Zeke, I enjoy reading your writing regardless the topic and do respect the analyses that you have posted earlier. I agree here with your trepidation. I must admit, don't apologise for my age, 80+, but one important ingredient that our Earth lacks today--- is leadership. Humans have a lousy record of change for the greater good. I try to be optimistic for our youngest generation but it is very difficult. I can only hope that they can show us how we should live together.
My favorite allegory of the ignorant arrogance ("arrognorance"? "ignorogance"?) of humanity is "the Sorcerer's Apprentice", from Disney's groundbreaking 1940 film "Fantasia" (https://video.disney.com/watch/sorcerer-s-apprentice-fantasia-4ea9ebc01a74ea59a5867853). Too bad there's no benevolent master sorcerer to rescue us as we circle the drain!
If you think that SRM will lead to less emissions reduction, then you are assuming to will continue to not take climate action seriously. If we continue to "choose to fail", as Kevin Anderson puts it, then we will fail. We should instead assume we will someday choose to succeed. When that day comes, SRM will be an important tool to fight the impacts of climate change and avoid tipping points. It is likely that SRM is *required* very soon in order to avoid tipping points such as an AMOC collapse, since emissions reduction and CDR will take decades to reduce warming and slow the melting of Greenland which produces the fresh water that is contributing to the slowdown of the AMOC. The costs and risks of SRM must be viewed in the context of *not* doing SRM. I believe the risks of not doing SRM greatly outweigh the risks of doing it.
My worry is if folks realize we can effectively postpone climate change for a few billion $ per year, we go down that route and screw over future generations. One thing I've come to realize working on permanent carbon removal for my day job with Stripe/Fronter is the less we need to rely on it, the better off we will be. I'm extremely skeptical of our collective willingness to spend trillions in the future to reverse climate change, vs normalizing the harms to human and natural systems in a warmer future...
Again, you are assuming that we will not take climate action seriously and we will continue (like now) to say to fossil fuel companies "Can you pretty please lower your production?" In that case, it is clear that future generations are screwed. But if we decide to take climate action seriously, then we use all the tools in our toolkit, including dramatic emissions reduction (i.e., *phasing out* fossil fuels... not just promoting renewables), CDR, and SRM. Also, it appears that SRM is now *required* to stay under 2ºC and to avoid tipping points because emissions reduction and CDR do not change global temperatures quickly. So if an AMOC collapse is coming in 20 to 50 years, then SRM is probably needed to stop the flow of fresh water from melting Greenland soon, not 50 to 100 years from now.
Thats simply not accurate. We can limit warming to well-below 2C (~1.8C) if we get global CO2 emissions to zero by 2070 or so (e.g. the SSP1-2.6 scenario). You may well be pessimistic that we will, but thats a value judgement on our political will and technological aptitude, not a physical reality.
You are conflating physical possibility with practical reality. According to James Hansen's "Pipeline" paper, we may hit 2ºC in the 2030s and there is no practical way to avoid 2ºC in the 2030s or 2040s because we obviously don't have the political will to take serious action right now and fossil fuel emission are at a record high! You are also assuming a best-case scenario for ECS, feedbacks, etc. We are ~1.8ºC right now and you think we can stay below it by getting to Net-Zero in 2070?!? When dealing with existential risks, you must hope for the best and plan for the worst. In other words, it is not enough for you to say, "I think Hansen is wrong." You need to *prove* he is wrong and prove that your "best-case" scenario is correct. The Space Shuttle Challenger blew up because NASA asked the rocket engineers to prove that it would blow up at cold temperatures instead of asking them if they can assure that it won't blow up. We need to also make sure we are asking the right questions. http://www.huffingtonpost.com/dan-miller/the-space-shuttle-challen_b_466605.html
SSP1-2.6 is designed to have a roughly 66% chance to limit warming to below 2C, with a central estimate of around 1.8C. So yes, it’s possible we get unlucky with climate sensitivity and end up past 2C, and that would be a situation where it would make a lot of sense to consider SRM. But saying that we know we will pass 2C in the 2030 is simply not accurate. There is a very small chance across the CMIP6 ensemble (< 5%), and it’s pretty far from the central estimate.
