Unfortunately this article reminds me of an Arabian fable: the geoengineering camel wants to get its nose into the climate mitigation sheikh's tent!
I think a pilot geoengineering project is a bad idea. However, I do support research on geoengineering, including small-scale field testing, but well short of any deployment.
The problem is that a lot of geoengineering discussion, including this article, has a simplistic global-average temperature framing. The impression is that there is a single knob, global-average temperature, that can simply be "dialed back" to mitigate the impacts of global warming. With the exception of perhaps steric sea level rise, the harm due to GHG-driven warming is local (heatwaves, intense rainfall, ...). To the extent that tropospheric sulfate aerosols compensate this harm, it happens locally. Stratospheric sulfate aerosols will have a different spatial cooling pattern. It is therefore simplistic to suggest that the global harm due to GHG-driven warming is being compensated by global benefits of tropospheric aerosol-driven cooling or that sulfates in the stratosphere can provide the same cooling benefits as sulfates in the troposphere.
The crucial fact is that carbon dioxide is well-mixed and long-lived. Sulfur dioxide is not well-mixed and short-lived in the troposphere. Their opposing radiative impacts cannot be captured by their contribution to a single global-average number. To truly negate the climate impacts of carbon dioxide increases at the source, we need carbon dioxide removal (CDR). However, CDR is an extremely unproven approach, and possibly very expensive. In contrast, the radiative impacts of the relatively inexpensive SAI are generally known, thanks to the analog of natural volcanic eruptions, but to compute its climate impacts we need to rely on imperfect climate models.
The suggestion that we can start a modest geoengineering deployment and then we can measure its efficacy is misleading. We may be able to measure the radiative impacts of modest SAI over a decade to so, but precisely attributing its local dynamical climate impact will take several decades (beyond the putative net-zero horizon) and better climate models (with smaller errors) than we currently have, because of irreducible internal variability and model inadequacies. The slow ramp up of SAI means a very low signal-to-noise ratio, which won't help in detection and attribution of its impacts.
Another argument frequently trotted out by geoengineers is that we need geoengineering to avoid imminent tipping points. (Interestingly, most proponents of tipping point-related urgency are not supporters of geoengineering; they want radical emission reduction!) Tipping points, to the extent that they exist close to the present climate and their imminence can be predicted with any precision (both of which are iffy suppositions based on imperfect, often simplified, models), are not triggered by global-average phenomena. They are triggered by local processes. There is no precise global-average temperature threshold to trigger them because global climate models differ in their absolute global average temperature estimates by several degrees, even if they are in closer agreement on the temperature change (delta) associated with GHG warming. Being nonlinear phenomena, tipping points thresholds will depend on absolute temperatures, not deltas.
To reiterate, the responsible thing to do is to stick to modestly funded research in geoengineering (with some field tests), like we do for fundamental science, and not let faux urgency scare us towards deployment.
Thats a reasonable critique, and I should have been clearer in this piece that we are not assuming a 1 for 1 regional replacement of aerosol cooling. Somewhere with highly localized effects like India might see only half as much cooling in a world where global average forcing is held constant but aerosols are in the stratosphere rather than the troposphere (not to mention precipitation effects!). But I still think that it serves as a useful heuristic for limiting the scale of deployment in a world where policymakers decide to pursue climate interventions, even if the effects would not be identical.
The goal of the piece was not to advocate deployment, but rather start a discussion of how to narrowly limit any future deployment.
I would argue that any future SAI deployment , if it should ever come to that, would not be narrow ("break glass in case of emergency"). By narrowly limiting deployment, we wouldn't be able to attribute any short-term climate changes unambiguously to SAI due to irreducible observational uncertainty and model uncertainty. Thus, we would be expending resources without any accountability. We would be bearing the operational costs of SAI, plus the political costs, without clearly attributable benefits.
Incremental deployment without attributability could also be a legal nightmare. Like the National Vaccine Injury Compensation Program (future in doubt?), any global climate intervention would perhaps need an International Regional Climate Harm Compensation Fund for political (and equity) reasons. Only a glass-breaking emergency would likely unite the nations to support such an effort. (Of course, the research on geoengineering would need to be carried out before we get to the glass-breaking point.)
(Your piece may not be explicitly advocating deployment, but most opponents of geoengineering may not view it that way, because it is setting the stage for deployment.)
Your comments are very much appreciated, and force one to ask: if a full-scale deployment of SAI is unwise, and a small scale deployment as suggested will render any assessment of its impact a mystery, then where does that leave us? Other fast cooling proposals, such as surface-based reflectors, MCB, high-albedo crops, and others, are much more tuneable than SAI and, particularly considering surface-based reflectors, offer the additional benefit when being introduced on a small scale of acting as purely localized climate adaptation solutions offering valuable heat relief or important protection for canals and reservoirs suffering from water evaporation that global-only proposals like SAI cannot offer.
Very small-scale cooling solutions do work: AC at homes, covering up canals to reduce evaporation etc. But at regional scales, the benefits local radiative cooling could be counteracted by warm air flowing in from neighboring regions which are still warming, because the atmosphere is not a purely local thermodynamic system. Regional albedo change deployments can also change air circulation due to the regional cooling which could have undesirable effects in neighboring regions that could be blamed on that specific albedo change deployment.
Climate is a complex noisy system with many nonlocal and nonlinear interactions. So one needs to consider these interactions and feedbacks when tweaking it. Models can help assess the impacts but they are imperfect. So actual deployment with measurable (signal > noise) impacts may be the only (and risky) way to assess the efficacy of the tweaking.
First, in the 6th paragraph you say troposphere instead of stratosphere.
