According to researchers, it is probably not going to be enough for the Earth to escape catastrophic damage from climate change by just reducing the emissions of greenhouse gas.
Further steps will be needed, and one choice is solar geoengineering, which could reduce temperatures by techniques such as reflecting sunlight away from the Earth by deploying aerosols in the stratosphere. However, the outlook of experimenting with the Earth’s atmosphere has left some people doubtful, and some completely frightened, of the process.
A new study titled “Mission-Driven Research for Stratospheric Aerosol Geoengineering” published in Proceedings of the National Academy of Sciences on January 7th, 2019, endeavors to establish a roadmap for responsible exploration of geoengineering.
Part of the genesis of this paper is that a long time ago I got tired of going to meetings and not being able to say much more than, ‘If you do geoengineering, it will get colder’. We actually need to do the research to understand what the impacts are and understand the uncertainties. There are obvious questions about how to govern the technology if it was actually being deploying, or how to make decisions about deploying it. But there’s also been a lot of discussion about how to even govern the research process—and that question should start with understanding what sort of research needs to be done.
Douglas MacMartin, Senior Research Associate and Senior Lecturer, Mechanical and Aerospace Engineering, Cornell University.
MacMartin is the lead author of the study.
Although scientific research has customarily been motivated by the instinctive curiosity of researchers struggling with an interesting question, this research identifies that geoengineering needs a more mission-driven approach with a clear objective: informing policy.
“It’s the research community’s responsibility to ensure that before people get to a point of saying, ‘Let’s consider using geoengineering,’ we’re able to provide enough information to either say ‘No, here’s why not’ or ‘If you were to do it, this is the best way to do it, here is what we think the impacts are, here are the uncertainties’.” MacMartin said.
The focus of the study, which was co-authored by MacMartin and Ben Kravitz, assistant professor at Indiana University, is on the concept of emitting sulfate aerosols into the stratosphere, simulating the volcanic eruption. This obeys a natural process and hence would limit the “unknown unknowns” and allow scientists to calibrate their models. This is significant because the research finds that near-term geoengineering research will chiefly be modeling.
I think it’s reasonable to expect that there will be some need for [more] tests, but those will always be small. The upshot of that is, in terms of research governance, it does not necessarily need to address transboundary issues or worry about a slippery slope to deployment in which you agree to one scale of experiment, and then it gets a little bigger, and a little bigger still. The research is always going to be very small scale, so there’s a bright line between activities that look like research and activities that look like deployment. Engaging in geoengineering research itself doesn’t have to be scary. I think if you look carefully at what needs to be done, it looks a lot more like climate science research, but focused on a particular goal.
Douglas MacMartin, Senior Research Associate and Senior Lecturer, Mechanical and Aerospace Engineering, Cornell University
According to a recent report from the United Nations’ Intergovernmental Panel on Climate Change, global warming will cross 1.5 ○C around 2040, and based on this report, MacMartin sees an emergent requirement to start making inroads in investigating geoengineering research. It could take around two decades before researchers can help policymakers to make an informed decision in relation to the effectiveness of the technology.
I think the main message of this study is that it explicitly asks us to prioritize our research. What do we want to learn, how do we want to learn it, and why will that resolve the most important uncertainties in geoengineering? Large engineering projects handle these sorts of questions all the time with well-established tools. It seems like modifying the climate, the largest engineering project humanity has ever faced, could use some of the same tools.
Ben Kravitz, Assistant Professor, Indiana University.
According to MacMartin, geoengineering must be regarded as a supplement to lowering greenhouse gas emissions and not as an alternative. He prefers to consider the process as an airbag.
“If you know you’re going to get into an accident, you ought to take your foot off the gas and put it on the brake, but you might want airbags, too,” MacMartin said. “The airbag doesn’t change the fact you’re going to get into an accident, but it does mean you’ll have less damage.”
The study was supported by the Atkinson Center for a Sustainable Future.