which basically does the same thing. "Crop yields are already lower due to climate change" but again using counterfactual argument.
Not to be left out, the Nature Communications article is yet another modeling study that has no real basis in reality. It's almost like I'm watching the movie "La La Land" part 2.
Again back in the real world, please review the links I provided. They are real world assessments of crop yields. Shout out to Our World In Data for actually being objective about it.
Am I a denialist if I concur that the earth is warming over time, CO2 has some to do with it, and CO2 is a byproduct of fossil fuel consumption? But suddenly I'm now a denialist if I don't concur that this warm earth is now an existential threat to humanity? Seriously?
Which brings up the question: If all the anecdotal media stories of fires and death are true and we are living the catastrophe right now, which period of "coldness" is required for earth to live in to prosper? The middle ages? The 1700's? 1800's? Someone please answer this!
Scott, Andrew has already considered your arguments on their merits and rejected them, with links to his sources. I'm merely backing him up, drawing on my reading of the same sources, and a long history of tedious encounters with Dunning-Kruger victims on the Internet. I see no need to cite those sources again.
When Andrew used the phrase "zombie climate-denier" at the top of this page, you took ostentatious offense. I cited that default repository of conventional wisdom, Wikipedia, to back up Andrew's usage in this context. I merely demonstrated that it's an apt, easily understood, partly-figurative description for people who persist in making the "CO2 is plant food" argument, no matter how often it's exposed as motivated rhetoric propagated by mercenary opponents of decarbonization, and their useful idiots. Your argument is with Wikipedia, not with Andrew or me.
Look, nobody likes to be told they're fooling themselves. But your phony outrage at the denialist label is transparently strategic. What you yourself are denying, is that anthropogenic climate change is already an "existential threat" to its victims to date, and will be for increasing numbers of people until fossil carbon emissions cease. Whether climate change is an "existential threat to humanity" depends entirely on how much fossil carbon accumulates in the atmosphere before the global economy reaches net-zero, which in turn depends largely on the pace of collective intervention in the global energy market, to take the profit out of selling fossil carbon.
You know damn well that tens of billions of dollars in *annual* profits from the sale of fossil carbon (iea.org/reports/world-energy-investment-2023/overview-and-key-findings) are a powerful motivator to invest in forestalling collective intervention in them, by paying professional disinformers to rebunk long-debunked denialist claims like "CO2 is plant food" on public fora (I already linked to SkepticalScience.com). My sources for the financial drivers of climate disinformation are well-known also, e.g. "Dark Money" by Jane Mayer (en.wikipedia.org/wiki/Jane_Mayer). Shouldn't the long public record of deceptive propaganda from fossil fuel producers and investors, at least give you some cognitive dissonance?
But of course you're doubling down on your denialism. Deniers deny! My appeal is therefore to the hypothetical uncommitted but genuinely skeptical lurker. Thanks for reading, y'all!
In other words, what you are saying is neither you nor Dressler have anything in regards to scientific research to refute the fact that, sadly, crop yields are higher than they ever been due to ADAPTATION. Malnutrition is lower than This would be hilarious if it weren't so sad.
Spoiler alert: I'm a medical doctor with zero fossil fuel interests or connections. I'm just a guy who likes to point out common sense when he sees it.
Do me a favor: Please don't stop your "denialist" crusade. It will make the abrupt end to climate hysteria that much sweeter. Thanks,
I was saying global malnutrition deaths are lower than ever as well. Don't forget infectious disease too. It's getting really hard to prop up the narrative...
Okay - "CO2 is plant food" is a dumb argument. There are other dumb arguments advanced by people who oppose action on climate change; I can think of "CO2 is less than half of a tenth of a percent of the atmosphere, and most advocates don't even know that." CO2 is a small percentage, but that doesn't mean it's unimportant.
But there are plenty of dumb arguments advanced by advocates for drastic decarbonization to prevent climate change:
- "Climate change is already causing hugely increased deaths from heat waves." The truth is that deaths from heat waves have been decreasing because the world has been getting richer, and richer people can cope with heat better than poorer people.
- "Solar and wind renewables are already making energy less expensive." The truth is that solar and wind renewables are more expensive than conventional power generation for nearly all applications and locations.
- "We could build a zero-carbon energy system now, and the only thing stopping it is the evil machinations of the evil fossil fuel companies and their evil, misguided minions." The truth is that there are only vague ideas of how to build a dependable power system. There's been only one attempt I know of to build such a system at a level higher than a single house, and it has not been able to deliver more than half of its electricity (and none of its transportation fuels) from renewables.
- "Science has proven that we face civilizational collapse unless we stop climate change." The truth is that there are no such scientific claims; the non-scientists who make such claims are over-reading science in the most tendentious way possible.
We'd all be better off if we could make better arguments. Most of the public discussion seems designed to make the public dumber.
Brian, you start out like a genuine skeptic, conceding the OP's specific point, and recognizing at least some dumb arguments that are repeatedly rebunked by both cynical and fanatical opponents of decarbonization.
You then deflect to "plenty of dumb arguments advanced by advocates for drastic decarbonization to prevent climate change". Prof. Dessler's OP isn't about other arguments, but specifically and explicitly about the "CO2 is plant food" denialist meme. He's not responsible for dumb, random pro-decarbonization arguments.