More seriously, the complacency argument against intervention is becoming weaker and weaker. The cost of solar and wind is becoming the least expensive source of electricity and becoming the leading investment. The idea that the world will go back to coal seems illogical as it, in the US costs about three times as much as wind and solar and that factor is growing as the cost of solar and wind drop below eve natural gas. What we need to do is to help encourage this transition. California is doing it, for example, by building transmission lines from locations where sunlight harvesting with solar can be very cost effective to the main transmission lines and this is attracting all sorts of private sector investment in solar (in Google Earth, check just to the west of Antelope Valley, California to see where a few billion for a transmission line has led to of order 20 times as much investment in building solar). As Sandy MacDonald made clear in his oped in The Hill (see https://thehill.com/opinion/energy-environment/5114155-us-energy-revolution-supergrid/), what would really help our energy conversion is a high-voltage direct current national network (and a book he is writing urges that for every continent). The profit motive can convincingly overcome regression to fossil fuels if we help it in the right way, and if this is done, then the real moral hazard of geoengineering is not doing it to save all the lives and damage from extreme events (drenching rains and intolerable heat waves) and the commitments to a much higher sea level and thawing of permafrost and all the carbon dioxide and or methane that will be reduced. I would really urge your reconsideration of climate intervention--sure it is not a solution in itself and I am all for more aggressive mitigation and helping that along, but I think the metaphor of a tourniquet is better than a bandaid (even a slightly flawed tourniquet would be better than bleeding to death).
Good catch on paragraph six; fixed that. I agree that clean energy is becoming cheaper, but we are also picking the low hanging fruits of decarbonization today. Long distance transport, industrial heat, buildings, etc. will all be harder and more expensive than grids.
With abundant cheap solar, wind, geothermal and other renewable energy, this will make a lot possible, like making hydrogen or similar liquid fuel for long distance transport, industrial heat, heating buildings where heat pumps aren't viable, etc. The grid will also enable access to storage of all types, batteries, caverns, pumped storage, wherever it exists and is least expensive--and the grid and storage can allow whatever nuclear there is to run at steady state, which is most efficient. And making hydrogen, desalinating seawater, and other uses can be done at times when there is overabundance of energy and/or power is least expensive. Biden's plan was to green the existing grid--building a high-voltage direct current national network starting with some key links is what is needed to green the whole US economy and we need to get going on it. And fixing the grid, as China and Europe are already starting to do, is essential if the US is to be competitive in the 21st century world--there are many non-climate change related reasons to do it now (it would be more secure, more reliable as well as supply lower cost electricity for the country)--national decarbonization would be a side benefit were there a comprehensive analysis of how to best ensure the international role of the US in the 21st century.
"And fixing the grid, as China and Europe are already starting to do, is essential if the US is to be competitive...."
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Sadly, the costs of grid upgrades in the US are increasing due to multiple factors:
- Tariffs have made materials significantly more expensive, at least in the near term.
- Stephen "Goebbels reborn" Miller's masked Schutzstaffel are rounding up much of the people who do real work in this country.
- New power pylons in many areas have to be spec'd to handle higher winds, like the towers taken down by the derecho that passed through Houston a couple of years ago. AIUI, they should be rated to handle 80mph winds instead of 60mph. Some of that may be addressed by more clever design that is frugal with both material and labor.
- [Don't forget the lawyers!] Extending the grid today encounters more legal expense for crossing private property that wasn't as much of a problem sixty years ago.
Hi--Agreed. That is why the proposal of Sandy MacDonald explained in The Hill calls for under grounding the HVDC lines on already existing, essentially public rights of way, so along railroad lines (for some, US Government has control, for others it is railroads), interstate highways (states actually have control), rivers, and so on in order to avoid the decade or two that it takes, if ever, to get aboveground lines, especially over private property. He also proposes AC/DC converter stations in each state to ensure all along the way can benefit. Also, by under grounding the hope is to make the lines less vulnerable to severe weather, to solar storms, and to the electromagnetic pulse from nuclear explosions in space or the upper atmosphere, etc. On tariffs, that is really why what is proposed to implement the network are public-private partnerships and hopefully the government would then waive the tariffs (assuming they are not just declared illegal) as is now proposed for coffee beans, etc.
You prompted me to check on the SOO Green project, which I haven't looked into for years. It appears they're still going through local approval for certain stretches. :(
I've been following Peter Sinclair's coverage of the introduction of solar arrays or wind turbines on leased farmland (no eminent domain), and county and town councils being mobbed by ginned up fanatics with all sorts of scary stories ranging from electrical dangers to lowering property prices. Among his many pieces he compiled a comparison of a county which rejected wind turbines to a nearby one that accepted them.
A Tale of Two Counties - A Lesson About Wind Energy
Your view seems to mistakenly consider the energy transition as sufficient to contain climate change, while not admitting of any need to drastically reduce energy consumption.
"We" (ie. taxpayers) should not be encouraging one form of energy over another. If we stop government interventions such as subsidies, priority access to grids by renewables and getting taxpayers to fund transmission networks and backup systems for renewables, we might get a true indication of what is the cheapest way to generate electricity and reliably deliver it 24/7 to customers and industries.
The cheapest electrical generation continues to be simply building an additional boiler module in an existing coal fired power station because 80% to 90% of the equipment, people, technology, transmission circuitry and services are already there. I wish this wasn't true, but it is.
Understandably, we don't want coal, so we rig the system against coal and keep telling lies about the true all-up cost (including subsidies etc) of delivering reliable electricity to customers from intermittent renewables that are usually located in remote places so that rural communities bear all the social costs of having the toxic renewable solar panels, wind turbines and power transmission lines across their land. We need to tell the truth that renewables cause energy costs to rise signficantly and destabilise the grids and then let the community decide what is best. I hope communities are mature enough to make the best choice rather than have a "dodgy strategy" imposed on them.