You are quoting IPCC scenarios that have, historically, proven to be optimistic (and, again, we are around 1.8ºC right now!). For example, current forcing (not emissions) is close to the RCP8.5 scenario right now. Hansen says the IPCC predictions are wrong and gives the reasons for his hypothesis (Ice Age temperatures, current EEI, etc.). Given the existential nature of the situation, we must *assume* he is correct and act accordingly, unless you can "prove" he is wrong, which you cannot. In any case, assuming he is correct -- that the situation is more dire than the IPCC says -- will lead us to a safer world for our children if we act accordingly. We are not discussing black holes where it's fine to take the academic high ground and wait to see how things play out. We are talking about whether our children will face a climate system spiraling out of control with >2ºC warming in their lifetime and a high chance of passing irreversible tipping points.
Geoengineering just isn't something that humans have the governance capability to manage--and the reality of increasing conflict between world powers makes it unlikely we will gain it in the near future.
This is Silicon Valley hubristic insanity, a nightmare of an idea.
Pre/debunking it and explaining why it's a dangerous plan should be part of geoengineering conversations now. There is no serious response to climate change that involves monetising SO2 releases by selling them as carbon indulgences.
The general public needs to be hearing that message from their trusted sources now, before it creeps into mainstream discourse.
The risk of unintended consequences from most geoengineering 'solutions' is real and significant, which is why iron fertilisation of the oceans should be the only (or one of very few) geoengineering methods attempted. Iron fertilisation of the oceans has been shown to be safe, effective and natural so it should be trailed more seriously than it has been in the past.
There is relatively little evidence that iron fertilization would result in long-term removal of CO2. I'm personally more bullish on things like ocean alkalinity enhancement, but they are far from a silver bullet or an alternative to significant mitigation.
There is actually a lot of geological evidence to show that iron fertilisation of marine waters works and I encourage you to search on Google Scholar for the available information. The technique has its critics but geological evidence is strong that it has occurred in the past, with one research report showing an 80ppm drop in atmospheric CO2 over a few thousand years.
Have you considered that high consuming "advanced" nations have a technology fetish? While their production, consumption, and irresponsible disposal practices destroy the atmosphere and many life forms, concerned people are distracted by the ideology that technology can save us.
The real problem is to be found in social economic practices that rely on infinite growth - so much so that when girls and women freely choose to have fewer babies, thus beginning the process of population reductions in already overcrowded areas of the earth, national leaders announce a fertility crisis. Why? Because declining populations threaten corporate profit rates. Any economic system that can't adjust to a smaller population is not an economic system worthy of the name. Supporting women's rights and changing economic practices is what we need to deal with the climate crisis.
I will admit that SRM proposals have major flaws, other than surface-based albedo enhancement through mirrors, which can be used TODAY with many co-benefits to agriculture and water preservation, without toxins. Hopefully, any weather disruptions it may cause will not be worse than those already gaining traction daily. What Zeke fails to accept is that by pursuing only GHG management, and perhaps magically managing to stop emissions relatively soon (a decade or two would be amazing), we will cross tipping points anyway before then, being egged on by the continuing rise in temperatures no matter what Zeke’s toy models suggest. The moral hazard argument is so weak: we are already not reducing emissions, so why insist that we not try SRM because…that might lead to not reducing emissions? Zeke, where is your logic?
Zeke calls SRM a gamble, but he is merely pursuing one gamble, with GHG management, over another. The time for GHG management to effectively control warming is at least 50 years too late.
This seems a workable and feasible action to consider and to continue with studies and experiments with stratospheric seeding.
This fills me with inspiration, until I remember why we can't have good things ("anymore").
As an apt analogy, imho: think of fighting climate change as supporting Ukraine. Most people were for it (and still do), and the US sent a lot of support for a couple of years. Then one party threw a wrench into the works and we have the real specter of Russia rolling over the Ukrainians. A terrible outcome, and not just for Ukraine; NATO and Europe invest in more measures to address the situation.
