Tech Talk | Solar geoengineering, not in Europe – for now at least
Image: Asher SRI
Solar geoengineering, or solar radiation modification, should not be deployed at present by the EU, scientists have recommended.
Given the current state of knowledge, the technologies could have many effects, both intended and unintended, and the benefits and risks are highly uncertain, the EU’s Group of Chief Scientific Advisors (GCSA) have reported in advice requested by the European Commission.
Solar geoengineering, or solar radiation modification, has long been suggested as an approach to reduce the incoming solar radiation as a means to limit global warming.
It has its precedent in cloud seeding, which has been practiced for modifying the weather on a local scale, currently in around 50 countries, particularly for increasing rainfall in otherwise drier areas.
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But solar engineering, to have any effect, would need to be on altogether different, larger, scale, with technologies suggested ranging from the injection of aerosols into the stratosphere to the brightening of low altitude clouds or thinning of high altitude clouds or the placing of giant shields out in space between the sun and Earth.
At the time of our last commentary on the topic in March 2024, the ‘Cool Earth’ initiative at the Asher Space Research Institute in Israel was making news, with the proposal to place a massive shade over 2 million km2 in extent at the inner Lagrange point about 1.5 million km distant from the Earth in the direction of the Sun, where it would remain in a close-to-fixed position.
The Institute’s website currently details its activities as developing a technology demonstrator mission.
While its progress is yet to be seen, other projects, such as the Bill Gates-backed SCoPEx project at Harvard University to test aerosol seeding in the Arctic, have had to be shelved, in this case apparently due to public pressure.
Symptoms, not causes
In their review the scientists point to these technologies addressing the symptoms rather than the root causes of climate change.
“At best, they would reduce warming from solar radiation on a temporary and local scale, while greenhouse gas concentrations and ocean acidification continue to increase,” they state.
They add: “Solar radiation modification would be likely to bring substantial negative ecological and economic effects, including changing patterns of rainfall, impacts on ecosystems, a decrease in the security of food production, and a decrease in the potential of solar energy.”
They also note that as the effects are global, any large-scale deployment would fall under international law and regulations of the Earth and outer space but as yet there is no such international framework.
Recommendations
The scientists present five main recommendations.
One is to prioritise reducing greenhouse gas emissions as the main solution to avoid dangerous levels of climate change, i.e. to continue to treat emissions reduction and adaptation to climate change as the highest priority in reaching net zero by 2050 and to continue to invest in R&D on climate mitigation and adaptation.
An EU-wide moratorium on the use of solar radiation modification as a measure for offsetting climate warming should be agreed, acknowledging that there is currently insufficient scientific evidence on its effect and recognising the uncertainties associated with its possible deployment.
A global governance system for the deployment of solar radiation modification should be proactively negotiated by means of a multilateral process with international legitimacy, including carrying out a broad public consultation and ensuring that the risks of militarisation are addressed.
Research on solar radiation modification should be ensured to be conducted responsibly, with scientific rigour and in accordance with ethical principles in research, with the creation of clear ethical requirements and development of guidelines for outdoor research projects and a moratorium on large scale outdoor experiments.
Last but not least, the scientific evidence on the risks and opportunities of solar radiation modification research and deployment should be reassessed periodically, every 5-10 years.
Support for the participation of the scientific community in intergovernmental assessments should be considered, citizens’ assemblies should be set up to initiate debate and promote transparency and the development or adaptation of detection-attribution modelling tools should be supported.
Jonathan Spencer Jones
Specialist writer
Smart Energy International
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