I will believe that renewables are the best strategy when I see solar panels and wind turbines built without subsidies and located in wealthy suburbs rather than in poorer fly-over regional areas. Once renewables reach 25% to 30% of the electricity supply, building more nuclear and operating cleaner coal plants longer while the nukes are being built is a reasonable transition strategy.
"a few billion for a transmission line has led to of order 20 times as much investment in building solar"
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The success of west Texas wind and solar farms owes a lot to major transmission lines constructed beforehand. Additionally, ERCOT's model has encouraged the construction of private arbitrage grid battery storage, which has spared us from rotating blackouts in the increasingly hot summers.
Thanks for this post! I think this is an important discussion to have. In the last post on my own blog I also highlighted stratospheric aerosol injections and how they might interact with something like nuclear winter, might be worth also checking out if the topic is of interest: https://existentialcrunch.substack.com/p/manipulating-the-global-thermostat
The analysis presented makes sense in the abstract, but in the real world the risks are enormous and probably uncontrollable. The implicit assumption here is that rational, ethical government actors -- who understand and respect science and the rule of law, and who prioritize global well-being over narrowly perceived self-interest -- will collectively control decision-making about deployment of, and limits on, SAI. Unfortunately, based on history and the daily news, we have every reason to think that will not be the case. Small-scale rogue actors are one legitimate worry; but powerful countries with rogue leaders are a larger, more dangerous, and more intractable concern.
My understanding is that the SOO Green line has all the approvals and materials, etc. to get started. What it lacks is high level Administration approval as it is basically carrying wind power to the grid. The delay is very unfortunate and that the reason for it is political and not technical is disgraceful.
I think the most compelling arguments for it are 1) just how long elevated temperatures will be with us. If we wind up at 2.5 degrees above pre industrial levels, it will be hundreds of years until it cools back down. If we all agree that would be a bad outcome, geoengineering will be able to keep the planet cooler (until we can remove the CO2 as you say). 2) tipping points. If we can cool the planet and stop the ice caps melting, that would also be very beneficial.
Both of these outweigh any moral hazard arguments IMO, which I just don't find that convincing given the trends in solar + storage. By the time we deploy geoengineering, the tools we have to cut emissions will be well on their way to doing so (if not quite as fast as we would e).
We're on the same curve where money available to fix things is in competition with money needed to respond to disasters, or money lost to things like housing market collapses and their resulting decline in property tax revenue. (Conversely, had we started working on this this a couple of decades ago, it would have been much cheaper and easier. Instead we sacrificed it all on the altar of the fossil fuel industries' "shareholder value" god.)
I am intrigued by the proposal to conduct limited geoengineering for a few reasons. One that I haven't heard yet is the opportunity to see whether the tests would encourage continued high rates of CO2 uptake by the ocean. Currently, the ocean absorbs CO2 at rates that are directly proportional to atmospheric levels -- with a high r-squared term -- so one should expect to see this continue even as we reach "peak anthropogenic CO2 emissions", which could be any year now.
(By the way, the IEA has pointed out that the reason that we have been "bending the CO2 emissions curve" over the past 10+ years is that we are learning to reduce the cost of modular, low-carbon technologies, like heat pumps, fuel cells and photovoltaics... so that when built in sufficiently large numbers, they become economically-preferable to older, fossil energy technologies that were dependent on economies of scale.)
Another thought concerns the extent to which geolocation and timing matter. For example, would stratospheric sulfur injection in the northern hemisphere polar region, during spring and summer, help preserve polar ice (including Greenland's glaciers, which also suffer from seasonal feedback loops)?
A few years of solar geoengineering seems like an opportunity to briefly limit warming, develop a greater understanding of ocean uptake (including limitations of the biological carbon pump) and perhaps see whether we can influence the loss of polar ice.
Limiting cooling from geoengineering to avoid weather event effects is a necessity; that means it cannot have a major impact on warming, but only a smaller one. I believe that having ships (and planes?) spray saltwater or other chemicals to raise small, local cloud reflectivity can be helpful and not too expensive while avoiding climatilogical horrors. Do you agree?
I have wondered if self-powered facilities at sea—especially near the equator—could produce steam plumes (aka "clouds") with relatively high reflectivity.
This is an important question - thanks for addressing it in public forums. If we go ahead with it, who’s “we?” Should the US do it alone? China? Russia? The UN (imagine the howls against “world government”)? How do we keep track of how much sulfur is injected? The same questions probably apply more or less to any other mitigation strategy.
I agree with this statement: "We are already geoengineering the planet today, but badly."
But when I read that I thought it was to point out that the large scale emissions of GHG is the most significant and dangerous geoengineering experiment that we are doing today and committed to do for decades more. Like aerosols, GHG emissions are a by-product of energy use.
The important question from a moral (and legal) perspective is how long we can really call GHG 'unintentional' and 'byproduct'. We have known for a long time now what the impacts and risks are related to continued GHG emissions. We have technologies to mitigate, reduce and even remove emissions. The main reason we are not doing that is the costs. We need to get tougher on atmosferic pollution. Unfortunately, the opposite seems to be happening. I agree with you, band-aids are not the solution and carry a high 'slippery slope' risk.
Are you really questioning the fact that GHG emissions from fossil burning are unintentional? Calling that an experiment requires a failure to understand what the word means. You're right that we have known far too long now what the impact of GHGs from fossil burning are, but we cannot simply stop burning fossils overnight. And your "technologies" for GHG mitigation, reduction and removal, are likely the ones (CCS, BECCS, DAC, etc.) we all know are unscalable and fraught with other problems as well, unless you have other ideas in mind, such as a complete re-do of our social and economic goals to end our growth lust and start behaving like we live on a finite planet.