If we maintained or improved upon the temperatures with the stratospheric chemical seeding, I offer an analogy that saving Ukraine is the same as maintaining our global temperature average (or hemispheric.. average, or whatever). Russia winning is analogous to global warming winning.
If future humans, with all the weaknesses of today's pathetic example of humans, we can expect that the required strato-seeding will fall by the wayside at some point as people kick the can down the road for a week, then a month, then skipping years. As was mentioned, this could force the future humans (our grandchildren and theirs, too) to deal with the multi-trillion dollar disaster, probably by losing permanently.
Especially: "At the same time, I’m also cognizant that not treating the symptoms of climate change through something like SRM in the hopes that more suffering would speed up mitigation is arguably morally reprehensible in its own way."
Judging by the number of people commenting, this is a very intriguing topic. My position is unchanged and in synchrony with yours; research geoengineering aggressively but deploy it with utmost caution. Our root (I think) problem is overpopulation and we must bring our numbers down by at least three quarters.
The root of our problem is burning fossil fuels, full stop. We could decarbonize our economy and manage climate change even with a large population (though global population seems to be on track to peak and decline after 2050 or so).
Consider this Zeke, we could decarbonize right now but that wouldn't stop the large forces we've already set in motion, the tens of thousands of species lost, the methane gases being released in the thawing permafrosts, the impending collapse of the AMOC, the increased heating of soils, ocean and troposphere. The changing hydrologic transport mechanisms... Decarbonization is a vital piece of the puzzle yes
But it's not the only piece. Though the demographics may suggest a net global polulation decline, the economic upraising of the third world points toward increased consumerism there with all that implies. Fossil fuels aren't the only thing we have on.our plate of challenges, nor is it even the most important. Fossil fuel use is driven by consumption. Ultimately consumption is driven by consumers. I still believe that population is the root problem, but we still eliminate fossil fuel use.
Consumption with economy–wide upstream co2-e pricing is the root of our solution…which cannot advance without the world's dominant economy on board. The fact that US financial leaders, with egg on their faces from the implosion of ESG, never speak of this is grotesque. What does society get for the $10 trillion or so of financial sector market cap? At least they could speak up for market price integrity consistent wth climate stability. Sure beats ESG.
May beat ESG (of which I'm not a huge fan- so sue me) but they won't speak up. It's just so old fashioned to look at fuddy duddy ideas like ROI unlinked from social responsibility. Co2 EOR needs to increase twentyfold at the minimum at current production rates IMO. BTW, I am not an economist nor VC nor expert in anything but voicing untutored opinions. Thank you for your commendable restraint in your reply.
Perhaps, though the thermodynamics of capturing diffuse carbon in the atmosphere or ocean are inherently challenging. Coming down from $500/ton today to $100/ton is already pretty ambitious.
My introduction to geo-engineering was via a number of science fiction novels read back in the early 1960s though they were published across a span of decades, but I remember that most of them incorporated a rather daunting learning curve for the geo-engineers with a fair bit of trial and error!
Zeke, I enjoy reading your writing regardless the topic and do respect the analyses that you have posted earlier. I agree here with your trepidation. I must admit, don't apologise for my age, 80+, but one important ingredient that our Earth lacks today--- is leadership. Humans have a lousy record of change for the greater good. I try to be optimistic for our youngest generation but it is very difficult. I can only hope that they can show us how we should live together.
Well written. True to my understanding of the state of affairs.
This is a much more reasonable take on the topic than another one I read recently, which was "Let's start SRM yesterday!"
Nice piece. For more on SRM, you can check out my substack dedicated to it: https://peteirvine.substack.com/
Amazing how humans are always tampering with things they know little about. Arrogance bordering on insanity.
Tampering with things you know little about is the first step to learning.
Just because you can - does not mean you should.
