Solar Geoengineering: Fact or Science Fiction?

By Angela Zhong


It is well documented that climate change affects societal agricultural productivity, energy use, and even crime in the United States alone. While politicians are criticized for their cosmetic reforms, the economic research in this field has grown hazier with denialism. Pearce, however, challenges the fundamental assumptions behind status quo efforts. He explains from the climate assessment by the Intergovernmental Panel on Climate Change (IPCC), “CO2-induced warming is projected to remain approximately constant for many centuries following a complete cessation of emission.“ Maintaining the status quo, therefore, is insufficient to truly resolve the large-scale impacts of warming. Instead, policymakers and the general public need to actively investigate options within the growing field of geoengineering and climate engineering.


While this conclusion may seem intuitive to some, the concentration on climate engineering is crucial -- many modern proposals are primarily focused on stalling the rate of greenhouse gas emissions. These deflationary methods are numerous, complex, and competing. Debates about carbon pricing rage onwards. This set of conflicting opinions is particularly challenging for policymakers, many with only a layperson's understanding, to decide on the optimal approach for constituents and the world writ-large. Narrowing the focus from thousands of choices to a handful circumvents the paralyzing paradox of choice so that they can center on pushing forward actual change.

The complexities of climate reform apply to geoengineering as well. Within this specific study, there are many solutions to target different aspects of the problem with the two largest classes being Solar Radiation Management (SRM) and Carbon Dioxide Removal (CDR), also known as Greenhouse Gas Removal (GGR). For brevity, this article will primarily advocate for the former. As the name suggests, SRM solutions aim to reflect a portion of the sun’s radiation back into space, thereby reducing the amount of solar radiation trapped in Earth’s atmosphere. Popular methodologies for SRM include but are not limited to installing reflective surfaces or increasing albedo, such as stratospheric sulfate injection or marine cloud whitening.


Moreno‐Cruz and Keith identify that solar geoengineering is different from traditional mitigation in two key ways: it is inexpensive and immediate. Assuming that countries can repurpose existing capital such as planes, the costs of injecting 1 TgS of a sulfur gas per year into the stratosphere is only an estimated 0.225–30 billion dollars according to Robock, Royal Society, and many others. This may seem like a large number to the average person initially, but is far cheaper than other aforementioned solutions. There are a multitude of benefits to this. First, if SRM turns out not to be as effective as projected, there is a low cost to ending the project and thus, there is likely to be more support. Second, Harding argues that the relatively low cost is able to minimize, if not effectively eliminate, the free-riding problem where one country’s initiative will benefit others at next to no cost. Blackstone and Long continue this latter line of thinking to deduce that large-scale environmental decisions need not be constrained by the logic of multilateralism any longer, resolving yet another economic problem. Because influential actors do not have to mobilize and coordinate with other states to make a change, it is more likely that they are able to take action on this untouched subject.


Additionally, SRM has the added net benefit of addressing the disproportionate impact that climate change has on developing nations; utilizing a state-of-the-art macroeconomic climate impacts assessment approach based on the projected impact of SRM, Ricke concludes that the global cooling would increase the GDP and average income of Niger, Chad and Mali by more than 100 percent over the course of the century in comparison to their current trajectory. This is a notable contrast to the U.S. and Southern Europe’s 20 percent growth though, admittedly, more analyses should be conducted to verify this model. (Many quantitative analyses of SRM adapted integrated assessment models, IAM, to produce the popular dynamic integrated climate‐economy model, also dubbed “DICE,” originally developed by Nordhaus.)

My advocacy for geoengineering is, however, not mutually exclusive with other initiatives and should not be an excuse or economic substitute for appeals for mitigation. Instead, I hope this article can shed light from a complementary angle in which to research nascent solutions and achieve a common goal of minimizing anthropogenic climate change. Proposals from “science fiction” should no longer be brushed aside but utilized to arm future generations with what can be. Politicians need to open their worldview and take a stance for the advancement of science. Even through the introduction of bills, we can bring SRM into public discourse as a viable option.