GHG emissions from fossil fuel emissions were definitely unintentional when we started using them. Or better worded: the impacts of these emissions were not widely known and therefore unintentional.
However, we have known now for at least 30 or 40 years (governments, companies). So it is justified to ask the question if we can still call it 'unintentional'.
Not sure what you mean by "your technologies"? The are not 'mine'. But they are critical technologies if we want to stop fossil fuels causing climate change. Just like solar, wind, batteries, nuclear are technologies that are needed to reduce fossil fuel demand.
Abatement technologies do exist and could be scaled up much faster if we really do not like 'experimenting' with our climate.
Your "better worded" addition is right. Emissions are STILL unintentional when we burn fossils. I understand that you are not intending to say that we literally are trying to emit GHGs when we cook or drive or any of the other ways we use fossil energy. And I understand that you do not literally mean that our use of fossils for fuel is an experiment. I just think that it is not meaningful to say such a thing just because we are now well aware of what is happening. We as individuals literally have no choice of what fuel to use in nearly all of our occasions of fossil burning for energy. But I am surprised that you are okay with that usage but then you call me out for saying “your” technologies, which is also clearly not meant to be taken literally.
No, they obviously are not your technologies. Whether they are "critical" or not depends on who you believe. The IPCC calls virtually nonexistent strategies like BECCS and DAC "required" and "unavoidable" despite the fact that it seems to be the scientific consensus that these strategies are simply pipedreams when it comes to scaling them to the vastness envisioned by the IPCC authors. So-called "roadmaps," whether they are done by the IPCC, IEA or Lawrence Livermore are better described as wish lists, as feasibility studies for their global implementation haven't really been carried out.
Talking about these solutions (or like Zeke's claim that we can pull together and stay below 2C) as though they are feasible is great if you want to succeed on a political level, or to be awarded funding for projects, but when it comes to reality? Not so much.
Why do you write, "The world can still come together and rapidly reduce emissions to limit warming to well-below 2C this century." Is there some science to show that this is possible in practical terms. The rate of reduction necessary could/would collapse economies and so would rapidly be stopped, in favour of growth (unfortunately). Is there a way of rapidly reducing emissions without collapsing economies?
No, its just complete hopium. We already did 1.5 and will be doing 2 late next decade. Short of a revolution to overthrow the richest 10% who produce 50% of the emissions and whose wealth is utterly tied up in assumptions of future economic growth.
Recently I have been reading about the agricultural aspect of climate change, and have learned that that contributes about 30% of the total effect (fossil fuel use is the other 70%). Every acre of agricultural use means one less acre of trees. Trees are a great (the BEST ?) way to remove CO2 from the air. About a quarter of the food (worldwide) is thrown away. Not throwing food away (feeding excess food to hogs, for instance) would allow a huge extra withdrawing of CO2 annually, via the trees that could be restored. A bigger factor in agriculture is the use of ruminants (cattle, sheep, etc). Ruminants use half of the agricultural land world wide. Cutting back significantly on the use of ruminants would free up MANY more acres for trees to annually remove CO2. Would you consider writing some articles on this aspect of climate change? (I'm new to The Climate Brink and don't know if you have already covered this area.)
There is a lot of research on this subject. Certainly, we are wasting far too many resources on raising livestock. Eating animals given our current situation isn't workable anymore on such a scale, especially considering the increasing living standards of many of the world's poor are leading them to be new meat eaters. But when it comes to trees, what is most helpful is protecting existing forests from being levelled (for example in order to plant soya or raise livestock) and secondly, to end grazing on former forest land and helping it to rewild. What is troublesome is the idea to plant monocultures of trees which then don't promote an increase in biodiversity, particularly in areas that had not been forests. Many projects like this fail to lead to a lasting forest and often result in trees that grow for a while and then whither. Demands on irrigation for such man-made forests is also a huge problem.
I'd amend that to saying that >healthy< trees are the best way to remove CO2, since those stressed trees burned in massive crown wildfires* are a good way to >add< CO2. ☹️ We're even losing sequoias, which in the past were considered extremely fire-resilient.
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*Watch out for doubt-slingers who point to the larger >area< of grassland, underbrush and agriculture fires in previous centuries. The combustion volume of these big wildfires is much, much higher than a grassland fire for the same acreage.
If we're talking about "geoengineering", why limit the discussion to atmospheric sulfur injection and not consider alternatives with less downsides such as ocean photosynthesis?
Zeke, please do explain just how you think we can "come together and rapidly reduce emissions to limit warming to well-below 2C this century" when considering that the EEI has been growing at about 0.08W per m2 in the past 2 decades, leading to 0.1°C additional locked-in warming per year. We have 25 years until 2050, so if historical trends continue, we would have an additional 2.5°C locked in, IN ADDITION to the 1.7°C locked in by the current 1.4W per m2 of EEI. So locked-in warming by 2050 would be 4.2°C over a century scale, but over 10-20 years we have about half, so about 2°C more: 1.5°C +2°C =3.5°C.
Unfortunately this article reminds me of an Arabian fable: the geoengineering camel wants to get its nose into the climate mitigation sheikh's tent!
I think a pilot geoengineering project is a bad idea. However, I do support research on geoengineering, including small-scale field testing, but well short of any deployment.