My favorite allegory of the ignorant arrogance ("arrognorance"? "ignorogance"?) of humanity is "the Sorcerer's Apprentice", from Disney's groundbreaking 1940 film "Fantasia" (https://video.disney.com/watch/sorcerer-s-apprentice-fantasia-4ea9ebc01a74ea59a5867853). Too bad there's no benevolent master sorcerer to rescue us as we circle the drain!
If you think that SRM will lead to less emissions reduction, then you are assuming to will continue to not take climate action seriously. If we continue to "choose to fail", as Kevin Anderson puts it, then we will fail. We should instead assume we will someday choose to succeed. When that day comes, SRM will be an important tool to fight the impacts of climate change and avoid tipping points. It is likely that SRM is *required* very soon in order to avoid tipping points such as an AMOC collapse, since emissions reduction and CDR will take decades to reduce warming and slow the melting of Greenland which produces the fresh water that is contributing to the slowdown of the AMOC. The costs and risks of SRM must be viewed in the context of *not* doing SRM. I believe the risks of not doing SRM greatly outweigh the risks of doing it.
My worry is if folks realize we can effectively postpone climate change for a few billion $ per year, we go down that route and screw over future generations. One thing I've come to realize working on permanent carbon removal for my day job with Stripe/Fronter is the less we need to rely on it, the better off we will be. I'm extremely skeptical of our collective willingness to spend trillions in the future to reverse climate change, vs normalizing the harms to human and natural systems in a warmer future...
Again, you are assuming that we will not take climate action seriously and we will continue (like now) to say to fossil fuel companies "Can you pretty please lower your production?" In that case, it is clear that future generations are screwed. But if we decide to take climate action seriously, then we use all the tools in our toolkit, including dramatic emissions reduction (i.e., *phasing out* fossil fuels... not just promoting renewables), CDR, and SRM. Also, it appears that SRM is now *required* to stay under 2ºC and to avoid tipping points because emissions reduction and CDR do not change global temperatures quickly. So if an AMOC collapse is coming in 20 to 50 years, then SRM is probably needed to stop the flow of fresh water from melting Greenland soon, not 50 to 100 years from now.
Thats simply not accurate. We can limit warming to well-below 2C (~1.8C) if we get global CO2 emissions to zero by 2070 or so (e.g. the SSP1-2.6 scenario). You may well be pessimistic that we will, but thats a value judgement on our political will and technological aptitude, not a physical reality.
You are conflating physical possibility with practical reality. According to James Hansen's "Pipeline" paper, we may hit 2ºC in the 2030s and there is no practical way to avoid 2ºC in the 2030s or 2040s because we obviously don't have the political will to take serious action right now and fossil fuel emission are at a record high! You are also assuming a best-case scenario for ECS, feedbacks, etc. We are ~1.8ºC right now and you think we can stay below it by getting to Net-Zero in 2070?!? When dealing with existential risks, you must hope for the best and plan for the worst. In other words, it is not enough for you to say, "I think Hansen is wrong." You need to *prove* he is wrong and prove that your "best-case" scenario is correct. The Space Shuttle Challenger blew up because NASA asked the rocket engineers to prove that it would blow up at cold temperatures instead of asking them if they can assure that it won't blow up. We need to also make sure we are asking the right questions. http://www.huffingtonpost.com/dan-miller/the-space-shuttle-challen_b_466605.html
SSP1-2.6 is designed to have a roughly 66% chance to limit warming to below 2C, with a central estimate of around 1.8C. So yes, it’s possible we get unlucky with climate sensitivity and end up past 2C, and that would be a situation where it would make a lot of sense to consider SRM. But saying that we know we will pass 2C in the 2030 is simply not accurate. There is a very small chance across the CMIP6 ensemble (< 5%), and it’s pretty far from the central estimate.
