The phenomenon that we now call climate change refers to long-term changes in temperatures and weather patterns. Although, in principle, these changes can be natural, the scientific consensus today is that human activities have been the principal driver of climate change since at least the early 100s.
The specific human activities that have exacerbated the climate change problem have everything to do with burning fossil fuels such as coal, oil and gas. Specifically, the problem when we burn fossil fuels is that this activity gives rise to emissions of greenhouse gases such as carbon dioxide and methane. These emissions act like a blanket that wraps planet Earth and thereby traps the sun’s heat and raises the surface temperature.
To address this problem, which is certainly the most salient environmental problem that confronts humans today, we have generally been thinking inside the box. This means that our efforts have largely been focused on creating incentives and setting policies to get people and firms to reduce and ideally eliminate their use of fossil fuels and move towards renewable energy sources. A good example of such a policy is the provision of tax breaks to those who switch from gasoline powered to electric vehicles. In this regard, California recently announced that by 2035, the state would ban the sales of new gasoline powered cars and light trucks. The hope here is that such an act will provide a forceful nudge to state residents to drive more electric vehicles that typically have no tailpipe emissions. If, in addition, this act also encourages research on batteries then so much the better.
The problem with this “inside the box” thinking is that even though it makes sense at the national level, and certainly at the level of the entire planet, we have been doing too little and at too slow a pace. In the meantime, we increasingly hear and see stories of record high temperatures in the American west, devastating floods in Sydney, Australia, unbearable heatwaves in New Delhi, India, and dramatically high rainfall leading to widespread flooding in Pakistan.
So, it’s time to think outside the box. This means thinking seriously about geoengineering or climate engineering. This kind of engineering embraces two types of technologies: carbon dioxide removal and, most interestingly, sunlight reflection methods.
Carbon dioxide removal technologies denote processes, such as direct air capture, that seek to address a key cause of climate change by lowering atmospheric carbon dioxide concentrations. However, as Cornell researcher Doug MacMartin has noted in recently published research, current strategies for carbon dioxide removal are either not at scale or are too expensive to meaningfully reduce the 40 billion tons of carbon dioxide emitted by humans each year.
This brings us to solar radiation modification which is a potentially valuable climate change mitigation strategy. The technology here involves injecting sulfate aerosols into the stratosphere so that more sunlight bounces off the Earth’s atmosphere instead of being absorbed by the “blanket covered” earth. The key point is that sunlight reflection methods, including stratospheric aerosol injection, can offset the effects of climate change by cooling planet earth.
Research on climate engineering is very new and we are nowhere close to knowing all the impacts, both positive and negative, of employing the technologies suggested by this line of research. Although policies based on thinking “inside the box” can continue to be used, we are now at a stage in our fight against climate change where we need to seriously consider augmenting our traditional policy toolkit with approaches that hold promise but about which there is also some uncertainty. Expanding our set of policy instruments cannot make us worse off because we always have the option of not using a policy if it turns out that the use of this policy will not make our planet more livable for the present and future generations.
Batabyal is the Arthur J. Gosnell professor of economics and the Interim Head of the Department of Sustainability, both at RIT, but these views are his own."