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Mexico Bans Solar Geoengineering Experiments

Updated: Feb 1

Should governments try to artificially cool the planet through ‘climate engineering’, for instance by injecting tons of sunlight-reflecting sulfur particles into the stratosphere? While some scientists seriously suggest that ‘solar geoengineering’ should be part of future climate policy, the government of Mexico has now taken a different stance: it has decided to ban all solar geoengineering experiments over its territory (unofficial English translation here).

Mexico’s new policy was triggered by an alarming recent development: the launch in late 2022 of a first commercial programme for the deployment of solar geoengineering technologies by a private company in California. This start-up, called ‘Make Sunsets’, claims to have conducted two balloon flights in 2022 and to have planned at least three further flights in January 2023, each injecting between 10 and 500 grams of (supposedly sunlight-reflecting) sulfur into the atmo­sphere. The rationale advanced by Make Sunsets is straightforward: If you are concerned because you emit carbon by driving a car, catching a flight or overheating your home, you can simply transfer a few dollars to Make Sunsets, which will send balloons with sulfur up into the stratosphere to block a bit of sunlight and hence ‘compensate’ for your emissions.

This kind of experiment shows all that is wrong and dangerous about solar geoengineering.

For one, there is zero accountability and no information about what has happened. We do not know where the balloons ended up or what they have emitted. There have been no impact assessments or public controls whatsoever. No government was informed, not to speak of any international consensus or United Nations approval.

Second, the Californian company chose to launch their balloons not from US territory but from neighbouring Mexico (possibly fearing legal or public repercussions in the United States). This choice for using Mexican territory reflects the colonial history of rich countries using land in the Global South for exploitation, expropriation and experimentation – and now for testing out climate engineering technologies in Latin America without any prior information or consent. The speed of Mexico’s reaction shows the government’s alarm about this misuse of their land by private actors based in their Northern neighbour.

Third, Make Sunsets clearly lays bare the dangerous logic behind solar geoengineering: Make Sunsets is a commercial carbon offset programme, financed by venture capitalists in the United States and targeting the purse of the climate-concerned public. The starting investment they request is small; for just ten dollars they promise to offset the emission of one tonne of carbon dioxide for one year, an amount that equals 6-7 percent of the average annual emissions of a US citizen. If you are a bigger emitter, for example a company, school or local government, Make Sunsets offers ‘bulk pricing’. All quick payment options are available, from PayPal to most common credit cards.

Carbon offsetting by other means has been big business for long. To give an example, the German company Atmosfair, one of the more credible outfits in this industry, offers to offset the carbon emissions of a return flight Amsterdam-San Francisco for 108 Euros by financing for instance solar energy plants in Morocco. Make Sunsets now drives such business models to a new extreme: instead of offsetting carbon emissions by helping local communities or industries to decarbonize, they promise to simply dim the sunlight – and this for only a few dollars.

Importantly, the offset that Make Sunsets offers promises to mask carbon dioxide emissions only for one year – while carbon dioxide, once emitted, stays in the atmosphere for centuries, if not millennia. Therefore, theoretically anyone seeking to offset their current emissions with Make Sunsets would need to pay the same annual amount for more than a century, beyond their own lifetime and presumably beyond the operation of the start-up. And this payment over long durations would be needed for all further emissions, again and again. Offsetting just one transcontinental flight with Make Sunsets would thus entail, over the course of a century or more, costs that would exceed several times the costs of the ticket. The non-feasibility of this kind of business model is obvious.

What is more, solar geoengineering technologies offered by private companies would be available for any other commercial actor, now and in the future. Who will stop ExxonMobil, which has lied about their insights into the climate problem for decades, from offering a solar geoengineering offset that comes with their oil? Who will stop Delta Airlines from compensating their entire airline fleet by blocking a bit of the sunlight as compensation? Who will prevent entire countries from entering solar geoengineering into the climate debate and arguing that their high emissions and economic growth would require them ‘to buy time’ by geoengineering the planet until they have figured out how to decarbonize their economies at a lower cost?

Make Sunsets shows at small scale how solar geoengineering would function and what ends it would serve in a global capitalist economy that lacks an effective and just global governance system. It is not surprising that solar geoengineering research has most supporters and funding in a country with one of the world’s highest per-capita carbon emissions, with each American emitting 14.7 tonnes of carbon dioxide on average per year, as opposed to the average Indian who emits only 1.8 tonnes. Solar geoengineering could be seen as the pipedream of a cheap transition strategy for rich countries that overuse, overconsume, and are unwilling to change.

Many of those who are calling for more research on solar geoengineering now rush to argue that they have nothing to do with this first rogue deployment of geoengineering by corporate actors. Yet it is, in fact, their own research that underlies many claims by Make Sunsets and has presumably informed the Californian venture capitalists Boost VC, Pioneer Fund and others that have made this first climate engineering company possible.

A huge body of academic literature shows the many risks, both environmental and political, that come with geoengineering. These planetary climate interventions cannot be controlled, and their local, regional and global impacts are uncertain, with innumerable threats to regional climate systems, food security, water systems and so forth. Solar geoengineering should not be part of future climate policy, and all development, testing and rogue deployment needs to stop. Over 390 academics from 54 countries, supported by NGOs from all regions of the world, have signed in 2022 an Open Letter that calls upon governments, the United Nations and other actors to support a global ban on the development of solar geoengineering technologies, similar to the many existing bans on biological weapons, Antarctic mining, anti-personnel landmines, the export of hazardous waste or the production of substances that destroy the ozone layer. What is concretely needed, the open letter argues, is an International Non-Use Agreement on Solar Geoengineering.

It is Mexico that now leads the way, as the first country to announce a ban on experiments with solar geoengineering technologies. The Global South must not become the testing ground for dangerous techno-fixes cooked up in Global North laboratories and financed by venture capitalists from Silicon Valley.

Other governments might now want to follow the lead of Mexico and also ban the use of their territory for reckless geoengineering experiments. A series of unilateral declarations by governments, NGOs, parliaments and others that speak out against solar geoengineering experiments could send a clear signal to venture capitalists and fossil fuel companies that climate hacking will be no alternative to rapid and deep decarbonization. And within the UN system, the negotiation of an International Non-Use Agreement on Solar Geoengineering must urgently be placed on the global political agenda with multilateral negotiations towards a global ban starting in 2023.

As the 2022 Open Letter of 390 academics argues, ‘Solar geoengineering is not necessary. Neither is it desirable, ethical, or politically governable in the current context. Given the increasing normalization of solar geoengineering research, a strong political message to block these technologies is required. An International Non-Use Agreement on Solar Geoengineering is needed now.’

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