You are quoting IPCC scenarios that have, historically, proven to be optimistic (and, again, we are around 1.8ºC right now!). For example, current forcing (not emissions) is close to the RCP8.5 scenario right now. Hansen says the IPCC predictions are wrong and gives the reasons for his hypothesis (Ice Age temperatures, current EEI, etc.). Given the existential nature of the situation, we must *assume* he is correct and act accordingly, unless you can "prove" he is wrong, which you cannot. In any case, assuming he is correct -- that the situation is more dire than the IPCC says -- will lead us to a safer world for our children if we act accordingly. We are not discussing black holes where it's fine to take the academic high ground and wait to see how things play out. We are talking about whether our children will face a climate system spiraling out of control with >2ºC warming in their lifetime and a high chance of passing irreversible tipping points.
I've been assuming that we _would_ take climate action seriously soonish, but I've been wrong about that for 30 years now.
Thanks for this thoughtful piece.
The scientific uncertainties around geoengineering seem far more solvable than the geopolitical ones.
The calls for a Non-Use Agreement on Solar Geoengineering make clear the likelihood of considerable, and imo justified, resistance to the idea. Folks who want to learn more should find the open letter (https://www.solargeoeng.org/non-use-agreement/open-letter/) and briefing paper (https://www.solargeoeng.org/resources/briefing-notes/) from advocates of the agreement worth their time.
Geoengineering just isn't something that humans have the governance capability to manage--and the reality of increasing conflict between world powers makes it unlikely we will gain it in the near future.
I agree that the politics are the messy part here. There are no easy answers unfortunately, apart from rapid emissions reductions.
100% agree. Rapid emissions reductions are the only path forward.
I came across this today. https://unchartedterritories.tomaspueyo.com/p/so2-injection
This is Silicon Valley hubristic insanity, a nightmare of an idea.
Pre/debunking it and explaining why it's a dangerous plan should be part of geoengineering conversations now. There is no serious response to climate change that involves monetising SO2 releases by selling them as carbon indulgences.
The general public needs to be hearing that message from their trusted sources now, before it creeps into mainstream discourse.
The risk of unintended consequences from most geoengineering 'solutions' is real and significant, which is why iron fertilisation of the oceans should be the only (or one of very few) geoengineering methods attempted. Iron fertilisation of the oceans has been shown to be safe, effective and natural so it should be trailed more seriously than it has been in the past.
There is relatively little evidence that iron fertilization would result in long-term removal of CO2. I'm personally more bullish on things like ocean alkalinity enhancement, but they are far from a silver bullet or an alternative to significant mitigation.
There is actually a lot of geological evidence to show that iron fertilisation of marine waters works and I encourage you to search on Google Scholar for the available information. The technique has its critics but geological evidence is strong that it has occurred in the past, with one research report showing an 80ppm drop in atmospheric CO2 over a few thousand years.
Have you considered that high consuming "advanced" nations have a technology fetish? While their production, consumption, and irresponsible disposal practices destroy the atmosphere and many life forms, concerned people are distracted by the ideology that technology can save us.
The real problem is to be found in social economic practices that rely on infinite growth - so much so that when girls and women freely choose to have fewer babies, thus beginning the process of population reductions in already overcrowded areas of the earth, national leaders announce a fertility crisis. Why? Because declining populations threaten corporate profit rates. Any economic system that can't adjust to a smaller population is not an economic system worthy of the name. Supporting women's rights and changing economic practices is what we need to deal with the climate crisis.
I will admit that SRM proposals have major flaws, other than surface-based albedo enhancement through mirrors, which can be used TODAY with many co-benefits to agriculture and water preservation, without toxins. Hopefully, any weather disruptions it may cause will not be worse than those already gaining traction daily. What Zeke fails to accept is that by pursuing only GHG management, and perhaps magically managing to stop emissions relatively soon (a decade or two would be amazing), we will cross tipping points anyway before then, being egged on by the continuing rise in temperatures no matter what Zeke’s toy models suggest. The moral hazard argument is so weak: we are already not reducing emissions, so why insist that we not try SRM because…that might lead to not reducing emissions? Zeke, where is your logic?
Zeke calls SRM a gamble, but he is merely pursuing one gamble, with GHG management, over another. The time for GHG management to effectively control warming is at least 50 years too late.
