The ethics of geoengineering is a very interesting topic that is becoming more and more pertinent to the present day. We currently have, and are, improving and developing technology that is capable of controlling climate change. Whether this be through injecting sulfur into the atmosphere or by large scale carbon capture, technologies like this are on the horizon (we actually have the capability of offsetting our emissions through carbon capture today, but it would cost an estimated $6.3 and $15 trillion annually to do so. For reference the GDP of the USA was $18.14 trillion in 2018 ).
In her article “Geoengineering and Sustainability”, Leslie Paul Thiele tackles the debate as to whether or not we should undertake geoengineering . She splits up the debate into two belief systems, the Prometheans and Gaians. The Gaians believe that humanity will never have power over nature to successfully pull off geoengineering. They believe that even if we do alter the planet in a major way, there will always be severe consequences and nature will have the final say. On the other hand, Prometheans hold the viewpoint that we, as humans, have always been distinguished by our technology and we have been geoengineering (on smaller scales) since we started using tools and fire to shape our surroundings. This viewpoint holds the idea that humanity has the power to successfully geoengineer the planet. However, this is only true if the risks and rewards of a given technology reach the point that it is logically considered feasible. She then goes on to assert that the only way to bring these viewpoints together is through the lens of sustainability.
I agree that sustainability is a powerful, uniting framework that can unite both of these world views. However, I would assert that the issue is more complex. Splitting people up into two groups, the Prometheans and Gaians, is an oversimplification of humanity. People fall on a spectrum of belief and worldviews that cannot be cleanly split into two camps. I agree though that the concept of sustainability can bring people together for a common good. Making sure that we treasure our planet and ensure it will be livable and thriving for future generations to come is a key, uniting factor for all people. Through this viewpoint, whether geoengineering is a part of our future or not, it is definitely worth keeping on the table.
Humanity is at a crossroads where our power as a species is changing to a larger scale. We are transitioning to the point where our technology is capable of impacting the entire planet, whether we like it or not. As John Green puts it in his book The Anthropocene Reviewed, “We are at once far too powerful and not powerful enough… [being able] to radically reshape the Earth’s climate and biodiversity but not powerful enough to choose how we reshape it.” 
 Ritchie, Hannah, et al. “What Can You Do to Stop Climate Change? And Should You?” Kurzgesagt – In a Nutshell , Kurzgesagt, 22 Sept. 2021, https://www.youtube.com/watch?v=yiw6_JakZFc.
 Leslie Paul Thiele (2019) Geoengineering and sustainability, Environmental Politics, 28:3, 460-479, DOI: 10.1080/09644016.2018.1449602
 Green, John. The Anthropocene Reviewed: Essays on a Human-Centered Planet. Dutton, 2021.