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Geoengineering: Controlling Earth’s Thermostat?

Imagine being able to "reverse" climate change. What would the consequences be?

Photo credits to Pexels

Imagine living in a world where inimical chemicals constitute the air you breathe and toxic minerals stain the oceans black. This sounds like a matter of science fiction, however, these are genuine solutions proposed by scientists to mitigate climate change. In a time when carbon dioxide levels are dangerously high, desperate measures to find a solution are instinctive, but some solutions are worse than the problem. An alternative method for preserving the climate was proposed after humanity’s failure to handle the climate change crisis. These measures have influenced an impulsive need to tinker with the Earth’s thermostat. Such concept is defined as geoengineering: the deliberate large-scale manipulation of the Earth’s climate system in order to regulate climate change.

Since the dawn of the Industrial Revolution, carbon dioxide emissions have been escalating, accompanied by a rise in temperature. The current condition is 385 parts per million, just shy of the amount labeled dangerous (450 ppm). Because of this, it is crucial to demand increased action to mitigate climate change. Without a desire to alleviate the climate change crisis, sea levels will continue to rise, wildfires will continue become more prevalent, and there will continue to be health risks that come with carbon pollution affecting the lives of 7.6 billion people (10). With such an alarming future in store, different techniques to alter the climate are coming into play. Alternative methods that have increased in popularity, such as geoengineering, involve risky techniques like carbon dioxide removal and solar radiation management. These methods can be dated back to the Cold War when the Soviet Union and the United States spent extensive funds to control the weather (9).

Proposed methods to rapidly reduce atmospheric temperature involve techniques that lack empirical evidence; the two main types being carbon dioxide removal and solar radiation management. Carbon dioxide removal methods plan to reduce atmospheric carbon dioxide levels with the most common form being ocean fertilization, whereby nutrients and minerals are discharged into the upper, sunlit layers of the ocean to stimulate photosynthesis in phytoplankton (9). The latter is solar radiation management, whereby aerosols are injected into the stratosphere and mirrored shields are used to reduce incoming solar radiation. These two systems revolve around increasing the Earth’s albedo (the amount of solar energy reflected from the Earth back into space). Solar radiation management techniques involve launching billions of mirrors in orbit between the Sun and the Earth and spraying sulfur dioxide–a toxic gas and by-product of burning fossil fuels– into the stratosphere (9).

Geoengineering will undoubtedly leave an adverse impression on the environment. The reality is that the effects of aerosols on the climate is less understood than greenhouse gases. When routinely injected into the atmosphere, aerosols will increase acid deposition, contributing to ocean acidification. A study published in the Proceedings of the National Academies of Sciences labeled 55% of coral reefs as unhealthy, proving that this ecosystem could soon be nonexistent due to increasingly acidic water (1). Coral reefs are keystone environments that provide a foundation for people and animals. Although coral reefs cover less than one percent of Earth’s surface, they still support over 25% of all marine species and provide $30 billion every year in services and goods (5). The depletion of this ecosystem would undoubtedly result in destructive consequences. Furthermore, global models predict ocean fertilization efforts will ultimately turn habitable aquatic environments into anoxic marine graveyards (3). Without marine life, services normally provided by their existence such as the provision of food, medicine, and recreational activities would cease to exist. The side effects are not limited to just the environment, it also lurks to the subjects that inhabit it. Volcanic eruptions can be used as an analog for the effects of stratospheric aerosols. The eruption of the Laki fissure in 1783 released sulfate aerosols and contributed to famine in Africa, India, and Japan. Over 10,000 people died from famine and disease (9). The fallout affected a network of countries and demonstrates the complication in confining this climate engineering technique to a specific region. Overall, the employment of this rebuffed science would allow it to inundate humanity with a morbid grip.   

Propositions in favor of artificial mitigation are simply unwieldy. Geoengineering proponent and astronomer at the University of Arizona, Roger P. Angel, proposed arming a fleet of reflective disks in a stable orbit between the Earth to reduce solar radiation. However, in order to get the trillions of disks into space, it would require twenty electromagnetic launchers to fire 800,000 disks into space every five minutes (9). There would be an indisputably adverse effect on the surrounding environment from the resulting sound and gravity waves. Where would these electromagnetic launchers be placed and who would want to live nearby? This proposal is an attempt to alleviate a problem but only creates another.

Methods of artificial mitigation violate national treaties. The terms of the ENMOD (Environmental Modification) treaty, signed into accordance by the General Assembly of the United Nations, prohibits the “hostile use of environmental modification techniques” (2). Since evidence on aerosol injection techniques shows results of reduced precipitation and drought, ENMOD forbids the use of such a system. The implementation of geoengineering would also introduce skewed vulnerabilities. Since developed nations are responsible for the bulk of emissions, they will be less vulnerable. On the other hand, less-developed nations will experience the brunt of the consequences. This is exacerbated by the reality that developed nations are much more capable to bring about a solution for climate change than less-developed nations (6).

