Researchers at HSE University and George Mason University have investigated the sustainability of prospective international agreements on solar geoengineering. The authors have proposed a scheme in which payments flow from affluent nations to less wealthy ones; an arrangement which sets their proposal apart from traditional systems. The proposed model aims to dissuade more vulnerable countries from excessive use of the prevalent geoengineering method by providing compensation for the potential damage they may incur and supporting their adaptation to climate change. The paper has been published in Environmental and Resource Economics.
Solar geoengineering, also known as solar radiation management, is an approach to combat climate change resulting from high concentrations of greenhouse gases in the atmosphere. This method is regarded as a temporary measure to prevent catastrophic temperature increases while allowing countries to reduce greenhouse gas concentration by gradually lowering their emissions. The key concept behind solar engineering is to reflect a portion of solar energy back into space. Multiple potential solutions have been explored for this approach, ranging from marine cloud brightening to the installation of reflective surfaces in space, but recently scientists have been particularly focused on the stratospheric injection of reflective sulphate aerosols. A similar natural phenomenon occurred when global cooling resulted from sulphur emissions following volcanic eruptions on Earth. The current plan involves intentionally spraying reflective aerosols into the stratosphere.
However, this method is associated with potential side effects, including, among others, alterations in precipitation and an impact on the stratosphere's chemistry and the microphysics of clouds. Furthermore, the level of aerosols in the stratosphere must be sustained through regular spraying; otherwise, there is a risk of a rapid temperature rise, which could be far more detrimental than a gradual increase. This means that the success of this method depends on having effective mechanisms for preventing excessive aerosol use, coupled with active participation of a majority of countries in a relevant international agreement.
Attaining effective and sustainable global agreements on climate issues is usually extremely challenging. As a solution, economists have suggested a system of international transfers—or 'participation payments'—flowing from those with a greater need for an agreement to those with a lesser need. Since countries with lower GDPs tend to be more susceptible to the adverse effects of climate change and therefore particularly interested in international agreements aimed at mitigating emissions, the concept of 'participation payments' implies a flow of funds from economically disadvantaged countries to wealthier ones, which contradicts the goal of reducing economic inequality, besides being unfeasible in practice. But as far as solar radiation management is concerned, the situation can be different.
Researchers Irina Bakalova at HSE Faculty of Economic Sciences and Mariia Belaia at George Mason University have designed a model of international transfers which is capable of achieving a sustainable agreement on solar engineering. In their model, cash flows from wealthier countries to less affluent ones. According to the authors, the proposed scheme addresses the fairness challenge, a central issue in climate negotiations between the industrialised countries of the Global North and the developing economies of the Global South. The model aims to dissuade more vulnerable countries from excessive use of stratospheric aerosol injections by providing compensation for potential damage and supporting adaptation to climate change. The researchers emphasise the importance of countries' willingness to contribute substantial amounts towards a voluntary agreement to establish a dedicated fund similar to the Loss and Damage Fund agreed upon at the 2022 UN Climate Change Conference.
While the most vulnerable countries have incentives to overuse stratospheric aerosols, the suggested payments aim to compensate them for any extra damage they might incur by agreeing to reduce aerosol amounts and, consequently, experience higher average temperatures.
The study suggests that international transfers can serve as an effective mechanism for sustained cooperation within the framework of international agreements on solar geoengineering. The results can be used to formulate climate change policies and agreements.