This seems a workable and feasible action to consider and to continue with studies and experiments with stratospheric seeding.
This fills me with inspiration, until I remember why we can't have good things ("anymore").
As an apt analogy, imho: think of fighting climate change as supporting Ukraine. Most people were for it (and still do), and the US sent a lot of support for a couple of years. Then one party threw a wrench into the works and we have the real specter of Russia rolling over the Ukrainians. A terrible outcome, and not just for Ukraine; NATO and Europe invest in more measures to address the situation.
If we maintained or improved upon the temperatures with the stratospheric chemical seeding, I offer an analogy that saving Ukraine is the same as maintaining our global temperature average (or hemispheric.. average, or whatever). Russia winning is analogous to global warming winning.
If future humans, with all the weaknesses of today's pathetic example of humans, we can expect that the required strato-seeding will fall by the wayside at some point as people kick the can down the road for a week, then a month, then skipping years. As was mentioned, this could force the future humans (our grandchildren and theirs, too) to deal with the multi-trillion dollar disaster, probably by losing permanently.
Well said.
Especially: "At the same time, I’m also cognizant that not treating the symptoms of climate change through something like SRM in the hopes that more suffering would speed up mitigation is arguably morally reprehensible in its own way."
Judging by the number of people commenting, this is a very intriguing topic. My position is unchanged and in synchrony with yours; research geoengineering aggressively but deploy it with utmost caution. Our root (I think) problem is overpopulation and we must bring our numbers down by at least three quarters.
The root of our problem is burning fossil fuels, full stop. We could decarbonize our economy and manage climate change even with a large population (though global population seems to be on track to peak and decline after 2050 or so).
Consider this Zeke, we could decarbonize right now but that wouldn't stop the large forces we've already set in motion, the tens of thousands of species lost, the methane gases being released in the thawing permafrosts, the impending collapse of the AMOC, the increased heating of soils, ocean and troposphere. The changing hydrologic transport mechanisms... Decarbonization is a vital piece of the puzzle yes
But it's not the only piece. Though the demographics may suggest a net global polulation decline, the economic upraising of the third world points toward increased consumerism there with all that implies. Fossil fuels aren't the only thing we have on.our plate of challenges, nor is it even the most important. Fossil fuel use is driven by consumption. Ultimately consumption is driven by consumers. I still believe that population is the root problem, but we still eliminate fossil fuel use.
Consumption with economy–wide upstream co2-e pricing is the root of our solution…which cannot advance without the world's dominant economy on board. The fact that US financial leaders, with egg on their faces from the implosion of ESG, never speak of this is grotesque. What does society get for the $10 trillion or so of financial sector market cap? At least they could speak up for market price integrity consistent wth climate stability. Sure beats ESG.
May beat ESG (of which I'm not a huge fan- so sue me) but they won't speak up. It's just so old fashioned to look at fuddy duddy ideas like ROI unlinked from social responsibility. Co2 EOR needs to increase twentyfold at the minimum at current production rates IMO. BTW, I am not an economist nor VC nor expert in anything but voicing untutored opinions. Thank you for your commendable restraint in your reply.
Great summary of a complicated issue that need an open discussion.
Surely the technology to remove CO2 will improve and cost will come down in the coming decades? So the debt may not be as large as you think...
Perhaps, though the thermodynamics of capturing diffuse carbon in the atmosphere or ocean are inherently challenging. Coming down from $500/ton today to $100/ton is already pretty ambitious.
All the more reason for a stop-gap solution while we figure it out, no? Those in the decarbonization space won't walk away just because the *worst* consequences could be avoided? They'd still believe in the value of what they're doing, regardless of what the geoengineers are doing. Did you read this yet? https://open.substack.com/pub/unchartedterritories/p/so2-injection?utm_source=share&utm_medium=android&r=9fely
My introduction to geo-engineering was via a number of science fiction novels read back in the early 1960s though they were published across a span of decades, but I remember that most of them incorporated a rather daunting learning curve for the geo-engineers with a fair bit of trial and error!