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Solar geoengineering technologies are likely to be adopted by more governments to mitigate global warming effects

This assessment was issued to clients of Dragonfly’s Security Intelligence & Analysis Service (SIAS) on 13 June 2023.

  • Current evidence suggests usage by a country can have adverse consequences on its neighbours
  • This shows the technology has a high potential to exacerbate geopolitical tensions, and interstate and civil conflict risks

As global temperatures rise, some states are exploring extreme counter-measures. This includes researching, testing and possibly deploying solar radiation management technologies (also known as solar geoengineering – SRM), which aim to offset some effects of global heating by reflecting more sunlight into space. The consequences of using these technologies are highly uncertain. And more governments, including the US which carried out a wargaming exercise centred on SRM in late 2022, are becoming concerned about the national security implications.

While it is plausible that there are some benefits, the use of SRM technologies is also highly likely to carry significant environmental and geopolitical risks. That is apparent from the focus of the US exercise, which considered managing the diplomatic and military tensions that would arise from a unilateral SRM deployment. And the 2021 climate change-focused US National Intelligence Estimate warned that the unilateral testing and deployment of large-scale solar geoengineering risked creating a new area of geopolitical disputes.

Solar geoengineering offers solutions but is largely untested

The negative impacts of climate change are occurring faster than scientists predicted less than a decade ago. Faced with the increased frequency and severity of climate extremes, a more fractious international policy landscape, and growing domestic pressure to more effectively manage the climate crisis, some governments are likely to explore more desperate responses. One includes going at it alone by unilaterally developing and deploying SRM technologies.

Solar geoengineering technologies – such as stratospheric aerosol injection, a controversial form of SRM – are becoming a more polarising issue among scientific and policymaking communities. This is partly because research and deployment of this type of climate intervention sits outside the reach of existing international law. There are currently no binding international protocols that fully cover solar geoengineering deployment, despite its potential to lead to harmful impacts across national borders.

SRM technologies also remain largely unproven. And the interconnected nature of the climate system makes unintended consequences of SRM technologies very likely. Studies by the UN and several think tanks expect SRM side effects to include adverse localised climate implications, such as less predictable and potentially extreme changes in regional precipitation patterns. Those can undermine food and water security.

Given that most SRM approaches have yet to be tested at scale, uncertainties remain over how such second-order effects would manifest. Impacts that may be good for one country, such as increased rainfall during a critical growing season, for example, are not guaranteed to be good for its neighbours – for example, if this were to lead to increased flooding downstream. Another concern, according to the UN’s Intergovernmental Panel on Climate Change, is that any sudden termination of SRM technologies gives rise to further shocks, including abrupt warming and ecosystem disruption.

SRM research is highly divisive

SRM experimentation is continuing unchecked, however, in the absence of a consensus on which international processes or institutions can make decisions on whether to deploy solar geoengineering. In September 2022, researchers in the UK launched a high-altitude weather balloon that released a few hundred grams of sulphur dioxide into the stratosphere. According to the MIT Technology Review, this was a potential first in the solar geoengineering field and took place in spite of concerns from the UN and others about the technology.

Debate within scientific and policymaking communities will probably centre on the need to set standards and norms for SRM research. Some – including the UN’s environmental programme – advocate for a robust, equitable and rigorous trans-disciplinary scientific review process to reduce associated uncertainties. Whereas some national authorities are likely to call for an outright ban on solar geoengineering. This happened in Mexico in January after a US startup released sulphur particles into the atmosphere in the country.

The capability of solar geoengineering is currently concentrated geographically, with research being undertaken within only a few countries. Australia, China, India, Russia, the US, the UK and several EU member states are currently the most involved in exploring geoengineering techniques. But it is possible if not probable that governments in more countries will advocate for SRM experimentation during the next few years.

Support for SRM is likely to grow

Future supporters of SRM will probably point to its theoretical affordability and feasibility. The UN in February estimated that the direct costs for deploying SRM could be tens of billions of US dollars per year for every 1°C of cooling. This is considerably less than the total cost of delivering the global transition to a low-emissions economy, which the UN has separately suggested will require investments of at least $4-6 trillion a year.

Proponents are likely to include governments in countries such as China and India. Both have high exposure to climate change impacts but are less committed to taking action on the causes of climate change as they perceive cutting emissions will derail their development. Petro-states, whose abilities to provide social benefits to their populations are underpinned by oil wealth, will also probably view alternatives to the global transition to low-carbon energy sources favourably. This would include Saudi Arabia and the UAE, which are already involved in operational programmes to modify the weather.

A new area of geopolitical disputes

Geopolitical tensions over solar geoengineering will probably intensify towards the end of this decade, particularly if key governance and regulatory gaps are left unfilled. In September, the UN General Assembly will provide a forum for policymakers to discuss the risks pertaining to the lack of governance around SRM. But international agreements often take years to negotiate. It is also unlikely that those countries whose governments favour using SRM will adhere to any guidelines out of self-interest.

Efforts to govern SRM will therefore probably trail behind the accelerating pace of innovation into the long term. This makes it plausible in our assessment that governments will deploy such technologies at scale by 2030. The net impact of such a deployment will probably be greater potential for conflict within and between countries, especially if one community or state perceives its interests to have been negatively affected by the use of SRM by another.

Solar geoengineering may also be used as a scapegoat by some authorities that fail to adequately prepare for or manage future climate hazards. It is possible if not probable that this decade, one or more governments will blame a neighbour’s use (or alleged use) of SRM for their own misfortunes or failings.

Image: A commercial airline flies past the sun covered in haze made from smoke of Canadian wildfires in Washington DC, United States, on 7 June 2023. Photo by Anna Moneymaker via Getty Images.