You go on to explicitly rebunk other dumb, revenant denialist memes. I'll take the time to respond to each, providing links to peer-reviewed analyses where needed. If it's tl;dr, skip it, but this is the best I can do, and I probably won't respond to further denialism.
- "The truth is that deaths from heat waves have been decreasing because the world has been getting richer, and richer people can cope with heat better than poorer people.":
No. The upward trend of heatwave mortality specifically attributable to global warming is verifiable (pmc.ncbi.nlm.nih.gov/articles/PMC7611104/pdf/EMS127821.pdf). To be clear: these are deaths that would not have occurred if the globe wasn't warming due to anthropogenic greenhouse emissions.
- "The truth is that solar and wind renewables are more expensive than conventional power generation for nearly all applications and locations."
That's obviously false, given the precipitous decline in LCOE from solar and wind power around the world, and the consequent explosive growth in supplies, cited previously by Prof. Dessler inter alia. There's no point in citing them again!
- "'We could build a zero-carbon energy system now, and the only thing stopping it is the evil machinations of the evil fossil fuel companies and their evil, misguided minions'. The truth is that there are only vague ideas of how to build a dependable power system."
Hmm. I haven't seen Prof. Dessler make the claim you're quoting, certainly not in so many words, depending on what you mean by "now" and "evil". He has called for public investment in ramping up renewables+storage capacity, to drive the required learning curves more rapidly. I call your quote a straw man.
Sure, it's legal to purchase public disinformation and extort elected officials in today's America. Hell, from their POV, carbon capitalists would be fools not to invest in thwarting collective intervention in their profit streams. Yet those who do, know perfectly well their positive ROI exacerbates the biggest tragedy of the commons in history. Should they be punished somehow? Good luck with that in today's America! I'd be satisfied just to take the profit out of selling fossil carbon, by taxing it, regulating emissions directly, or subsidizing renewables and storage development. Would you call cutting fossil-fuel investors' profits out from under them by making renewable energy cheaper and more available globally, "evil"?
- "'Science has proven that we face civilizational collapse unless we stop climate change.' The truth is that there are no such scientific claims; the non-scientists who make such claims are over-reading science in the most tendentious way possible."
You're correct as stated. Yet I submit you're carping off-topic in a tendentious way yourself. Again, since you brought it up: even non-scientists can recognize that the upward trend of global heat content, and the worsening of various weather extremes resulting in increasing cost in money and/or grief, are *open-ended* until the global economy is fully decarbonized. The conclusion proceeds from both changing weather statistics and simple physics. The cost of adaptation must be included, even with higher prosperity, because the money spent on adaptation would be better spent on other public goods ("opportunity cost"). And future prosperity will depend on capping the costs of climate change, by decoupling economic growth from fossil carbon emissions. That might take decades, but the human and biodiversity costs will mount relentlessly until it's completed.
Asking for numbers is beside the point. It's inarguable that past fossil carbon consumption has driven economic development and improved the lot of billions. It's also inarguable that the deferred, socialized cost of all that carbon sold on the global "free" market is now being paid disproportionately by involuntary third parties, and will mount without bound until carbon-neutral energy replaces fossil fuels. Renewable energy can do so, over some period of time, with some level of collective intervention. Until it does, the socialized cost of our aggregate emissions will rise without bound. How high will it get, before a new equilibrium climate is reached? How high do you want it?
- "Most of the public discussion seems designed to make the public dumber."
Yes. IMHO, you're not helping. Not saying you're evil, just misguided. Where I have doubts, I'll rely on the scientific consensus. Thankfully, neither of us is responsible for "the public".
Thanks for taking the time to respond in detail. Your response deserves an equally detailed answer.
On heat waves, I should perhaps have been more detailed. Your source on says that the deaths from heat over the time from 1991 to 2018 would have been lower if there hadn't been any warming. Without endorsing the findings or methods of this story, I will agree that this claim should be true. When I said deaths from heatwaves have been decreasing, however, I was thinking of a multi-decade time horizon, and all deaths from heatwaves, not the portion of deaths from heatwaves "directly attributable to global warming." My claim is that increasing prosperity has allowed things like air conditioning, less exposure to extreme physical exertion, better medical treatment, and other things that have combined to significantly reduce deaths from heat. Data is spotty, and not necessarily consistent from one area to another, but there is data to support this idea. For instance, this study (https://pmc.ncbi.nlm.nih.gov/articles/PMC4096340/) estimates that heat-related mortality risk New York City declined by about 20% from 1900 to 2000. Another study (https://www.sciencedirect.com/science/article/pii/S1462901114000999) looked at Australia, and found that deaths from heat and death rates both declined substantially from the mid 19th century through 2010. I think this is true of most of the impacts of warming - the modern economy we have has made life better in just about every sense. This economy was only possible because of the energy used, which mostly came from fossil fuels, which in turn had their own downsides. Eliminating the fossil fuels to eliminate the downsides would put us back to an 18th or 19th century standard of living. No rich country is willing to do that, and especially no poor country is willing to give up the chance for a modern economy in order to prevent further warming.
