Geoengineering: An Efficient Method of Climate Change Mitigation or a Future Global Catastrophe?

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SRM could theoretically be executed by using specially equipped planes flying at high altitudes and releasing sulfuric acid into the stratosphere

Climate change is widely perceived as an existential threat to global biodiversity and to the human race itself. New climate modeling consistently suggests that without enormous, rapid changes to the carbon-based world energy infrastructure, there will be vast temperature increases coupled with devastating environmental effects around the world. The lack of an international political will to transition away from the status quo fast enough means that the worst case scenarios found in climate models are increasingly likely. In the face of this crisis, many have voiced a faith in the capacity of science to develop new solutions to overcome climate change without any sacrifice on the part of world governments and citizens. One idea that has gained traction in recent years as a relatively easy solution (compared to massive reductions in carbon emissions) is geoengineering. This can take many forms, but for the purposes of this piece I will focus my discussion on the most researched method: seeding the stratosphere with sulfuric acid to increase the amount of sunlight reflected away from the Earth.

The argument for the efficacy of this technique is grounded in historical data from volcanic eruptions that naturally filled the upper atmosphere with sulfuric acid and reduced global temperatures for a time. “Natural experiments” such as the eruption of Mt. Pinatubo in the Philippines in 2001 showed that the massive influx of aerosols into the stratosphere from the event decreased global temperatures by about 1 degree Fahrenheit for around 2 years. Importantly, however, at this stage there have been no large scale experiments executed by scientists to test the effects of solar radiation management (SRM), not least because taking these first steps involves  essentially untested and potentially dangerous technologies. The trusted method of scientists remains large scale cutbacks of greenhouse gas emissions. But as temperatures continue to rise and far from sufficient action has been taken to reduce global emissions, it is worth examining the potential benefits and pitfalls of geoengineering as a last ditch solution.

SRM could theoretically be executed by using specially equipped planes flying at high altitudes and releasing sulfuric acid into the stratosphere. The primary advantage of such a procedure is that it could provide humanity with necessary time to cut back on greenhouse gas emissions without temperatures rising during that period. In the best case scenario, the usage of sulfuric acid could gradually decline over time along with falling carbon emissions until both reach 0. At that point the world’s temperature would not have risen to catastrophic levels, and global ecosystems could begin a process of recovery. Thus, used correctly, SRM could be a key tool to give humanity enough time to transition into renewable energies and a zero-emission economy while delaying climate devastation long enough to prepare mitigation procedures.

However, this best case scenario is not without risk. One of the most significant potential risks of utilizing SRM is that the momentary reprieve from climate change would reduce motivation for the more important efforts at transitioning to green energy. In this case, a false confidence could lead to inaction and a growing dependence on increasing amounts of sulfuric acid use to counteract climate change. If carbon emissions were not cut drastically, when the use of SRM stopped a catastrophic temperature increase would occur. The rapidity of this change in climate would be so intense due to its delayed nature that it would essentially destroy all the world’s ecosystems and lead to massive loss of life.

The speed of this change would make it much more severe than the relatively more gradual increase in climate occurring naturally. Even if this worst-case scenario did not occur, there are other dangerous risks with the use of SRM. For example, rainfall fell in areas around the world after the eruption of Mt. Pinatubo. Other devastating changes in weather patterns and global climate are possible, given our lack of knowledge about the use of SRM.

Ultimately, given the severe risks and massive uncertainty of SRM, its use should rightly only be considered a last resort. The hesitancy of scientists to even consider experimentation demonstrates the justifiable fears of a societal dependence on SRMClimate change is widely perceived as an existential threat to global biodiversity and to the human race itself. New climate modeling consistently suggests that without enormous, rapid changes to the carbon-based world energy infrastructure, there will be vast temperature increases coupled with devastating environmental effects around the world[1]. The lack of an international political will to transition away from the status quo fast enough means that the worst case scenarios found in climate models are increasingly likely[2]. In the face of this crisis, many have voiced a faith in the capacity of science to develop new solutions to overcome climate change without any sacrifice on the part of world governments and citizens. One idea that has gained traction in recent years as a relatively easy solution (compared to massive reductions in carbon emissions) is geoengineering. This can take many forms, but for the purposes of this piece I will focus my discussion on the most researched method: seeding the stratosphere with sulfuric acid to increase the amount of sunlight reflected away from the Earth.

