A Dangerous Disruption
A startup firm proposes to sell dubious carbon credits from stratospheric aerosol injection
Last week, MIT’s “Technology Review” reported that a small startup firm is proposing to spray reflective aerosols within the stratosphere commercially as a climate corrective. (Stratospheric Aerosol Injection or SAI.) Previously announced online within the Google Geoengineering Group, the firm is small and latest, operating with a claimed total of $750K of enterprise financing. They are saying they’ve up to now launched two small weather balloons, which each released just a few grams of sulfur dioxide gas (SO2) within the stratosphere. They assert that their activity will provide two advantages. First, the cooling from the reflective materials they’ll inject, for which they’re already selling carbon credits, charging $10 per gram of SO2 released (!) Based on easy calculations from a recent scientific paper, they claim that every gram of SO2 will offset the heating effect of 1 ton of CO2 emissions for one 12 months. (The “for one 12 months” part is crucial: stratospheric aerosols stay within the atmosphere roughly a 12 months, so one gram offsets the heating effect of 1 ton just for the primary 12 months after the ton is emitted. After that, the sulfur is gone however the CO2 remains to be there and heating.) As a second profit, they claim to be engaged in political symbolism, attempting to disrupt a stuck debate over effective climate responses and get people to discuss solar geoengineering – of which stratospheric aerosol injection is essentially the most promising method being discussed.
This news will not be particularly surprising. Those following debates on lively climate interventions have been expecting – and worrying about – something like this for just a few years. The prospect of climate interventions, particularly SAI, might offer large reductions in climate-change risks that aren’t possible through emissions cuts, adaptations, or atmospheric removals alone, but in addition raise serious latest uncertainties, risks, and governance challenges. Yet proposals to expand research and begin governance consultations have met stiff opposition, so little progress has been made in understanding intervention methods and their potential contributions, risks, or governance. The state of understanding and debate thus exhibits an odd dichotomy. On the one hand, the fundamental mechanism of how stratospheric aerosols can cool the climate is well understood, with some volcanic eruptions providing natural analogues that put rough bounds on efficacy and risk. There are thus strong grounds for confidence that interventions could possibly be made to work. At the identical time, there stays deep uncertainty about methods to actually do interventions effectively and safely, limit associated risks, and control them effectively, prudently, and legitimately. Yet calls to do the research and governance consultations needed to construct understanding and capability, and to supply the needed resources, have met stiff opposition and achieved little progress. (This will be on the cusp of adjusting, nevertheless it hasn’t yet.)
This near-blockage of research and policy debate on SAI strangely co-exists with a flood of technical proposals, startup firms, and money (private and public) flowing into atmospheric removal of CO2 and other greenhouse gases (carbon dioxide removal, CDR) – interventions that despite big differences in specific methods, risks, and advantages, are sometimes lumped with SAI under the broad heading, “geoengineering.” This CDR boom comes with a gold-rush of carbon-credit proposals, based on technologies and business models starting from the highly credible and potentially precious, through to the wildly exaggerated or potentially fraudulent. In such an environment, it’s hardly surprising that somebody comes along to leap in and disrupt a dangerously stalled debate on SAI, and jump on the carbon-credits gravy-train at the identical time.
In a rare little bit of agreement in an often fractious debate, nonetheless, nobody knowledgeable about SAI thinks what this firm is doing is an excellent idea. Reactions to the firm’s plans – from those that categorically reject research or policy discussions on SAI through a range of views to those who think research and expanded debate are essential and urgent – have been uniformly critical. (Note: That is all the range of debate: Nobody prior to this proposal has supported any near-term move toward operational use of those interventions.)
So what’s the issue? What’s incorrect with what the firm is doing, and why are the reactions to such a tiny activity so strong? We don’t have full details about what they’re proposing, but based on the knowledge available we are able to make just a few conjectures.
First, there are some concerns which are serious for the prospect of unauthorized SAI interventions usually, but aren’t serious concerns for what these folks are doing. This activity cannot have any significant global climate effect. And in all likelihood, they aren’t breaking any current law or regulation.
Could this activity change the climate? Estimates of how much aerosol should be injected to limit climate change vary widely with background scenario assumptions (how briskly are emissions being cut) and the way much cooling is sought, but they’re all on order hundreds of thousands of tons injected, costing $10 to $20 billion, annually. The 1991 eruption of Mt. Pinatubo, widely used as an analogy for SAI, put about 15M tons of sulfur aerosols within the stratosphere and cooled the Earth a bit lower than 1°C over the next 12 months. The brand new firm’s initial launches each injected just a few grams of sulfur – far lower than the sulfur emitted from one trans-Pacific airline flight (~ 50-100 Kg S, depending on the fuel’s sulfur content). Even assuming the utmost weather-balloon payload of just a few kilograms per launch, getting an observable climate impact from these would require lots of of hundreds of thousands of launches per 12 months. While this might be technically feasible, it’s implausible to assume this scale of activity without the knowledge and participation of states. And if states were involved, they might use dedicated aircraft to disperse the identical amount – with more control, less environmental impact, and at much lower cost. (Cost estimates for these things are rough and preliminary, but using aircraft looks about five times cheaper than weather balloons.) In a 2019 scenario exercise examining governance responses to 4 scenarios of unauthorized SAI deployment, the scenario of a widely distributed grassroots effort using weather balloons was the just one the expert participants rejected as pure political symbolism, unable to attain a meaningful climate impact.