Decreasing costs for renewables does not mean that costs have gotten below conventional generation costs. I have reservations about the methodology used by the Lazard LCOE study. As I noted elsewhere (https://www.theclimatebrink.com/p/an-explanation-of-how-renewable-energy/comment/89522976), the history with estimates like these is that there's generally some hidden assumption or caveat that undercuts the face value of the conclusion. I couldn't find these in the latest Lazard study, but they also never acknowledged them in the past, and they didn't explain how such assumptions are no longer needed, so I assume the assumptions are still there, but left unstated. To substantiate this claim, I noted in the same comment that Germany, Spain, and California are already experiencing substantial periods of negative wholesale generation prices - these indicate that current nondispatchable generation is already higher than can be used by the grid, which means some of the power generated is wasted, which means that even in current grids the LCOE calculation is blown up because costs are decreased when generated power is wasted. Furthermore, in the same comment I noted that Lazard's treatment of capital cost doesn't seem to make sense - their LCOE estimate is not very sensitive to interest rates, but interest rates should be the biggest driver of LCOE; higher interest rates mean higher LCOE. Other estimates have explicitly noted that assumptions about economic viability are heavily dependent on the extremely low interest rates seen from 2008 to 2020. As I noted there, I've written the Lazard contacts to ask about this issue, but they haven't responded. As further substantiation, there were many stories a few years ago about US wind projects being cancelled due to higher financing costs when interest rates rose. Furthermore, most of the "plans" to implement a zero-carbon energy system explicitly rely on subsidies and legal mandates to drive implementation of renewables, electric vehicles, and other parts of the envisioned system.
As far as the feasibility of a zero-carbon energy system, Professor Dessler has made this claim repeatedly, in several posts on this Substack. For instance, here (https://www.theclimatebrink.com/p/an-explanation-of-how-renewable-energy), where he says that renewables are decreasing wholesale electricity price in Texas, without addressing the fact that the federal government pays part of the cost of building and operating renewable facilities. Texans may get lower wholesale prices, but they're paying part of the bill through their taxes. Then there's here (https://www.theclimatebrink.com/p/is-renewable-energy-cheaper-than), where he cites LCOE studies, and also cites an NREL study (https://www.sciencedirect.com/science/article/pii/S2542435121002464) that forecasts that the lowest-cost system in 2050 will have 57% renewables. He does acknowledge the 2050 date, but implies that this is true now, and doesn't acknowledge that this forecast depends on assumptions about continued cost declines for renewables. The assumptions may (or may not) be plausible, but they're not established facts. He also cites studies like the Berkeley 2035 project or Princeton Net Zero America to show there's a feasible path to a zero-carbon (or nearly zero-carbon) energy system, but these studies are clear that the cost will be much higher than our current energy system, and the Princeton study explicitly relies on a technology (large-scale carbon capture and sequestration) that does not yet exist.
I won't really address the application of "evil" to publication of ideas that you, or I, disagree with. But you seem to assume that millions of dollars of "propaganda" can derail the established truth of the environmentally astute. Why would this be true? The funded and supported material in support of the catastrophist narrative is much greater than that questioning it. If money is deciding the issue, then your narrative has already won. Of course, many people assume that campaign funding defines election results, not even acknowledging that higher-funded candidates often lose, either because they're bad candidates, or because the electorate just doesn't accept them.
As far as the last item, I think I fairly stated Professor Dessler's position, assuming he either wrote or supports the purpose of the Substack, as stated under "What is the Climate Brink?" "We currently find ourselves standing at the edge of two very different brinks. One represents the disastrous consequences of unmitigated climate change, and the other represents the hope of innovative solutions, renewable energy, and a sustainable future." (https://www.theclimatebrink.com/about) If you think I was unfair, how do you read the statement of purpose?
You claim that various weather extremes have gotten worse, This claim is often made in the popular media. But that claim is not supported by the reports of the IPCC - in area after area (droughts, floods, tropical cyclones, agricultural yields, etc.) they report that model outputs suggest negative consequences (not disastrous consequences), but that there's no clear evidence these have yet appeared. One might even think that the pro-catastrophe camp has been running a "pro-decarbonization propaganda machine."
I don't expect to change your mind. But I think you deserve a thoughtful, fact-based response why I think the way I do. And if Professor Dessler wants to contribute to useful public discussion, he should really up his game.
'"There's been only one attempt I know of to build such a system at a level higher than a single house, and it has not been able to deliver more than half of its electricity (and none of its transportation fuels) from renewables."
Even more impressive. Achieving 70%+ from solar and wind would seem to refute the arguments made that the grid becomes unstable if nondispatchable renewables get above 25-30%.
For myself, an important question is "what atmospheric CO2 level should we be targeting?" If the natural sinks continue to perform much as they have in the past, with removals that are directly proportional to atmospheric levels, the goal of "net zero" by 2050 would take us to significantly lower atmospheric levels by the end of the century than Dr. James Hansen's target (350 ppm CO2). I know that there is uncertainty about how the sinks will respond as emissions are reduced -- in particular, we don't fully understand the transport of dissolved carbon in the oceans -- but we still need a target and the ability to assess progress against the target.
"In many commercial greenhouses, CO₂ levels are often enriched to about 1,000 parts per million (ppm) to optimize plant growth, compared to the ambient level of roughly 400 ppm".
Seems to me that satellite photos show that the planet is actually getting greener with these moderately elevated CO2 levels. I accept that CO2 isn't the only metric affecting plant growth but satellite photos seem pretty convincing.
