Solar geoengineering: A new tool for fighting climate change

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OCTOBER 5, 2022 — Editor’s note: This op-ed by Hamid Beladi, Janey S. Briscoe Endowed Chair in Business in the Carlos Alvarez College of Business and Amitrajeet A. Batabya, Arthur J. Gosnell professor of economics at the Rochester Institute of Technology originally appeared in the San Antonio Express-News.

Scientists, economists and policymakers throughout the world now agree that climate change is the most serious environmental problem confronting humankind today. Although the long-term changes in temperatures and weather patterns that we are talking about are caused, at least to some extent, by natural forces, there is consensus today that at least since the 1800s, human activities have been the primary factor in making climate change the salient problem that it is today.

Burning fossil fuels — examples include coal, oil, and gas — is the main human activity that has contributed to the rise in the Earth’s surface temperature. This generates emissions of greenhouse gases such as carbon dioxide and methane. Metaphorically speaking, these emissions can be thought of as a blanket that wraps planet Earth, traps the sun’s heat and raises the Earth’s surface temperature.

To address this problem, economists and policymakers have generally advocated the use of price (tax) and quantity control (carbon credits) instruments. Efforts have largely been concentrated on creating the right incentives to get people and firms to diminish their use of fossil fuels and move toward renewable energy sources. Occasionally, politicians have even advocated the use of bans to alter human behavior. For instance, California Governor Gavin Newsom recently stated that by 2035, his state would ban the sales of new gasoline powered cars and light trucks. The hope here is that such an act will provide a forceful nudge to state residents to drive more electric vehicles that typically have no tailpipe emissions.

Although there is nothing wrong with using price and quantity control instruments to fight climate change, these traditional tools have not done enough to put a dent in the massive problem that confronts us. We seem to hear and see stories about climate devastation almost regularly. In recent times, there have been multiple news reports about record high temperatures in the western states of the U.S., devastating floods in multiple cities in Australia and in large parts of Europe including Germany and the Netherlands, unbearable heatwaves in New Delhi, India, and uncharacteristically high rainfall leading to extensive flooding in Pakistan.

It's time to think of new solutions to fight climate change. This means thinking seriously about solar geoengineering or climate engineering. This kind of engineering encompasses two kinds of technologies: carbon dioxide removal and, most intriguingly, sunlight reflection methods.

Carbon dioxide removal technologies refer to processes such as direct air capture that attempt to deal with a key cause of climate change by lowering atmospheric carbon dioxide concentrations. However, as Cornell University researcher Doug MacMartin and his colleagues have pointed out in research published in the Proceedings of the National Academy of Sciences, present strategies for carbon dioxide removal are either not at scale or are too expensive to meaningfully reduce the 40 billion tons of carbon dioxide emitted by humans each year.

This saturnine perspective on direct air capture brings us to solar radiation modification, which is possibly a worthwhile climate change mitigation strategy. The relevant technology involves injecting sulfate aerosols into the stratosphere so that more sunlight bounces off the Earth’s atmosphere instead of being absorbed by the earth with its “blanket covering.” The basic point is that sunlight reflection methods, including stratospheric aerosol injection, can compensate for the negative effects of climate change by cooling planet Earth.

Climate engineering is a fascinating new area of research and, admittedly, we do not know all the effects that might arise were we to employ the technologies suggested by this new research. Although we can continue to use price and quantity control instruments to fight climate change, two points are key. First, society must seriously think about expanding its policy toolkit with promising approaches. Second, it must explore all available options to identify the best opportunities to make our planet more hospitable for generations to come.

— Hamid Beladi and Amitrajeet A. Batabyal

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