Geoengineering: The Best Response to Global Warming

by Jerald Lim

At a Glance:
In recent years, geoengineering has drifted away from being labelled as taboo to becoming a more viable plan in the eyes of scientists and engineers. The future of climate engineering might not be too far off; however, it currently lacks public awareness and strong governance. To succeed, it must first tackle certain legal issues and garner more public support. Advocates of it believe that, in conjunction with emissions cuts, geoengineering is our best response to climate change.

The volcanic eruption of Mount Pinatubo (Philippines) in 1991 shot almost 20 million tons of sulphur dioxide into Earth’s atmosphere. This massive dark cloud of sulphur particles blocked about 10% of the sunlight from reaching Earth’s surface, causing global temperatures to plummet by about 0.5 degrees Celsius over the course of a year [1]. Because of the sheer scale and climatic effects of the 1991 eruption, scientists view it as the foundation for geoengineering.

Meteorologists today solely rely on simulations and models and still do not comprehensively understand the workings of Earth’s climate. Because a large-scale research program on Earth’s climate could produce a plethora of negative side-effects, many consider it to be extremely unethical. Although it has garnered a small amount of support over the last decade, geoengineering research is still in the dark; and there is a lack of governance in the industry. Many scientists believe that geoengineering has the potential to be one of mankind’s most impactful scientific endeavours, but many are sceptical because of the issues it currently presents. Geoengineering does come with ethical implications and legal issues; however, public awareness and governed research can help geoengineering solve the Earth’s global warming crisis.

Figure 1: Sulphate particles blasted out of the 1991 Mount Pinatubo eruption.

The umbrella term of geoengineering, in fact, covers two completely different methods of climate engineering. The first is Solar Radiation Management (SRM), which is the spraying of sulphate aerosols into the stratosphere to create a mirror-like atmosphere that can reflect a certain amount of sunrays [2]. A total of only 1.5 million tons of sulphate aerosols per year, over the course of a few decades, would be needed to reflect sufficient amount of sunrays to curb the current rise in Earth’s temperature [3]. Though if deployed, SRM would only halt the rising global temperatures; it cannot reduce carbon concentrations in the atmosphere.

Carbon Dioxide Reduction (CDR), which is the removal of carbon dioxide from the atmosphere, could fill in the void left by SRM in a geoengineering scheme. The harvesting of carbon dioxide can take place in various ways such as: (1) Ocean fertilisation—the dumping of nutrients into oceans to increase phytoplankton production. Like plants, phytoplankton can absorb carbon dioxide from the air and carry it down to the ocean floor. (2) Ambient air capture[1], another form of CDR, is not as widely debated as ocean fertilisation; in fact, even critics of geoengineering believed that this method of CDR could be as viable as other green energy technology like the wind turbines. After harvesting carbon dioxide from the atmosphere, it can either be stored deep underground or be sold it for use in other industries. CDR costs significantly more than SRM, but with lower risks. Moreover, CDR does not just address the side-effect of carbon emissions but serves to correct the root of the problem entirely (i.e. the excess carbon dioxide in the atmosphere).

For carbon emissions to drop there is a need for reforms in the energy industry. As there is already an excess of carbon dioxide in the Earth’s atmosphere, and it cannot be effectively reduced through the naturally occurring Carbon cycle. Because of this existing carbon pollution, reforms in the energy industry without geoengineering would not prevent the increase in global temperatures. But in when implemented in conjunction with carbon emissions control, CDR and SRM will likely remove a large portion of that excess carbon dioxide in the atmosphere and cool the Earth down. For best results, geoengineering (both SRM and CDR), accompanied by emission reforms, must therefore go hand in hand in a future geoengineering project.

Figure 2: Biological and physical CO2 pumps (image source: Wikimedia)

Geoengineering poses a number of ethical issues. Can geoengineering cause more harm to humans than it does to help climate change? How far can humans tinker with nature? Like many other scientific innovations of the 21st century, geoengineering raises many of its own ethical dilemmas. In the current Anthropocene era, mankind is the main driver of environmental conditions, continuously shifting planetary climate and ecosystemic conditions, unfortunately, for the worse. With geoengineering, however, the grim fate that mankind has brought upon themselves can be delayed and hopefully be distinguished. Needless to say, geoengineering comes with its own risks, and those risks undermine the worth of a geoengineering project.

Many tremble at the thought of a geoengineering scheme failure. A sudden suspension of a geoengineering project, due to warfare, technical difficulties, or any other item on the endless list of potential hazards, would bring about a climate situation far worse than what they are today. In the graph below, all climate models support the inevitability of temperature spikes upon this possible halting of a geoengineering scheme, showing that in the two following decades after stopping, temperatures rise a colossal two degree Celsius [4]. Droughts, accompanied by mankind’s inability to adapt to the changing environment, will lead to food shortages and famines. Ice caps will melt, sea-levels will rise and the ecosystems will be threatened by the intense heat [5].

