Skip to main content

Solar geoengineering: A source to slow down climate change

June 28, 2019


Vanessa Wong

As human activities continue to develop, Earth’s climate is changing faster than ever before. The temperatures of Earth’s surface continue to rise, and emissions of heat-trapping greenhouse gases are a primary cause of climate change. In the Arctic, the increased temperatures reduce the extent of highly reflective sea ice and snow, which leads to the increase in absorption of energy at the surface, thus creating a positive feedback loop. The melting of ice in the Arctic significantly affects the Indigenous population. Climate change is causing Indigenous peoples to lose land and natural resources that are crucial to their subsistence lifestyle. It is causing Arctic Indigenous groups such as the Chukchi, Inuit and Sami to suffer local impacts to their activities such as whaling, fishing, sealing and reindeer herding. This melting of ice greatly affects the Inuit’s land, making hunting, fishing and travel in the Arctic more difficult, even forcing members to relocate after flooding.

As a possible solution to the heating of the planet, geoengineering is an environmental process that affects Earth’s climate. Geoengineering is a term used to describe large scale, targeted intervention in the Earth’s atmosphere, the oceans and the biosphere. Geoengineering proposals began in the middle of the 20th century and are to alter weather systems to create favorable climate conditions on regional scales. There are two broad categories of the manipulation process: carbon geoengineering and solar geoengineering. Carbon geoengineering, also known as carbon dioxide removal (CDR), is an approach that would extract carbon dioxide from other gases in the atmosphere and store it in the ocean or underground. Solar geoengineering, also known as solar radiation management (SRM), seeks to reflect small fractions of sunlight back into space through the injection of sulfur particles into the stratosphere, the whitening of marine clouds and the delivery of tiny orbital mirrors into space. As opposed to carbon geoengineering, solar geoengineering does not serve as a solution to the root cause of climate change, but instead as a temporary response to climate change. Climate change plays a major role in the lives of the Indigenous people and forces them to change life habits and their methods of survival. This method aims to slow the process of climate change to help the Indigenous people adapt to those changes of lifestyle, while other methods develop to stop climate change. What are solar radiation management techniques that can offset climate change? And are they worth the potential effects it may have on the environment? This brief will share two major ideas surrounding solar geoengineering that can play a role in balancing the impacts of climate change.

Pre-Existing Policy

There is currently research projects regarding the approaches to solar radiation management, three of which are open-air experiments planned in the United States and in Indigenous territories. There are no current policies or international laws regarding geoengineering; however, efforts to promote carbon capture and storage are widespread. Many states have created agreements that are relevant in relation to geoengineering, including the Convention on Long-range Transboundary Air Pollution, which deals with sulphur emissions. The parties of the 1996 Protocol of the London Dumping Convention (LC/LP) and the Convention on Biological Diversity have addressed geoengineering, focusing on ocean fertilization and further research into such methods.

Policy Options

This brief will focus on solar radiation management projects. SRM projects should be the initial approach due to its lower costs, relatively readiness for deployment and its lower chances of risk. It is used as a means to buy time for society to develop more effective ways to reduce greenhouse gas emissions. The following will discuss two efficient methods: stratospheric aerosol injections and marine cloud whitening.

  1. Stratospheric Aerosol Injection

Climate change is largely due to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels, also referred to as the greenhouse effect. The energy and heat that radiates back to the planet from the atmospheric greenhouse gases heat both the lower atmosphere and the surface, causing the planet to continuously get warmer. The process of sulfur particles in solar geoengineering aims to limit the effect of climate change due to rising levels of greenhouse gases. The delivery of precursor sulfide gases such as sulfuric acid, hydrogen sulfide or sulfur dioxide is released by artillery, aircraft and balloons into the stratosphere to act as a reflector of sunlight. These methods have proven to be the most rapid and would have the lowest direct costs. This delivery mimics a natural volcano eruption, as the small ash and aerosol particles that are erupted decrease the amount of sunlight reaching the surface of the Earth. Much of the technology required is pre-existing, such as the chemical manufacturing, artillery shells, weather balloons, high-altitude aircrafts and so on. In addition, stratospheric aerosol injection (SAI) would cost much less in comparison to other methods of intervention.

Possible side effects of SAI are ozone depletion, regional warming, and health effects. In addition to ozone depletion, stopping SAI once it has begun can become extremely dangerous, as there would be a rapid temperature and precipitation increase at 5-10 times the rates from gradual global warming. Research has suggested that targeting geoengineering in one hemisphere would have catastrophic effects in other hemispheres, particularly those prone to storms or droughts. A solution to such a danger would be to ensure that programs are collaborating with each other. Any unilateral geoengineering programs must be tightly regulated.

