February 21, 2024

Can Solar Geoengineering be the Solution to Climate Change?

 In 2023, the U.S. government and the United Nations released reports on this controversial approach. The question of whether solar geoengineering can save the world is up for debate, and one person contributing to this conversation is Tony Harding, an assistant professor in the School of Public Policy at Georgia Tech.

Harding, an alumnus of the School of Economics, returned to Georgia Tech after completing a postdoc at Harvard University. His research focuses on the impact of innovative technology on climate change policy and governance, with a specific emphasis on solar geoengineering. Over the past eight years, he has witnessed a significant shift in the conversation surrounding this topic, particularly in terms of who is willing to engage in the dialogue.

Previously, many individuals in the climate policy and academic realms were hesitant to discuss solar geoengineering. However, Harding has noticed a change in this mindset. “There’s definitely wider acceptance of at least talking about it, and in that way, pathways to having spaces to talk about it and research funds are opening up,” he said.

The most commonly proposed method of solar geoengineering involves using sulfate aerosols, also known as solar radiation modification or climate intervention. By injecting these aerosols into the Earth’s stratosphere, they reflect a small amount of the sun’s radiation, thereby reducing the Earth’s surface temperature.

This option is the most popular and the focus of Harding’s research because it has natural examples to draw upon. “Volcanoes release sulfates when they erupt, and the largest ones are strong enough to push them into the stratosphere,” Harding explained. “So we have evidence from the past that if sulfate aerosols make it up to the stratosphere, there’s a cooling effect.” This natural analog provides some confidence that solar geoengineering could work in the real world, rather than just in theoretical models.

Researchers also consider two other types of solar geoengineering seriously: marine cloud brightening and Cirrus cloud thinning. Marine cloud brightening involves reflecting incoming sunlight by brightening marine clouds, while Cirrus cloud thinning aims to allow light to escape more easily. Each approach has its pros and cons. For instance, marine cloud brightening would primarily occur over deep ocean areas, resulting in non-uniform cooling effects and potential adverse outcomes.

On the other hand, stratospheric aerosol injection, the method Harding primarily studies, offers a more uniform distribution and cooling effect that better mimics the warming experienced on Earth. However, it comes with its own concerns, such as the temporary nature of the cooling effect. If the deployment of aerosols were to cease, whether due to political or technological reasons, the Earth would rapidly heat up, potentially leading to catastrophic consequences.

This is where Harding’s research makes a significant impact. As an economist, he analyzes the costs and benefits of solar geoengineering, highlighting the tradeoffs involved. His published articles explore how solar geoengineering may interact with other climate change mitigation policies, its potential impact on income inequality, and the value of reducing uncertainty surrounding this controversial approach.

While the debate on whether solar geoengineering can truly save the world is ongoing, Harding’s work contributes to a better understanding of this complex topic. By exploring the risks and benefits, we can make informed decisions about whether solar geoengineering is a viable solution for combating climate change.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it