Photosynthesis: Plants/Plankton turning Sunlight/CO2/H2O into Food/O2; neither animal nor blade of grass would exist, absent CO2. CO2 helps plants resist drought/damage/disease, extends growing seasons, lets plants move higher in altitude & Latitudes, shrinks deserts & reduces the spread of fire, plants using & retaining H2O more efficiently. As CO2 rises, photosynthesis flourishes & plants take in more CO2, sparking more growth, photosynthesis & CO2 uptake (recent studies indicate +20% absorption by 2100). Rising temperatures also extend growing seasons, help babies survive, increase net rainfall & save lives. We are in the short period (glacial interstitial) between long Ice Ages, the norm (where I sit) being a half mile of ice. Warm is good, cold is bad. This Cradle of Life is greener, more fertile & life sustaining than it was 200 years ago, because adding food to the base of the food-chain supports all of Nature, including humans. "It will be remembered as the greatest mass delusion in the history of the world – that CO2, the life of plants, was considered for a time to be a deadly poison." R Lindzen
I seem to recall some work showing that crops grown in high CO2 environments (in greenhouses, for example) have altered nutritional content - increases in starches and sugars but dilution of proteins and minerals. Found a few papers from around 2018; is there more recent work on the topic?
Here's a long Bluesky thread on this subject: https://bsky.app/profile/paulmac.bsky.social/post/3leg7fhrqjs2e
That sums it up pretty well. CO2 is only one factor for plant growth. CO2 concentration vs rate of photosynthesis is also asymptotic, where increasing CO2 has diminishing returns for plant growth. C4 photosynthesis plants are already very efficient at using CO2, so they won't increase their photosynthetic rate with higher CO2 concentrations barely at all (as David mentioned.)
In animal respiration, a reciprocal process to photosynthesis, higher oxygen concentrations don't necessarily make humans grow better. High oxygen concentration can even be harmful.
Plants and animals are both well-adapted to current conditions, and when those conditions change too fast, things can get weird.
Great reminder!
Great article, thanks. This covers that myth too https://youtu.be/lPF-6d7_oyg?si=PLb6XjnD1MzHHs61
This article and the video don’t debunk the myth.
Your arguments are:
1. The world is also greening from other causes
2. Climate change is bad
3. Plants also need other things besides CO2 to grow
These arguments are perfectly compatible with “CO2 is food.”
What they’re incompatible with is “and therefore CO2 is good for climate.”
I think you're misunderstanding the "CO2 is plant food" argument. No one disputes that plants take up CO2 when they grow. The "CO2 is plant food" argument is really making the argument that burning fossil fuels and releasing CO2 is good for plants. The evidence disagrees with that point.
No.
The argument is that higher CO2 helps plants grow & to better resist disease/drought, etc. That human activity adds CO2 is not disputed, nor that the Earth is getting warmer. What's disputed is whether the human contribution makes much difference and whether it's catastrophic.
Andrew, what evidence do you have other than a modeling study using counterfactual scenarios "AKA not tethered to reality"? just curious
Hi Andrew,
I love your use of "climate denier" and "zombie". Class act.
In the real world where I live, it's not going to get you very far by calling professional, doctorate level scientists such as myself (I'm a medical doctor) "climate denier zombies" for stating very obvious facts that are objectively seen in the real world. Like crop yields. You name them: Wheat, corn, soybean, etc.
https://farmdocdaily.illinois.edu/2023/12/world-and-regional-trend-crop-yields-in-an-era-of-climate-change.html
https://ourworldindata.org/crop-yields-climate-impact#:~:text=The%20chart%20below%20shows%20the%20actual%20change%20in%20crop%20yields,irrigation%2C%20and%20better%20farming%20practices.
Instead, you link to an article in Nature Climate Change that admits that crop yields are increasing but uses a model to produce "counterfactual climate scenarios" to show that despite all these great yield increases, climate change has reduced "what could have been" by 21% since 1961.
Wow. I feel sorry for you, the authors, the journal, and anyone who quotes this article. First of all, how on earth are you going to reproduce the findings? Based on what real world observations? Second, this study is amazingly devoid of actual scientific principles. All based on modeling, which aren't actual observations. And using counterfactual arguments. Ahh, what could have been! You don't invest in stock much, do you?
The terminology is instructive, especially the "denier" part, with it's holocaust connotations. Falsehoods usually lose an argument, but with the enthusiastic support of a puppet media, such blatant lies as "Climate Denier" persist.
Oh, for - not this again! The argument that "denier" in the context of climate change must always imply "Holocaust denier", is nothing but a cheap rhetorical tactic. It's transparently playing the victim card. Don't you understand you're not the victims here?
First: "deny", "denier", and "denial" are all well defined English language words, independently of what's being denied. If you're looking for Prof. Dessler's lexicographic authority, here's Wikipedia on denialism: (en.wikipedia.org/wiki/Denialism):
"In the sciences, denialism is the rejection of basic facts and concepts that are undisputed, well-supported parts of the scientific consensus on a subject, in favor of ideas that are radical, controversial, or fabricated.[3] The terms Holocaust denial and AIDS denialism describe the denial of the facts and the reality of the subject matters,[4] and the term climate change denial describes denial of the scientific consensus that the climate change of planet Earth is a real and occurring event primarily caused in geologically recent times by human activity.[5] The forms of denialism present the common feature of the person rejecting overwhelming evidence and trying to generate political controversy in attempts to deny the existence of consensus.[6][7]"
Wikipedia isn't always correct, but it will be the top hit on an Internet search for "denialism". That page really ought to put an end to butthurt complaints from climate-disaster deniers about being unfairly accused of Nazism!