The problem is that a lot of geoengineering discussion, including this article, has a simplistic global-average temperature framing. The impression is that there is a single knob, global-average temperature, that can simply be "dialed back" to mitigate the impacts of global warming. With the exception of perhaps steric sea level rise, the harm due to GHG-driven warming is local (heatwaves, intense rainfall, ...). To the extent that tropospheric sulfate aerosols compensate this harm, it happens locally. Stratospheric sulfate aerosols will have a different spatial cooling pattern. It is therefore simplistic to suggest that the global harm due to GHG-driven warming is being compensated by global benefits of tropospheric aerosol-driven cooling or that sulfates in the stratosphere can provide the same cooling benefits as sulfates in the troposphere.
The crucial fact is that carbon dioxide is well-mixed and long-lived. Sulfur dioxide is not well-mixed and short-lived in the troposphere. Their opposing radiative impacts cannot be captured by their contribution to a single global-average number. To truly negate the climate impacts of carbon dioxide increases at the source, we need carbon dioxide removal (CDR). However, CDR is an extremely unproven approach, and possibly very expensive. In contrast, the radiative impacts of the relatively inexpensive SAI are generally known, thanks to the analog of natural volcanic eruptions, but to compute its climate impacts we need to rely on imperfect climate models.
The suggestion that we can start a modest geoengineering deployment and then we can measure its efficacy is misleading. We may be able to measure the radiative impacts of modest SAI over a decade to so, but precisely attributing its local dynamical climate impact will take several decades (beyond the putative net-zero horizon) and better climate models (with smaller errors) than we currently have, because of irreducible internal variability and model inadequacies. The slow ramp up of SAI means a very low signal-to-noise ratio, which won't help in detection and attribution of its impacts.
Another argument frequently trotted out by geoengineers is that we need geoengineering to avoid imminent tipping points. (Interestingly, most proponents of tipping point-related urgency are not supporters of geoengineering; they want radical emission reduction!) Tipping points, to the extent that they exist close to the present climate and their imminence can be predicted with any precision (both of which are iffy suppositions based on imperfect, often simplified, models), are not triggered by global-average phenomena. They are triggered by local processes. There is no precise global-average temperature threshold to trigger them because global climate models differ in their absolute global average temperature estimates by several degrees, even if they are in closer agreement on the temperature change (delta) associated with GHG warming. Being nonlinear phenomena, tipping points thresholds will depend on absolute temperatures, not deltas.
To reiterate, the responsible thing to do is to stick to modestly funded research in geoengineering (with some field tests), like we do for fundamental science, and not let faux urgency scare us towards deployment.
Thats a reasonable critique, and I should have been clearer in this piece that we are not assuming a 1 for 1 regional replacement of aerosol cooling. Somewhere with highly localized effects like India might see only half as much cooling in a world where global average forcing is held constant but aerosols are in the stratosphere rather than the troposphere (not to mention precipitation effects!). But I still think that it serves as a useful heuristic for limiting the scale of deployment in a world where policymakers decide to pursue climate interventions, even if the effects would not be identical.
The goal of the piece was not to advocate deployment, but rather start a discussion of how to narrowly limit any future deployment.
I would argue that any future SAI deployment , if it should ever come to that, would not be narrow ("break glass in case of emergency"). By narrowly limiting deployment, we wouldn't be able to attribute any short-term climate changes unambiguously to SAI due to irreducible observational uncertainty and model uncertainty. Thus, we would be expending resources without any accountability. We would be bearing the operational costs of SAI, plus the political costs, without clearly attributable benefits.
Incremental deployment without attributability could also be a legal nightmare. Like the National Vaccine Injury Compensation Program (future in doubt?), any global climate intervention would perhaps need an International Regional Climate Harm Compensation Fund for political (and equity) reasons. Only a glass-breaking emergency would likely unite the nations to support such an effort. (Of course, the research on geoengineering would need to be carried out before we get to the glass-breaking point.)
(Your piece may not be explicitly advocating deployment, but most opponents of geoengineering may not view it that way, because it is setting the stage for deployment.)
Your comments are very much appreciated, and force one to ask: if a full-scale deployment of SAI is unwise, and a small scale deployment as suggested will render any assessment of its impact a mystery, then where does that leave us? Other fast cooling proposals, such as surface-based reflectors, MCB, high-albedo crops, and others, are much more tuneable than SAI and, particularly considering surface-based reflectors, offer the additional benefit when being introduced on a small scale of acting as purely localized climate adaptation solutions offering valuable heat relief or important protection for canals and reservoirs suffering from water evaporation that global-only proposals like SAI cannot offer.
Very small-scale cooling solutions do work: AC at homes, covering up canals to reduce evaporation etc. But at regional scales, the benefits local radiative cooling could be counteracted by warm air flowing in from neighboring regions which are still warming, because the atmosphere is not a purely local thermodynamic system. Regional albedo change deployments can also change air circulation due to the regional cooling which could have undesirable effects in neighboring regions that could be blamed on that specific albedo change deployment.
Climate is a complex noisy system with many nonlocal and nonlinear interactions. So one needs to consider these interactions and feedbacks when tweaking it. Models can help assess the impacts but they are imperfect. So actual deployment with measurable (signal > noise) impacts may be the only (and risky) way to assess the efficacy of the tweaking.
First, in the 6th paragraph you say troposphere instead of stratosphere.