Many people also choose to oppose geoengineering for its ethical implications. Moral corruption is the “illegitimate taking advantage of a position of superior power for the sake of personal gain” [6]. Using their money, power, and fame, wealthy companies could potentially influence the direction of geoengineering research[2], but their true motive may be to prolong their businesses [7]. Geoengineering is their excuse to delay the cutting down of carbon emissions so that they can continue raking in profit.

The above situations display the false mindsets that the majority of people have on the role that geoengineering plays. They believe geoengineering is a band-aid for the world’s growing wounds. On the contrary, geoengineering cannot work successfully without global emissions cuts along with large public and governmental support. Geoengineering should not serve as a backup plan or a “plan B”; its role is to help humans get back on the right track. With the current climate fate that planet Earth is in, mankind needs to turn around, with the tools of geoengineering and emissions cuts in hand, and get not just Earth’s health back but also humanity’s conscience and humility.

Figure 3: The Carbon Cycle (image source: Wikimedia)

In order to actually get a geoengineering project up and running, all nations must come into an agreement on every aspect of geoengineering. Geoengineering does not come with the luxury of being domestic and easily controlled. One project, launched by any country in the world, would not only bring changes to its own lands and skies; the whole world gets the all the effects as well, whether it is planned or unforeseen. As a single geoengineering scheme can turn the tides on global climate situations, the world must find a compromise; and countries cannot sit out on discussions and debates on geoengineering topics. Many believed that for every country’s leaders to come to a consensus on a geoengineering scheme is quite impossible. Even if, in the slimmest of chances, theydo come to that consensus, no two countries will settle on the same specifics— global temperatures, precipitation, etc. An unagreed-on, panic geoengineering attempt would lead to war, specifically nuclear exchange, dooming Earth to a much more chilling fate.

The threat of nuclear warfare, however, entirely disregards the likelihood of a peacekeeping organisation. Without one, the globe would inevitably spiral into chaos, third-world countries wouldn’t have proper representation, and the research on geoengineering would have no governance. Geoengineering efforts must, therefore, consist of international participation–a regulatory party with delegate representing the needs of their countries. Ideally, this organisation, much like the UN, would not only keep world peace but also continuously strive for a better understanding of the effects of geoengineering on Earth’s climate.

Figure 4: Simulations of global temperatures upon deploying an SRM project (Year 0 – 50 solid line) compared to without an SRM project (Year 0-70 dotted line) and the abrupt stopping of the SRM project (at Year 50) [4].

Since the mid-2000s, the scientific community has shifted away from thinking of geoengineering as taboo, to trusting the viability of this new technology. SRM and CDR complement each other and cover up each other’s flaws. Accompanied by emission cuts, humans can reverse the climate crisis state that the world has come to. The Anthropocene era has thus far left in its wake natural disasters, destroyed ecosystems, hellish weathers, ozone depletion, ocean acidification, and many more. It is hoped that in a century or two, Earth’s climate conditions would have gone back to normal levels. Geoengineering, with the general consent of the public and with strong governance, can serve as mankind’s best response to climate change and help drive humanity back onto the right path.


[2] see, for example:


[1] Jones, Nicola. “Solar Geoengineering: Weighing  Costs of Blocking the Sun’s Rays.”

Environment 360, Yale University, 9 Jan. 2014, Accessed 4 Sept. 2016.

[2] “What Is SRM.” SRMGI, Accessed 3 Oct. 2016.

[3] Reebs, Stéphan. “Sulfur Spritzer.” Natural History, vol. 117, no. 4, May 2008, p. 14. History Reference Center, Accessed 31 Aug. 2016.

[4] Jones, Andy, et al. Figure 1. Evolution of annual mean anomaly of global mean near-surface air temperature (K) in the G2 simulations (solid lines) with respect to the long-term mean from each model’s CMIP5 piControl simulation. Timeseries from corresponding 1pctCO2 simulations are also shown (dotted lines). The termination of geoengineering in the G2 simulations is indicated by the dashed vertical line. PDF file, 11 Sept. 2013. Chart.

[5] Plumer, Brad. “Once You Start, You Can’t Really Stop.” The Washington Post, 2 Jan. 2014. Accessed 12 Oct. 2016.

[6] Gardiner, Stephen M. A Perfect Moral Storm: The Ethical Tragedy of Climate Change. New York, Oxford UP, 2011.

[7] Preston, Christopher. “Ethics of Geoengineering Intro.” University of Montana. Accessed 19 Sept. 2016.

About the Author

JERALD LIM is a young but curious mind in a world of growing technological and scientific development. Although currently only a senior high-schooler in Penang, he believes that one day his voice will be heard around the world. Ever since a young age, he has been fascinated by the wonders of science, from the miniscule miracles of an atom to the immense scale of the universe. Accompanying his love for science is his passion for Earth and solving its most pressing issues. He hopes that his addition into the world scientific research will help the world become a brighter place. To find out more about the author, visit his SciMy profile at