Another key issue is one of procedural justice. Operating a geoengineering system undermines the status of nations and moreover introduces a struggle for power. Who is going to be responsible for controlling Earth’s thermostat and who decides if the benefits outweigh the risks? Getting global agreement to mitigate greenhouse gases is not an easy task. The old adage “with great power comes great responsibility” serves as a motto for this issue.

Even with this last-ditch effort to revive the Earth, 10-15% of carbon dioxide will remain in the atmosphere for ten thousand years and 7% will remain for one hundred thousand years (6). During this time, carbon dioxide will continue to be released into the environment and at a theoretically faster rate. The decrease in carbon emissions will be inconsequential considering global emissions have increased by 30% over 15 years and will continue to rise with the growing population (8). This becomes a case where the dilemma is passed down to future generations, as Earth’s current subjects will not live to reap the consequences. Stephen Gardiner, professor of philosophy at the University of Colorado calls this “intergenerational buck-passing”.  

With this secondhand complication comes a staggering price tag. Relative costs are likely to be 1% or 2% of the global domestic product which is currently ~$70 trillion per year (7). That is $10-20 billion annually. It is foolish to spend so much money on a system that possesses uncertainty and risks. This immense spending could fund alternative energy initiatives instead. For instance, every house in Nebraska could be powered by photovoltaic solar panels with the annual expense on geoengineering.

The application of geoengineering techniques is a commitment of several decades. The ultimate idea is to remove an excess of harmful compounds by releasing an excess of harmful compounds. Extensive and long-term projects like this are accompanied by the possibility of human error. A striking example is the Exxon Valdez oil spill which discharged eleven million gallons of crude oil into the Prince William Sound. Exxon Valdez is the largest oil spill to date but it was confined to a certain region and measures were taken to clear up the dilemma (4). An anthropological calamity on a global level is exactly the proposition that geoengineering is offering: unlimited clearance and unpredictable outcomes. Much like the oil spill that devastated aquatic life and the pristine Arctic environment, geoengineering is a poison that will erase all life it grazes upon. If a human error can lead to such a relatively easy accident that could have been avoided, what would happen if a project with such uncertainty was employed? The consequences–known and unknown, intended and unintended–would be experienced by communities across the globe.  

The significant increase in anthropogenic emissions has prompted a need for change and a portfolio of solutions. Of these solutions, geoengineering was proposed to be a “quick-fix” to humanity’s impression on the Earth. Geoengineering slaps a band-aid on a problem that spans the globe. The climax of Earth’s temperature is strictly an anthropogenic issue; should we subject the Earth to a “Plan B”?


[1] Block, Ben. “Coral Reef Loss Suggests Global Extinction Event.” Worldwatch Institute, www.worldwatch.org/node/5960.

[2] “Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (ENMOD).” United Nations Office for Disarmament Affairs, www.un.org/disarmament/geneva/enmod/.

[3] Djoghlaf, Ahmed. “Scientific Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity.” Secretariat of the Convention on Biological Diversity, ser. 45, 2009, pp. 3–55. 45.

[4] “Exxon Valdez Spill Profile.” United States Environmental Protection Agency, www.epa.gov/emergency-response/exxon-valdez-spill-profile.

[5] Frost, Emily. “Corals and Coral Reefs.” Ocean Portal | Smithsonian, Smithsonian’s National Museum of Natural History, 30 Aug. 2016, ocean.si.edu/corals-and-coral-reefs.

[6] Gardiner, Stephen M. “Is “Arming the Future” with Geoengineering Really the Lesser Evil? Some Doubts about the Ethics of Intentionally Manipulating the Climate System.” Second Draft Version, 2010, http://folk.uio.no/gasheim/Gar2010b.pdf.

[7] “Geoengineering the Climate: science, governance, and uncertainty.” The Royal Society, 2009, https://royalsociety.org/~/media/Royal_Society_Content/policy/publications/2009/8693.pdf.

[8] Keller, David P., Feng, Ellias Y., Oschlies, Andreas. “Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario”. Nature Communications, 2014, pp. 1-11, https://www.nature.com/articles/ncomms4304.

[9] Robock, Alan. “20 Reasons Why Geoengineering May Be a Bad Idea.” 20 Reasons Why Geoengineering May Be a Bad Idea, vol. 64, no. 2, 2008, pp. 14–18-59, http://climate.envsci.rutgers.edu/pdf/20Reasons.pdf.

[10] “The Carbon Cycle : Feature Articles.” NASA, NASA. earthobservatory.nasa.gov/Features/CarbonCycle/page5.php.


Hello! My name is John Nguyen and I'm from Brevard, North Carolina, a tiny town nestled in the Blue Ridge Mountains. I'm currently a junior and I plan on majoring in Biology. Aside from STEM, I'm involved in the band as the principal bass clarinetist, baritone section leader, and drum major. I'm a student researcher, a member of NHS and AJAS, the president of InterACT, and I'm an ISEF alumnus. I'm excited to be apart of this amazing network of young scientists!

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