Second: "zombie" is an obvious metaphor for "a repeatedly appearing claim that's long since been definitively, iteratively rebutted". "CO2 is plant food" is the 43rd-most-popular zombie denialist claim, among 200 such claims in the SkepticalScience.com database.
So, Scott and Icepilot: if you post climate-disaster-denialist nonsense, you're a "climate-denier". If you don't like being called that, all you have to do is stop propagating risible fallacies in public. If you insist on denying that anthropogenic climate change has already cost some people their homes, livelihoods and even lives, that would not have been lost but for socialized climate change, then at least have the grace to come up with a brand new specious argument!
[Edited to address the zombie denialist argument that "rising per-capita income has saved more lives than have been lost to anthropogenic climate change!"]
I love this. Truly. Especially the part where "Mal-Adapted" provided the scientific research supporting the claim that crop yields are decreasing due to climate change. Oh, that's right--he/she has none. Zero. Nada. I, on the other hand, have given two of many studies revealing the cold hard truth about crop yields: They are increasing. So--if I'm the only one posting scientific research here, how am I the one who is a "climate disaster denialist"? Fascinating! This is why nobody will do any public debates anymore--the alarmists have nothing to support their catastrophic views.
Oh, you could quote Dresslers studies--let's see--Nature climate change using "counterfactuals" (AKA we can't show that everything is getting better so we'll use magic that will never be reproduceable in the real world to show that without global warming crops yields would be 21% greater--pure poppycock), or the PLOS article which basically does the same thing. "Crop yields are already lower due to climate change" but again using counterfactual argument.
Not to be left out, the Nature Communications article is yet another modeling study that has no real basis in reality. It's almost like I'm watching the movie "La La Land" part 2.
Again back in the real world, please review the links I provided. They are real world assessments of crop yields. Shout out to Our World In Data for actually being objective about it.
Am I a denialist if I concur that the earth is warming over time, CO2 has some to do with it, and CO2 is a byproduct of fossil fuel consumption? But suddenly I'm now a denialist if I don't concur that this warm earth is now an existential threat to humanity? Seriously?
Which brings up the question: If all the anecdotal media stories of fires and death are true and we are living the catastrophe right now, which period of "coldness" is required for earth to live in to prosper? The middle ages? The 1700's? 1800's? Someone please answer this!
Scott, Andrew has already considered your arguments on their merits and rejected them, with links to his sources. I'm merely backing him up, drawing on my reading of the same sources, and a long history of tedious encounters with Dunning-Kruger victims on the Internet. I see no need to cite those sources again.
When Andrew used the phrase "zombie climate-denier" at the top of this page, you took ostentatious offense. I cited that default repository of conventional wisdom, Wikipedia, to back up Andrew's usage in this context. I merely demonstrated that it's an apt, easily understood, partly-figurative description for people who persist in making the "CO2 is plant food" argument, no matter how often it's exposed as motivated rhetoric propagated by mercenary opponents of decarbonization, and their useful idiots. Your argument is with Wikipedia, not with Andrew or me.
Look, nobody likes to be told they're fooling themselves. But your phony outrage at the denialist label is transparently strategic. What you yourself are denying, is that anthropogenic climate change is already an "existential threat" to its victims to date, and will be for increasing numbers of people until fossil carbon emissions cease. Whether climate change is an "existential threat to humanity" depends entirely on how much fossil carbon accumulates in the atmosphere before the global economy reaches net-zero, which in turn depends largely on the pace of collective intervention in the global energy market, to take the profit out of selling fossil carbon.
You know damn well that tens of billions of dollars in *annual* profits from the sale of fossil carbon (iea.org/reports/world-energy-investment-2023/overview-and-key-findings) are a powerful motivator to invest in forestalling collective intervention in them, by paying professional disinformers to rebunk long-debunked denialist claims like "CO2 is plant food" on public fora (I already linked to SkepticalScience.com). My sources for the financial drivers of climate disinformation are well-known also, e.g. "Dark Money" by Jane Mayer (en.wikipedia.org/wiki/Jane_Mayer). Shouldn't the long public record of deceptive propaganda from fossil fuel producers and investors, at least give you some cognitive dissonance?
But of course you're doubling down on your denialism. Deniers deny! My appeal is therefore to the hypothetical uncommitted but genuinely skeptical lurker. Thanks for reading, y'all!
Hi Mal,
In other words, what you are saying is neither you nor Dressler have anything in regards to scientific research to refute the fact that, sadly, crop yields are higher than they ever been due to ADAPTATION. Malnutrition is lower than This would be hilarious if it weren't so sad.
Spoiler alert: I'm a medical doctor with zero fossil fuel interests or connections. I'm just a guy who likes to point out common sense when he sees it.
Do me a favor: Please don't stop your "denialist" crusade. It will make the abrupt end to climate hysteria that much sweeter. Thanks,
I was saying global malnutrition deaths are lower than ever as well. Don't forget infectious disease too. It's getting really hard to prop up the narrative...
Okay - "CO2 is plant food" is a dumb argument. There are other dumb arguments advanced by people who oppose action on climate change; I can think of "CO2 is less than half of a tenth of a percent of the atmosphere, and most advocates don't even know that." CO2 is a small percentage, but that doesn't mean it's unimportant.