That the firm’s activity might be not breaking any laws is closely related to its tiny scale. Launching weather balloons is a really calmly regulated activity, pursued by hobbyists and citizen scientists in lots of countries. In the USA, you don’t even need a permit for individual launches, as long as you retain the payloads small (the few Kg for which weather balloons are designed), don’t fly an operating cellphone, don’t drop anything with no reliable parachute, and steer clear of busy or controlled airspace. (Relevant FAA regulations here, FCC regulations here, with a transparent summary from a citizen-science NGO here). The tiny quantities released from each balloon would also escape existing environmental controls, either by falling below de minimus numerical thresholds or by not falling inside specific identified categories of regulated activity. Multiple domestic laws and international treaties are “relevant” to the activity, nevertheless it doesn’t fall under their specific concrete controls. If the mixture scale of the activity expanded so much or got here to involve significant government participation, it might very likely fall under environmental impact assessment requirements. But at present, and under any reasonably likely expansion, it appears to not be violating any law.
So if it may possibly’t have a big climate or environmental impact, and it’s not breaking the law, what’s the issue? Is that this only a silly distraction, or could it do actual harm? In my opinion, it could do real harm, but this harm would come not from any direct impact of the releases – that are trivial for good or in poor health – but from its seeming precedent and the way it’d influence larger climate debates. There are just a few grounds for objection.
First, whatever your view on the merits or risks of SAI usually, it’s a highly unsuitable activity for pursuit by industrial enterprises. Any deployment strong enough to do anything will affect all the world: effects can’t be spatially confined. Specific effects, globally and regionally, will depend upon detailed deployment decisions: how much is finished, when, where, and the way. Given their universal impact, these decisions must be made intentionally, with consideration of effects, via some legitimate process with input from affected publics and accountability. Given present uncertainties about methods, their effects and risks, there isn’t a strategy to assess claims about what was done, how successfully, with what uncomfortable side effects, and with what false starts, mishaps, and failures. And there may be loads of incentive for self-interested actors, particularly those with revenues on the road, to misrepresent these. Nothing about this process, except perhaps specific elements of implementation under some hypothetical future governmental or intergovernmental control, might be entrusted to personal firms.
Second, attempting to integrate SAI into emissions and removals accounting by selling carbon credits is a terrible idea. The firm’s easy calculations to support their “1 gram equals one ton’s effect for one 12 months” are based on widely accepted approximations, but these are miles from being reliable enough for either industrial or regulatory purposes.
Much more seriously — and in contrast to removing greenhouse gases from the atmosphere — SAI perturbs the climate differently than greenhouse gases. SAI can offset the consequences of greenhouse gases on global-average temperature, but not their total climatic and environmental effects. It thus can at most function a stopgap measure that buys time to expand emissions cuts and removals, not an alternative to these. Issuing credits counted on the identical scale as emissions and removals obscures this fundamental difference, and increases the chance that SAI might be wrongly taken as a whole alternative for these essential activities. Such a misunderstanding is particularly dangerous because these credits could be less expensive than those related to emissions cuts or removals: if freely exchangeable, they might drive these other activities out of the market.
There’s an urgent need for more research on SAI, including field experiments. But this firm’s launches aren’t designed to generate credible answers to vital scientific questions. They don’t control the placement or conditions of release, nor monitor what happens after they release the fabric. These fundamental limitations make the launches useless for research. The firm’s invitation for researchers to propose observational systems for them to include doesn’t solve the issue: well targeted research can’t be done as a bolt-on extra for a project conceived as an operational deployment, nonetheless tiny. And for the reason that endeavor is already marketing credits as if the consequences were known, reported results won’t be trusted.
In sum, private firms shouldn’t be plunging ahead with SAI or other types of solar geoengineering. They will’t know with any confidence what the consequences of their releases are; the carbon credits they’re promoting are worthless; and the activity is neither directed toward nor useful for scientific research. It risks identifying solar geoengineering with reckless, ill-informed startup culture, hindering and discrediting by association serious efforts to get needed research and governance consultations underway. There may be one countervailing positive effect. With research on SAI and consultations on its governance long stalled and progressing very slowly, a disruption like this – symbolically vital but too small to do any direct harm – might galvanize the research and policy communities and get more serious pursuit of those needed activities. But related to this potential profit is the chance that this announcement provokes a hostile public response that sets back the intense SAI research and governance efforts together with the unserious ones.