The time has come for governments to start thinking outside of the box when it comes to abnormally warm temperatures across the globe. Leading scientists have confidence in a potential solution: the future application of solar geoengineering. A team of aeronautical engineers, led by Yale Professor Wake Smith, recently released a new report concerning discoveries about sulfur injection applicability. Sulfur injection is a form of solar geoengineering, involving dispersal of particles that reflect sunlight back toward space, instead of letting the sun’s rays heat Earth.
The scientists found that sulfur dispersal will be substantially more effective at altitudes of 25 km above sea level, which is five kilometers higher than the level initially agreed upon by scientists (Smith 2022). To put this altitude into perspective, airlines and military planes fly at 10 km, while elite spy planes fly at about 20 km (Institute of Physics 2022). Instead of using the originally intended baseline aircraft, called Stratospheric Aerosol Injection Lofter (SAIL-01), the aeronautical engineers constructed five different aircraft options capable of flying at these extreme altitudes (Smith 2022). As experts dedicate their resources and energy toward developing optimal solar geoengineering methods, governments should familiarize themselves with the possible innovations.
Warming Up to Cooling the Planet
Climate change discussions often revolve around emissions reduction and renewable energy solutions, and do not adequately address temperature reduction strategies to restore a cooler climate. The global community must, of course, first reach the goals of net zero emissions and keeping temperature increases below 1.5℃. But even if policymakers and scientists achieve this objective, populations around the world will continue to see the consequences of abnormally hot weather. In other words, this objective will result in halting temperature increases, while allowing already high temperatures to remain. Striving for global cooling has the potential to more effectively eliminate some of the worst consequences of climate change.
Achieving net zero emissions will finally put an end to further temperature increases. The negative effects of already hot temperatures, on the other hand, will remain with us for generations to come and will especially impact poor populations. Scientists from Stanford University explain that warming temperatures cause GDP to decrease in warm countries and increase in cooler countries (Diffenbaugh 2019). Poor countries are most often located in these hot climates, meaning climate change issues also become social justice problems. These temperature increases contribute to decreased mental and physical productivity, making economic expansion a far steeper hill to climb than in countries with moderate temperatures (Keith 2021). Although considerations to eliminate emissions and halt global warming remain at the forefront of science and policy regarding climate change, these objectives must also aim to cool our already hot climate.
How Can We Cool the Planet?
Currently, there are only two major cooling solutions, both of which are forms of climate intervention technologies, or geoengineering. These two methods include carbon capture technologies, which also include natural tools for carbon capture such as plants, and solar geoengineering. Especially when regarded as a collaborative force, both hold significant potential for restoring a cooler climate.
Figure 1. Here is an illustration of various geoengineering projects. It includes both carbon capture technologies and solar geoengineering methods to provide a visualization of the variety of forms geoengineering can encompass.
(Bhatt 2019)
Strengths and Weaknesses: Carbon Capture Technologies
Carbon capture and storage technologies receive the greatest amount of attention from environmentalists, policymakers, and industry (Keith 2021). The process of carbon capture involves the removal of CO2 from the atmosphere, followed by either immediate use, transport for future use, or injection into the ground (IEA 2021). These technologies have already seen actualizations. For example, over 100 new facilities for carbon capture, utilization, and storage (CCUS) were announced in 2021 (IEA 2022). In addition, carbon capture technologies can be implemented on a grand-scale with long-term utilization potential. With all of this promise and development, where is the need to look into other climate intervention technologies?
Doubts surrounding carbon capture’s short term effectiveness and less-than-desirable consequences leave room to explore other options. Carbon capture technologies can hinder the normal functioning of ecosystems, harming marginalized communities (Keith 2021). This phenomenon comes into play with forms of carbon capture that rely on modifying natural processes. For instance, trees and other plants suck carbon from the atmosphere, but they have limitations. Genetic modifications can make these plants more sturdy and better equipped to handle threats such as root rot. They do, however, disrupt natural ecosystems. Irrigation and fire prevention are additional aspects of certain carbon capture techniques that disrupt natural ecosystems. The human communities that thrive on these ecosystems are, therefore, put at a disadvantage. Furthermore, the construction and operation of industrial carbon capture facilities rely on a substantial amount of resources including energy, steel, and cement (Keith 2021). While carbon removal has already proven its effectiveness in emission reduction and subsequent cooling, it does have social and environmental downfalls. Investments in solar geoengineering in conjunction with carbon capture can help to rectify some of these disadvantages.
Solar Geoengineering
Studies show that a collaborative approach could allow some solar geoengineering methods to make up for shortcomings in carbon capture technologies. Solar geoengineering strategies in academic discussion today include the dispersal of sulfuric acid particles in the stratosphere, whitening clouds near the ocean with sea salt spray, and eliminating high altitude clouds that trap heat in the atmosphere (National Academies 2021). The particle injection theory, that is a huge component of the discussion today, involves dispersal of two million tons of sulfur into the atmosphere to reflect sunlight back toward the sun (Keith 2021). And, unlike carbon capture, these technologies are effective on short timelines, making solar geoengineering a cheaper option.
Like carbon capture, solar geoengineering also comes with controversies. One concern with solar geoengineering is determining which countries have jurisdiction over implementing these innovations. Solar geoengineering requires incredibly expansive, planetary scale implementation, which will result in widespread effects. An international organization is, therefore, necessary to designate the roles of certain countries as leaders in solar geoengineering (Keith 2021). This organization could also help countries come to agreements concerning other issues involving solar geoengineering. Additional considerations include the anticipated length of time to utilize these technologies (Keith 2021), unintended consequences (Frumhoff 2018), and a lack of legitimacy given by the international community to solar geoengineering.
Although solar geoengineering is controversial, it is not a random shot in the dark as scientists scramble to solve increasingly hot climates. Rather, these technologies are founded in natural processes, especially based on volcanic eruptions (Reynolds). While it may appear frightening to simulate a volcanic eruption by spraying two million tons of sulfur into the atmosphere, it is actually only about one twentieth of current annual sulfur pollution produced by fossil fuels (Keith 2021). Solar geoengineering looks very promising, but respected international organizations must first accept and adopt it before policymakers are likely to agree to its implementation.
Let’s Cool the Debate: Keep Solar Geoengineering in the Conversation
The extensive research and modeling behind solar geoengineering, such as the investigation by Professor Smith and his team, into the most effective form of sulfur injection technologies, make it an ideal option for investment by policymakers. Solar geoengineering can contribute to cooling the climate and reducing the consequences of global warming, specifically aiding poor countries with hot climates. But, the UN has eliminated the inclusion of solar geoengineering from their suggestions to policymakers (Keith 2021). They are afraid of taking too large of a gamble. In reality, they are taking a greater gamble by failing to recognize the scientists who recommend solar geoengineering technologies. By including these technologies as part of the solution to climate change, the UN maintains the option to lower excessively high temperatures, aiding the most helpless and negatively affected countries. Let’s cool it: both the debate of solar geoengineering’s potential and the planet.