More seriously, the complacency argument against intervention is becoming weaker and weaker. The cost of solar and wind is becoming the least expensive source of electricity and becoming the leading investment. The idea that the world will go back to coal seems illogical as it, in the US costs about three times as much as wind and solar and that factor is growing as the cost of solar and wind drop below eve natural gas. What we need to do is to help encourage this transition. California is doing it, for example, by building transmission lines from locations where sunlight harvesting with solar can be very cost effective to the main transmission lines and this is attracting all sorts of private sector investment in solar (in Google Earth, check just to the west of Antelope Valley, California to see where a few billion for a transmission line has led to of order 20 times as much investment in building solar). As Sandy MacDonald made clear in his oped in The Hill (see https://thehill.com/opinion/energy-environment/5114155-us-energy-revolution-supergrid/), what would really help our energy conversion is a high-voltage direct current national network (and a book he is writing urges that for every continent). The profit motive can convincingly overcome regression to fossil fuels if we help it in the right way, and if this is done, then the real moral hazard of geoengineering is not doing it to save all the lives and damage from extreme events (drenching rains and intolerable heat waves) and the commitments to a much higher sea level and thawing of permafrost and all the carbon dioxide and or methane that will be reduced. I would really urge your reconsideration of climate intervention--sure it is not a solution in itself and I am all for more aggressive mitigation and helping that along, but I think the metaphor of a tourniquet is better than a bandaid (even a slightly flawed tourniquet would be better than bleeding to death).
Good catch on paragraph six; fixed that. I agree that clean energy is becoming cheaper, but we are also picking the low hanging fruits of decarbonization today. Long distance transport, industrial heat, buildings, etc. will all be harder and more expensive than grids.
With abundant cheap solar, wind, geothermal and other renewable energy, this will make a lot possible, like making hydrogen or similar liquid fuel for long distance transport, industrial heat, heating buildings where heat pumps aren't viable, etc. The grid will also enable access to storage of all types, batteries, caverns, pumped storage, wherever it exists and is least expensive--and the grid and storage can allow whatever nuclear there is to run at steady state, which is most efficient. And making hydrogen, desalinating seawater, and other uses can be done at times when there is overabundance of energy and/or power is least expensive. Biden's plan was to green the existing grid--building a high-voltage direct current national network starting with some key links is what is needed to green the whole US economy and we need to get going on it. And fixing the grid, as China and Europe are already starting to do, is essential if the US is to be competitive in the 21st century world--there are many non-climate change related reasons to do it now (it would be more secure, more reliable as well as supply lower cost electricity for the country)--national decarbonization would be a side benefit were there a comprehensive analysis of how to best ensure the international role of the US in the 21st century.
"And fixing the grid, as China and Europe are already starting to do, is essential if the US is to be competitive...."
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Sadly, the costs of grid upgrades in the US are increasing due to multiple factors:
- Tariffs have made materials significantly more expensive, at least in the near term.
- Stephen "Goebbels reborn" Miller's masked Schutzstaffel are rounding up much of the people who do real work in this country.
- New power pylons in many areas have to be spec'd to handle higher winds, like the towers taken down by the derecho that passed through Houston a couple of years ago. AIUI, they should be rated to handle 80mph winds instead of 60mph. Some of that may be addressed by more clever design that is frugal with both material and labor.
- [Don't forget the lawyers!] Extending the grid today encounters more legal expense for crossing private property that wasn't as much of a problem sixty years ago.
Hi--Agreed. That is why the proposal of Sandy MacDonald explained in The Hill calls for under grounding the HVDC lines on already existing, essentially public rights of way, so along railroad lines (for some, US Government has control, for others it is railroads), interstate highways (states actually have control), rivers, and so on in order to avoid the decade or two that it takes, if ever, to get aboveground lines, especially over private property. He also proposes AC/DC converter stations in each state to ensure all along the way can benefit. Also, by under grounding the hope is to make the lines less vulnerable to severe weather, to solar storms, and to the electromagnetic pulse from nuclear explosions in space or the upper atmosphere, etc. On tariffs, that is really why what is proposed to implement the network are public-private partnerships and hopefully the government would then waive the tariffs (assuming they are not just declared illegal) as is now proposed for coffee beans, etc.
You prompted me to check on the SOO Green project, which I haven't looked into for years. It appears they're still going through local approval for certain stretches. :(
https://www.wri.org/snapshots/community-benefits-snapshots-soo-green-transmission-line-community-engagement
I've been following Peter Sinclair's coverage of the introduction of solar arrays or wind turbines on leased farmland (no eminent domain), and county and town councils being mobbed by ginned up fanatics with all sorts of scary stories ranging from electrical dangers to lowering property prices. Among his many pieces he compiled a comparison of a county which rejected wind turbines to a nearby one that accepted them.
A Tale of Two Counties - A Lesson About Wind Energy
https://www.youtube.com/watch?v=QX-QN2i6CzY
Your view seems to mistakenly consider the energy transition as sufficient to contain climate change, while not admitting of any need to drastically reduce energy consumption.
"We" (ie. taxpayers) should not be encouraging one form of energy over another. If we stop government interventions such as subsidies, priority access to grids by renewables and getting taxpayers to fund transmission networks and backup systems for renewables, we might get a true indication of what is the cheapest way to generate electricity and reliably deliver it 24/7 to customers and industries.
The cheapest electrical generation continues to be simply building an additional boiler module in an existing coal fired power station because 80% to 90% of the equipment, people, technology, transmission circuitry and services are already there. I wish this wasn't true, but it is.
Understandably, we don't want coal, so we rig the system against coal and keep telling lies about the true all-up cost (including subsidies etc) of delivering reliable electricity to customers from intermittent renewables that are usually located in remote places so that rural communities bear all the social costs of having the toxic renewable solar panels, wind turbines and power transmission lines across their land. We need to tell the truth that renewables cause energy costs to rise signficantly and destabilise the grids and then let the community decide what is best. I hope communities are mature enough to make the best choice rather than have a "dodgy strategy" imposed on them.