But there are plenty of dumb arguments advanced by advocates for drastic decarbonization to prevent climate change:
- "Climate change is already causing hugely increased deaths from heat waves." The truth is that deaths from heat waves have been decreasing because the world has been getting richer, and richer people can cope with heat better than poorer people.
- "Solar and wind renewables are already making energy less expensive." The truth is that solar and wind renewables are more expensive than conventional power generation for nearly all applications and locations.
- "We could build a zero-carbon energy system now, and the only thing stopping it is the evil machinations of the evil fossil fuel companies and their evil, misguided minions." The truth is that there are only vague ideas of how to build a dependable power system. There's been only one attempt I know of to build such a system at a level higher than a single house, and it has not been able to deliver more than half of its electricity (and none of its transportation fuels) from renewables.
- "Science has proven that we face civilizational collapse unless we stop climate change." The truth is that there are no such scientific claims; the non-scientists who make such claims are over-reading science in the most tendentious way possible.
We'd all be better off if we could make better arguments. Most of the public discussion seems designed to make the public dumber.
Brian, you start out like a genuine skeptic, conceding the OP's specific point, and recognizing at least some dumb arguments that are repeatedly rebunked by both cynical and fanatical opponents of decarbonization.
You then deflect to "plenty of dumb arguments advanced by advocates for drastic decarbonization to prevent climate change". Prof. Dessler's OP isn't about other arguments, but specifically and explicitly about the "CO2 is plant food" denialist meme. He's not responsible for dumb, random pro-decarbonization arguments.
You go on to explicitly rebunk other dumb, revenant denialist memes. I'll take the time to respond to each, providing links to peer-reviewed analyses where needed. If it's tl;dr, skip it, but this is the best I can do, and I probably won't respond to further denialism.
- "The truth is that deaths from heat waves have been decreasing because the world has been getting richer, and richer people can cope with heat better than poorer people.":
No. The upward trend of heatwave mortality specifically attributable to global warming is verifiable (pmc.ncbi.nlm.nih.gov/articles/PMC7611104/pdf/EMS127821.pdf). To be clear: these are deaths that would not have occurred if the globe wasn't warming due to anthropogenic greenhouse emissions.
- "The truth is that solar and wind renewables are more expensive than conventional power generation for nearly all applications and locations."
That's obviously false, given the precipitous decline in LCOE from solar and wind power around the world, and the consequent explosive growth in supplies, cited previously by Prof. Dessler inter alia. There's no point in citing them again!
- "'We could build a zero-carbon energy system now, and the only thing stopping it is the evil machinations of the evil fossil fuel companies and their evil, misguided minions'. The truth is that there are only vague ideas of how to build a dependable power system."
Hmm. I haven't seen Prof. Dessler make the claim you're quoting, certainly not in so many words, depending on what you mean by "now" and "evil". He has called for public investment in ramping up renewables+storage capacity, to drive the required learning curves more rapidly. I call your quote a straw man.
And since you've opened the topic of evil for discussion: whether or not Andrew has used the word, I call investing millions of dollars annually in anti-decarbonization propaganda engines like The Heartland Institute and the Heritage Foundation (link.springer.com/article/10.1007/s10584-013-1018-7) "evil", from a nuanced, adult perspective! And how about them Koch brothers, ain't they sump'n (forbes.com/sites/danielfisher/2012/12/05/inside-the-koch-empire-how-the-brothers-plan-to-reshape-america; newyorker.com/news/daily-comment/kochland-examines-how-the-koch-brothers-made-their-fortune-and-the-influence-it-bought)? Are they less evil because they haven't achieved all their self-interested goals?
Sure, it's legal to purchase public disinformation and extort elected officials in today's America. Hell, from their POV, carbon capitalists would be fools not to invest in thwarting collective intervention in their profit streams. Yet those who do, know perfectly well their positive ROI exacerbates the biggest tragedy of the commons in history. Should they be punished somehow? Good luck with that in today's America! I'd be satisfied just to take the profit out of selling fossil carbon, by taxing it, regulating emissions directly, or subsidizing renewables and storage development. Would you call cutting fossil-fuel investors' profits out from under them by making renewable energy cheaper and more available globally, "evil"?
- "'Science has proven that we face civilizational collapse unless we stop climate change.' The truth is that there are no such scientific claims; the non-scientists who make such claims are over-reading science in the most tendentious way possible."
You're correct as stated. Yet I submit you're carping off-topic in a tendentious way yourself. Again, since you brought it up: even non-scientists can recognize that the upward trend of global heat content, and the worsening of various weather extremes resulting in increasing cost in money and/or grief, are *open-ended* until the global economy is fully decarbonized. The conclusion proceeds from both changing weather statistics and simple physics. The cost of adaptation must be included, even with higher prosperity, because the money spent on adaptation would be better spent on other public goods ("opportunity cost"). And future prosperity will depend on capping the costs of climate change, by decoupling economic growth from fossil carbon emissions. That might take decades, but the human and biodiversity costs will mount relentlessly until it's completed.