The argument for the efficacy of this technique is grounded in historical data from volcanic eruptions that naturally filled the upper atmosphere with sulfuric acid and reduced global temperatures for a time. “Natural experiments” such as the eruption of Mt. Pinatubo in the Philippines in 2001 showed that the massive influx of aerosols into the stratosphere from the event decreased global temperatures by about 1 degree Fahrenheit for around 2 years[3]. Importantly, however, at this stage there have been no large scale experiments executed by scientists to test the effects of solar radiation management (SRM), not least because taking these first steps involves  essentially untested and potentially dangerous technologies[4]. The trusted method of scientists remains large scale cutbacks of greenhouse gas emissions. But as temperatures continue to rise and far from sufficient action has been taken to reduce global emissions, it is worth examining the potential benefits and pitfalls of geoengineering as a last ditch solution.

SRM could theoretically be executed by using specially equipped planes flying at high altitudes and releasing sulfuric acid into the stratosphere. The primary advantage of such a procedure is that it could provide humanity with necessary time to cut back on greenhouse gas emissions without temperatures rising during that period. In the best case scenario, the usage of sulfuric acid could gradually decline over time along with falling carbon emissions until both reach 0. At that point the world’s temperature would not have risen to catastrophic levels, and global ecosystems could begin a process of recovery[5]. Thus, used correctly, SRM could be a key tool to give humanity enough time to transition into renewable energies and a zero-emission economy while delaying climate devastation long enough to prepare mitigation procedures.

However, this best case scenario is not without risk. One of the most significant potential risks of utilizing SRM is that the momentary reprieve from climate change would reduce motivation for the more important efforts at transitioning to green energy. In this case, a false confidence could lead to inaction and a growing dependence on increasing amounts of sulfuric acid use to counteract climate change. If carbon emissions were not cut drastically, when the use of SRM stopped a catastrophic temperature increase would occur. The rapidity of this change in climate would be so intense due to its delayed nature that it would essentially destroy all the world’s ecosystems and lead to massive loss of life.

The speed of this change would make it much more severe than the relatively more gradual increase in climate occurring naturally. Even if this worst-case scenario did not occur, there are other dangerous risks with the use of SRM. For example, rainfall fell in areas around the world after the eruption of Mt. Pinatubo. Other devastating changes in weather patterns and global climate are possible, given our lack of knowledge about the use of SRM.

Ultimately, given the severe risks and massive uncertainty of SRM, its use should rightly only be considered a last resort. The hesitancy of scientists to even consider experimentation demonstrates the justifiable fears of a societal dependence on SRM. At its best, the utilization of sulfuric acid in the stratosphere to reflect greater quantities of solar radiation would only delay the onset of temperature rises and severe weather effects due to greenhouse gas emissions. This could provide essential time for the world to reduce emissions and transition into a clean energy economy. However, the use of SRM provides the dual risk of dependence on it that could unpredictably damage the world’s climate and lead to an unstoppable, rapid rise in temperature after the use came to an end. If we are forced to utilize SRM, it should be in conjunction with massive cuts to carbon emissions and similar reductions to sulfuric acid placed in the atmosphere to avoid dependence on SRM or a massive temperature rise from a sudden stoppage. The riskiness of SRM should remind us that there is no silver bullet to stopping climate change: innovative ideas like geoengineering must not distract the public from the reality that reducing carbon emissions is the only genuine solution to climate change.



[1]https://www.vice.com/en/article/9393jd/climate-change-predictions-have-suddenly-gone-catastrophic-this-is-why

[2]https://environmentjournal.online/articles/is-it-too-late-to-stop-climate-change/

[3]https://earthobservatory.nasa.gov/images/1510/global-effects-of-mount-pinatubo

[4]https://www.technologyreview.com/2013/02/08/84239/a-cheap-and-easy-plan-to-stop-global-warming/

[5] https://royalsocietypublishing.org/doi/10.1098/rspa.2019.0255

More posts by Elliott Hyman.
Geoengineering: An Efficient Method of Climate Change Mitigation or a Future Global Catastrophe?
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