I will believe that renewables are the best strategy when I see solar panels and wind turbines built without subsidies and located in wealthy suburbs rather than in poorer fly-over regional areas. Once renewables reach 25% to 30% of the electricity supply, building more nuclear and operating cleaner coal plants longer while the nukes are being built is a reasonable transition strategy.
"a few billion for a transmission line has led to of order 20 times as much investment in building solar"
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The success of west Texas wind and solar farms owes a lot to major transmission lines constructed beforehand. Additionally, ERCOT's model has encouraged the construction of private arbitrage grid battery storage, which has spared us from rotating blackouts in the increasingly hot summers.
From https://www.ercot.com/gridmktinfo/dashboards you can see the storage charge discharge pattern for most summer days here:
https://www.ercot.com/gridmktinfo/dashboards/energystorageresources
Thanks for this post! I think this is an important discussion to have. In the last post on my own blog I also highlighted stratospheric aerosol injections and how they might interact with something like nuclear winter, might be worth also checking out if the topic is of interest: https://existentialcrunch.substack.com/p/manipulating-the-global-thermostat
The analysis presented makes sense in the abstract, but in the real world the risks are enormous and probably uncontrollable. The implicit assumption here is that rational, ethical government actors -- who understand and respect science and the rule of law, and who prioritize global well-being over narrowly perceived self-interest -- will collectively control decision-making about deployment of, and limits on, SAI. Unfortunately, based on history and the daily news, we have every reason to think that will not be the case. Small-scale rogue actors are one legitimate worry; but powerful countries with rogue leaders are a larger, more dangerous, and more intractable concern.
I believe Kim Stanley Robinson used this as part of the plot of Ministry of the Future.
He did, after a heat wave in India killed millions. Though the scenario he envisioned was not quite as narrowly bounded.
My understanding is that the SOO Green line has all the approvals and materials, etc. to get started. What it lacks is high level Administration approval as it is basically carrying wind power to the grid. The delay is very unfortunate and that the reason for it is political and not technical is disgraceful.
I think the most compelling arguments for it are 1) just how long elevated temperatures will be with us. If we wind up at 2.5 degrees above pre industrial levels, it will be hundreds of years until it cools back down. If we all agree that would be a bad outcome, geoengineering will be able to keep the planet cooler (until we can remove the CO2 as you say). 2) tipping points. If we can cool the planet and stop the ice caps melting, that would also be very beneficial.
Both of these outweigh any moral hazard arguments IMO, which I just don't find that convincing given the trends in solar + storage. By the time we deploy geoengineering, the tools we have to cut emissions will be well on their way to doing so (if not quite as fast as we would e).
We're on the same curve where money available to fix things is in competition with money needed to respond to disasters, or money lost to things like housing market collapses and their resulting decline in property tax revenue. (Conversely, had we started working on this this a couple of decades ago, it would have been much cheaper and easier. Instead we sacrificed it all on the altar of the fossil fuel industries' "shareholder value" god.)
I am intrigued by the proposal to conduct limited geoengineering for a few reasons. One that I haven't heard yet is the opportunity to see whether the tests would encourage continued high rates of CO2 uptake by the ocean. Currently, the ocean absorbs CO2 at rates that are directly proportional to atmospheric levels -- with a high r-squared term -- so one should expect to see this continue even as we reach "peak anthropogenic CO2 emissions", which could be any year now.
(By the way, the IEA has pointed out that the reason that we have been "bending the CO2 emissions curve" over the past 10+ years is that we are learning to reduce the cost of modular, low-carbon technologies, like heat pumps, fuel cells and photovoltaics... so that when built in sufficiently large numbers, they become economically-preferable to older, fossil energy technologies that were dependent on economies of scale.)
Another thought concerns the extent to which geolocation and timing matter. For example, would stratospheric sulfur injection in the northern hemisphere polar region, during spring and summer, help preserve polar ice (including Greenland's glaciers, which also suffer from seasonal feedback loops)?
A few years of solar geoengineering seems like an opportunity to briefly limit warming, develop a greater understanding of ocean uptake (including limitations of the biological carbon pump) and perhaps see whether we can influence the loss of polar ice.
Limiting cooling from geoengineering to avoid weather event effects is a necessity; that means it cannot have a major impact on warming, but only a smaller one. I believe that having ships (and planes?) spray saltwater or other chemicals to raise small, local cloud reflectivity can be helpful and not too expensive while avoiding climatilogical horrors. Do you agree?
I have wondered if self-powered facilities at sea—especially near the equator—could produce steam plumes (aka "clouds") with relatively high reflectivity.
Zeke, I like your novel approach of proposal stage after implementation.
This is an important question - thanks for addressing it in public forums. If we go ahead with it, who’s “we?” Should the US do it alone? China? Russia? The UN (imagine the howls against “world government”)? How do we keep track of how much sulfur is injected? The same questions probably apply more or less to any other mitigation strategy.
Not just "world government," but the dreaded "chemtrails"!
I agree with this statement: "We are already geoengineering the planet today, but badly."
But when I read that I thought it was to point out that the large scale emissions of GHG is the most significant and dangerous geoengineering experiment that we are doing today and committed to do for decades more. Like aerosols, GHG emissions are a by-product of energy use.