Asking for numbers is beside the point. It's inarguable that past fossil carbon consumption has driven economic development and improved the lot of billions. It's also inarguable that the deferred, socialized cost of all that carbon sold on the global "free" market is now being paid disproportionately by involuntary third parties, and will mount without bound until carbon-neutral energy replaces fossil fuels. Renewable energy can do so, over some period of time, with some level of collective intervention. Until it does, the socialized cost of our aggregate emissions will rise without bound. How high will it get, before a new equilibrium climate is reached? How high do you want it?
- "Most of the public discussion seems designed to make the public dumber."
Yes. IMHO, you're not helping. Not saying you're evil, just misguided. Where I have doubts, I'll rely on the scientific consensus. Thankfully, neither of us is responsible for "the public".
Thanks for taking the time to respond in detail. Your response deserves an equally detailed answer.
On heat waves, I should perhaps have been more detailed. Your source on says that the deaths from heat over the time from 1991 to 2018 would have been lower if there hadn't been any warming. Without endorsing the findings or methods of this story, I will agree that this claim should be true. When I said deaths from heatwaves have been decreasing, however, I was thinking of a multi-decade time horizon, and all deaths from heatwaves, not the portion of deaths from heatwaves "directly attributable to global warming." My claim is that increasing prosperity has allowed things like air conditioning, less exposure to extreme physical exertion, better medical treatment, and other things that have combined to significantly reduce deaths from heat. Data is spotty, and not necessarily consistent from one area to another, but there is data to support this idea. For instance, this study (https://pmc.ncbi.nlm.nih.gov/articles/PMC4096340/) estimates that heat-related mortality risk New York City declined by about 20% from 1900 to 2000. Another study (https://www.sciencedirect.com/science/article/pii/S1462901114000999) looked at Australia, and found that deaths from heat and death rates both declined substantially from the mid 19th century through 2010. I think this is true of most of the impacts of warming - the modern economy we have has made life better in just about every sense. This economy was only possible because of the energy used, which mostly came from fossil fuels, which in turn had their own downsides. Eliminating the fossil fuels to eliminate the downsides would put us back to an 18th or 19th century standard of living. No rich country is willing to do that, and especially no poor country is willing to give up the chance for a modern economy in order to prevent further warming.
Decreasing costs for renewables does not mean that costs have gotten below conventional generation costs. I have reservations about the methodology used by the Lazard LCOE study. As I noted elsewhere (https://www.theclimatebrink.com/p/an-explanation-of-how-renewable-energy/comment/89522976), the history with estimates like these is that there's generally some hidden assumption or caveat that undercuts the face value of the conclusion. I couldn't find these in the latest Lazard study, but they also never acknowledged them in the past, and they didn't explain how such assumptions are no longer needed, so I assume the assumptions are still there, but left unstated. To substantiate this claim, I noted in the same comment that Germany, Spain, and California are already experiencing substantial periods of negative wholesale generation prices - these indicate that current nondispatchable generation is already higher than can be used by the grid, which means some of the power generated is wasted, which means that even in current grids the LCOE calculation is blown up because costs are decreased when generated power is wasted. Furthermore, in the same comment I noted that Lazard's treatment of capital cost doesn't seem to make sense - their LCOE estimate is not very sensitive to interest rates, but interest rates should be the biggest driver of LCOE; higher interest rates mean higher LCOE. Other estimates have explicitly noted that assumptions about economic viability are heavily dependent on the extremely low interest rates seen from 2008 to 2020. As I noted there, I've written the Lazard contacts to ask about this issue, but they haven't responded. As further substantiation, there were many stories a few years ago about US wind projects being cancelled due to higher financing costs when interest rates rose. Furthermore, most of the "plans" to implement a zero-carbon energy system explicitly rely on subsidies and legal mandates to drive implementation of renewables, electric vehicles, and other parts of the envisioned system.
As far as the feasibility of a zero-carbon energy system, Professor Dessler has made this claim repeatedly, in several posts on this Substack. For instance, here (https://www.theclimatebrink.com/p/an-explanation-of-how-renewable-energy), where he says that renewables are decreasing wholesale electricity price in Texas, without addressing the fact that the federal government pays part of the cost of building and operating renewable facilities. Texans may get lower wholesale prices, but they're paying part of the bill through their taxes. Then there's here (https://www.theclimatebrink.com/p/is-renewable-energy-cheaper-than), where he cites LCOE studies, and also cites an NREL study (https://www.sciencedirect.com/science/article/pii/S2542435121002464) that forecasts that the lowest-cost system in 2050 will have 57% renewables. He does acknowledge the 2050 date, but implies that this is true now, and doesn't acknowledge that this forecast depends on assumptions about continued cost declines for renewables. The assumptions may (or may not) be plausible, but they're not established facts. He also cites studies like the Berkeley 2035 project or Princeton Net Zero America to show there's a feasible path to a zero-carbon (or nearly zero-carbon) energy system, but these studies are clear that the cost will be much higher than our current energy system, and the Princeton study explicitly relies on a technology (large-scale carbon capture and sequestration) that does not yet exist.
I won't really address the application of "evil" to publication of ideas that you, or I, disagree with. But you seem to assume that millions of dollars of "propaganda" can derail the established truth of the environmentally astute. Why would this be true? The funded and supported material in support of the catastrophist narrative is much greater than that questioning it. If money is deciding the issue, then your narrative has already won. Of course, many people assume that campaign funding defines election results, not even acknowledging that higher-funded candidates often lose, either because they're bad candidates, or because the electorate just doesn't accept them.