  1. Marine Cloud Whitening

The geoengineering technique of cloud whitening is to increase the reflectance of Earth’s cloud cover to reduce the amount of solar radiation striking Earth’s surface. The goal is to increase the Earth’s albedo, in order to reduce the heating of the planet. Due to lower levels of dust and pollution over the ocean, the marine environment has a deficit of cloud condensation, therefor marine cloud brightening would be most effective over the ocean as opposed to over land. Spraying devices placed on land and ships traversing the ocean would deliver a fine mist of salt from seawater into banks of marine clouds over the ocean. The water droplets evaporate, and bright crystals would remain to reflect incoming solar radiation back into space. In addition, they can serve as condensation nuclei and form new water droplets, increasing overall marine cloud coverage, and reflecting more solar radiation back into space. A strength of marine cloud brightening is that it can be gradually scaled, and results are easier to be recorded and tracked. With the low cost of Solar Radiation Management, single states or a few nations working together could attempt to halt warming, and should any negative outcome be created, the technique could be stopped very rapidly.

Currently, there have not been any experiments conducted with this technology. Similar to stratospheric aerosol injections, cloud whitening is a project that cannot be done unilaterally. Doing so would raise risk for other regions and could cause disastrous environmental effects, one of which is the possible lessening of rainfall.

Policy Implications and Recommendations

Every day, the lives of Indigenous peoples and individuals in the Arctic are affected by climate change. The warming of Earth’s temperatures has led to the melting of ice, shorter winters, change in biodiversity, and as a result has drastically changed the lives of the Arctic population. The estimated thinning rate of the ice cover of 4 centimeters per year can mean that the Arctic Ocean could potentially be ice-free in the next 50 years. Since the 1950s, the Arctic Ocean has been retreating at a rate of 2.8-4.3% per decade. However, the annual-average rate increased to 10.7% per decade beginning in 1996. Indigenous peoples are one of the first populations to face direct consequences of climate change due to their dependence and close relationship with the environment. Their dependence on hunting for walrus, polar bears, seals and caribou and fishing are their means of supporting the local economy and is the basis for their cultural identity. Climate change has played a role in changing the species and the availability of traditional food sources as well as reduced safety in traveling due to the changes in weather and ice.

Geoengineering aims to slow down the processes of global warming, preventing the effects of climate change from developing so rapidly. Indigenous peoples have had to adapt drastically over the years to the continuous impacts of climate change, and the implementation of solar geoengineering aims to slow down the process and allow for the development of processes that can allow Indigenous people to adapt and potentially resume their traditional lifestyles.


Along with the development of dependence on industrial activities and human development, climate change will continue to be a growing issue. Both stratospheric aerosol injections and marine cloud whitening are starting projects to put a halt on the warming of the planet and allow for more time to develop solutions to the continuous problem of climate change8. They are low cost projects that do not require much additional technological developments and could be implemented soon. A large obstacle that both projects face is the collaboration among regions and nations must ensure that there is consistency across the planet, to avoid negative effects in other regions. Although the projects contain risks, this prospect would be a large step towards combating climate change, and a start to potential developments to reduce damage on our environment.



Abate, Randall S., and Elizabeth Ann Kronk. “Commonality Among Unique Indigenous Communities: An Introduction to Climate Change and Its Impacts on Indigenous Peoples.” Tulane Environmental Law Journal, vol. 26, no. 2, 2013, pp. 179–195. JSTOR,

Bickel, J Eric, and Lee Lane. “Definition And Description Of SRM Solutions.” Copenhagen Consensus Center, 2018, pp. 14–28, An Analysis of Climate Engineering as a Response to Climate Change,

Burns, William C.G. “Overview of Climate Geoengineering.” C. Hurst and; Company, 2016, pp. 3–17, The Paris Agreement and Climate Geoengineering Governance: The Need For A Human Rights-Based Component,

Johannessen, Ola M., and Martin W. Miles. “Arctic Sea Ice and Climate Change — Will the Ice Disappear in This Century?” Science Progress (1933- ), vol. 83, no. 3, 2000, pp. 209–222. JSTOR,

Keith, David W. “Toward a Responsible Solar Geoengineering Research Program.” Issues in Science and Technology, vol. 33, no. 3, 2017, pp. 71–77. JSTOR,

Kuokkanen, Tuomas, and Yulia Yamineva. “Regulating Geoengineering in International Environmental Law.” Carbon & Climate Law Review, vol. 7, no. 3, 2013, pp. 161–167. JSTOR,

Lane, Lee, et al. “Solar Radiation Management And Rethinking The Goals Of Cop-15.” Copenhagen Consensus Center, 2009, pp. 15–24, Advice For Policymakers,

Leal-Arcas, Rafael, and Andrew Filis-Yelaghotis. “Geoengineering a Future for Humankind: Some Technical and Ethical Considerations.” Carbon & Climate Law Review, vol. 6, no. 2, 2012, pp. 128–148. JSTOR,

Wadhams, Peter. “Arctic Ice Cover, Ice Thickness and Tipping Points.” Ambio, vol. 41, no. 1, 2012, pp. 23–33. JSTOR,

Whitten, Robert C. “Greenhouse Gases and Global Warming.” Naval War College Review, vol. 56, no. 1, 2003, pp. 142–145. JSTOR,