The important question from a moral (and legal) perspective is how long we can really call GHG 'unintentional' and 'byproduct'. We have known for a long time now what the impacts and risks are related to continued GHG emissions. We have technologies to mitigate, reduce and even remove emissions. The main reason we are not doing that is the costs. We need to get tougher on atmosferic pollution. Unfortunately, the opposite seems to be happening. I agree with you, band-aids are not the solution and carry a high 'slippery slope' risk.
https://www.linkedin.com/pulse/report-from-blue-planet-margriet-kuijper/
Are you really questioning the fact that GHG emissions from fossil burning are unintentional? Calling that an experiment requires a failure to understand what the word means. You're right that we have known far too long now what the impact of GHGs from fossil burning are, but we cannot simply stop burning fossils overnight. And your "technologies" for GHG mitigation, reduction and removal, are likely the ones (CCS, BECCS, DAC, etc.) we all know are unscalable and fraught with other problems as well, unless you have other ideas in mind, such as a complete re-do of our social and economic goals to end our growth lust and start behaving like we live on a finite planet.
GHG emissions from fossil fuel emissions were definitely unintentional when we started using them. Or better worded: the impacts of these emissions were not widely known and therefore unintentional.
However, we have known now for at least 30 or 40 years (governments, companies). So it is justified to ask the question if we can still call it 'unintentional'.
Not sure what you mean by "your technologies"? The are not 'mine'. But they are critical technologies if we want to stop fossil fuels causing climate change. Just like solar, wind, batteries, nuclear are technologies that are needed to reduce fossil fuel demand.
Abatement technologies do exist and could be scaled up much faster if we really do not like 'experimenting' with our climate.
Your "better worded" addition is right. Emissions are STILL unintentional when we burn fossils. I understand that you are not intending to say that we literally are trying to emit GHGs when we cook or drive or any of the other ways we use fossil energy. And I understand that you do not literally mean that our use of fossils for fuel is an experiment. I just think that it is not meaningful to say such a thing just because we are now well aware of what is happening. We as individuals literally have no choice of what fuel to use in nearly all of our occasions of fossil burning for energy. But I am surprised that you are okay with that usage but then you call me out for saying “your” technologies, which is also clearly not meant to be taken literally.
No, they obviously are not your technologies. Whether they are "critical" or not depends on who you believe. The IPCC calls virtually nonexistent strategies like BECCS and DAC "required" and "unavoidable" despite the fact that it seems to be the scientific consensus that these strategies are simply pipedreams when it comes to scaling them to the vastness envisioned by the IPCC authors. So-called "roadmaps," whether they are done by the IPCC, IEA or Lawrence Livermore are better described as wish lists, as feasibility studies for their global implementation haven't really been carried out.
Talking about these solutions (or like Zeke's claim that we can pull together and stay below 2C) as though they are feasible is great if you want to succeed on a political level, or to be awarded funding for projects, but when it comes to reality? Not so much.
Why do you write, "The world can still come together and rapidly reduce emissions to limit warming to well-below 2C this century." Is there some science to show that this is possible in practical terms. The rate of reduction necessary could/would collapse economies and so would rapidly be stopped, in favour of growth (unfortunately). Is there a way of rapidly reducing emissions without collapsing economies?
No, its just complete hopium. We already did 1.5 and will be doing 2 late next decade. Short of a revolution to overthrow the richest 10% who produce 50% of the emissions and whose wealth is utterly tied up in assumptions of future economic growth.
Recently I have been reading about the agricultural aspect of climate change, and have learned that that contributes about 30% of the total effect (fossil fuel use is the other 70%). Every acre of agricultural use means one less acre of trees. Trees are a great (the BEST ?) way to remove CO2 from the air. About a quarter of the food (worldwide) is thrown away. Not throwing food away (feeding excess food to hogs, for instance) would allow a huge extra withdrawing of CO2 annually, via the trees that could be restored. A bigger factor in agriculture is the use of ruminants (cattle, sheep, etc). Ruminants use half of the agricultural land world wide. Cutting back significantly on the use of ruminants would free up MANY more acres for trees to annually remove CO2. Would you consider writing some articles on this aspect of climate change? (I'm new to The Climate Brink and don't know if you have already covered this area.)
There is a lot of research on this subject. Certainly, we are wasting far too many resources on raising livestock. Eating animals given our current situation isn't workable anymore on such a scale, especially considering the increasing living standards of many of the world's poor are leading them to be new meat eaters. But when it comes to trees, what is most helpful is protecting existing forests from being levelled (for example in order to plant soya or raise livestock) and secondly, to end grazing on former forest land and helping it to rewild. What is troublesome is the idea to plant monocultures of trees which then don't promote an increase in biodiversity, particularly in areas that had not been forests. Many projects like this fail to lead to a lasting forest and often result in trees that grow for a while and then whither. Demands on irrigation for such man-made forests is also a huge problem.
I'd amend that to saying that >healthy< trees are the best way to remove CO2, since those stressed trees burned in massive crown wildfires* are a good way to >add< CO2. ☹️ We're even losing sequoias, which in the past were considered extremely fire-resilient.
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*Watch out for doubt-slingers who point to the larger >area< of grassland, underbrush and agriculture fires in previous centuries. The combustion volume of these big wildfires is much, much higher than a grassland fire for the same acreage.
If we're talking about "geoengineering", why limit the discussion to atmospheric sulfur injection and not consider alternatives with less downsides such as ocean photosynthesis?
https://www.onepercentbrighter.com/p/the-no-bullshit-way-to-repair-the
Zeke, please do explain just how you think we can "come together and rapidly reduce emissions to limit warming to well-below 2C this century" when considering that the EEI has been growing at about 0.08W per m2 in the past 2 decades, leading to 0.1°C additional locked-in warming per year. We have 25 years until 2050, so if historical trends continue, we would have an additional 2.5°C locked in, IN ADDITION to the 1.7°C locked in by the current 1.4W per m2 of EEI. So locked-in warming by 2050 would be 4.2°C over a century scale, but over 10-20 years we have about half, so about 2°C more: 1.5°C +2°C =3.5°C.