As far as the last item, I think I fairly stated Professor Dessler's position, assuming he either wrote or supports the purpose of the Substack, as stated under "What is the Climate Brink?" "We currently find ourselves standing at the edge of two very different brinks. One represents the disastrous consequences of unmitigated climate change, and the other represents the hope of innovative solutions, renewable energy, and a sustainable future." (https://www.theclimatebrink.com/about) If you think I was unfair, how do you read the statement of purpose?
You claim that various weather extremes have gotten worse, This claim is often made in the popular media. But that claim is not supported by the reports of the IPCC - in area after area (droughts, floods, tropical cyclones, agricultural yields, etc.) they report that model outputs suggest negative consequences (not disastrous consequences), but that there's no clear evidence these have yet appeared. One might even think that the pro-catastrophe camp has been running a "pro-decarbonization propaganda machine."
I don't expect to change your mind. But I think you deserve a thoughtful, fact-based response why I think the way I do. And if Professor Dessler wants to contribute to useful public discussion, he should really up his game.
'"There's been only one attempt I know of to build such a system at a level higher than a single house, and it has not been able to deliver more than half of its electricity (and none of its transportation fuels) from renewables."
Apparently you are unfamiliar with South Australia, https://explore.openelectricity.org.au/energy/sa1/?range=1y&interval=1w&view=discrete-time&group=Detailed
1-year renewable contribution = 71.7%
30-day renewable contribution = 75.6%
7-day renewable contribution = 76.9%
3-day renewable contribution = 74.8%
1-day renewable contribution = 85.7%
Time stamp = 24 Feb 2025, 12:30 AM AEST.
Very impressive. Is South Australia's system designed to run 100% renewable?
That's where they are headed, target of 100% renewable by 2027.
https://www.energymining.sa.gov.au/consumers/energy-grid-and-supply/our-electricity-supply-and-market
Even more impressive. Achieving 70%+ from solar and wind would seem to refute the arguments made that the grid becomes unstable if nondispatchable renewables get above 25-30%.
Do you know how much South Australia has spent to build this system? This site says the state "has attracted over A$6 billion investment in large-scale renewable energy and storage projects to date" (https://www.energymining.sa.gov.au/industry/hydrogen-and-renewable-energy/leading-the-green-economy). This would equate to about US$3.8 billion, or a bit over US$2,000 per person in the state.
Also, I'll note that South Australia's plan is for "100% net renewable energy by 2027" - implying that they'll still need to import power at times.
Still, a very impressive achievement.
For the past several decades Canada's vast forests have become a "carbon source" rather than a "carbon sink". https://natural-resources.canada.ca/climate-change/forest-carbon
Nailed it!
For myself, an important question is "what atmospheric CO2 level should we be targeting?" If the natural sinks continue to perform much as they have in the past, with removals that are directly proportional to atmospheric levels, the goal of "net zero" by 2050 would take us to significantly lower atmospheric levels by the end of the century than Dr. James Hansen's target (350 ppm CO2). I know that there is uncertainty about how the sinks will respond as emissions are reduced -- in particular, we don't fully understand the transport of dissolved carbon in the oceans -- but we still need a target and the ability to assess progress against the target.
"In many commercial greenhouses, CO₂ levels are often enriched to about 1,000 parts per million (ppm) to optimize plant growth, compared to the ambient level of roughly 400 ppm".
Oops....Darn.
https://tinyurl.com/CO2forplants
https://tinyurl.com/CO2plants2
https://tinyurl.com/CO2forplants3
I'll stop at three.
Seems to me that satellite photos show that the planet is actually getting greener with these moderately elevated CO2 levels. I accept that CO2 isn't the only metric affecting plant growth but satellite photos seem pretty convincing.
Moron. 6CO2 + 6H2O → C6H12O6 + 6O2 + 6H2O
Photosynthesis: Plants/Plankton turning Sunlight/CO2/H2O into Food/O2; neither animal nor blade of grass would exist, absent CO2. CO2 helps plants resist drought/damage/disease, extends growing seasons, lets plants move higher in altitude & Latitudes, shrinks deserts & reduces the spread of fire, plants using & retaining H2O more efficiently. As CO2 rises, photosynthesis flourishes & plants take in more CO2, sparking more growth, photosynthesis & CO2 uptake (recent studies indicate +20% absorption by 2100). Rising temperatures also extend growing seasons, help babies survive, increase net rainfall & save lives. We are in the short period (glacial interstitial) between long Ice Ages, the norm (where I sit) being a half mile of ice. Warm is good, cold is bad. This Cradle of Life is greener, more fertile & life sustaining than it was 200 years ago, because adding food to the base of the food-chain supports all of Nature, including humans. "It will be remembered as the greatest mass delusion in the history of the world – that CO2, the life of plants, was considered for a time to be a deadly poison." R Lindzen
Hi Andrew, talking of plants and food, have you heard this from Rachel Donald and Sailesh Rao? I've been vegan for 10 years, watched cowspiracy etc, but it's blowing even my mind! https://www.planetcritical.com/p/how-to-cool-the-planet-sailesh-rao
I seem to recall some work showing that crops grown in high CO2 environments (in greenhouses, for example) have altered nutritional content - increases in starches and sugars but dilution of proteins and minerals. Found a few papers from around 2018; is there more recent work on the topic?
what do farmers have to say about such things?
More bales of hay per acre.