Future Tense

What Slate Readers Think About Geoengineering

Readers respond.

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As part of our new Futurography project, Future Tense spent much of January introducing readers to the ideas and debates surrounding geoengineering—the practice of tinkering with the Earth’s atmosphere to fight climate change. As the month came to a close, we asked for your thoughts on the topic, inquiring about where you stood on the issues and how you felt that scientists and policymakers should proceed. While the results of our survey were far from scientific, we were struck by the variety of your responses—and the intensity of your engagement. We hope that you’ll follow along with similar enthusiasm as we look into the power and promise of algorithms this month. For now, however, here are some of your opinions on geoengineering.

Respondents were split on the question of whether we should be moving ahead with geoengineering technologies at all. Some felt that the complexity of the topic itself made it difficult to decide definitively, with one observing, “I think your own coverage of this issue demonstrates that it is a topic that defies categorical evaluation.” Others recognized that it might be necessary, whether or not it was actually desirable. One person wrote: “Nobody thinks we should but some fear we will have to.” Even those who felt it might be worth attempting geoengineering, however, tended to stress that we should proceed with caution.

Most readers who accepted that it might be worth attempting geoengineering projects tended to emphasize carbon dioxide reduction through filtration systems that pull greenhouse gasses out of the air over solar radiation management, which involves reflecting sunlight back into space to cool the Earth. In this, they followed the positions of researchers such as Raymond Pierrehumbert, a vocal critic of the latter method who earned accolades from many survey respondents. Others seemed to think that even these endeavors should be secondary to simply finding alternative energy sources. If we’re going to invest money into climate technologies, one typical respondent observed, “let’s put it into building the infrastructure for viable alternatives to carbon emission[s].” The so-called natural approach to carbon dioxide reduction—forestry and crop management—captured readers’ attention as well, with at least one noting that it might be our safest bet: “We have a pretty good idea what the effect of planting a forest is 10,000 years from now. Can’t really say the same for solar radiation management,” the respondent wrote.

Despite that, a significant proportion of geoengineering believers acknowledged that albedo modification—that is, increasing the Earth’s reflectivity to prevent sunlight from warming the planet in the first place—might be worth attempting. “If fossil fuel emissions are not reduced in a timely manner over the next 10 years, I think a small amount of [solar radiation management] in conjunction with emissions reductions could work well to stabilize the climate,” one wrote. Others argued that whatever the risks, it might be morally necessary to embrace solar radiation management. “If we start to experience runaway global warming the only thing that will save millions of people in low lying areas like Bangladesh is SRM,” one wrote, before going on to insist that it would be “genocidal” to neglect such solutions.

Despite that, many pointed to important objections, including the concern that albedo modification presents a moral hazard: the danger that small fixes might dissuade us from pursuing larger solutions. Others worried that it requires too long a commitment for too little effect, as did one who echoed Pierrehumbert’s cautions: “The argument against geoengineering by albedo hacking … I find most convincing is that you have to commit to keep doing it basically forever, and if you are ever forced to stop, the world will face catastrophic rapid warming.” Some suggested that their concerns weren’t so much scientific as political, since geoengineering would “require strong and adaptive social institutions, institutions which currently are not up to the task.”

The most common argument that had swayed readers against geoengineering? That we just don’t know enough about it at this point. “We don’t know [its] full consequences and it doesn’t treat the root problem,” one wrote. Another observed that the “potential for unintended environmental consequences (DDT and birds comes to mind) gives me pause.” The relative novelty of most geoengineering proposals weighed heavily on many. As one respondent noted, “It took decades for scientists to characterize relatively well the problem of anthropogenic global warming and marshal the political and popular will for any emission reduction.”

Some readers, especially those who aren’t scientists themselves, were reluctant to try to set research priorities, but a few had ideas. Arguing that “computer simulations and lab experiments are not enough,” one respondent proposed that we should attempt small-scale implementation. Taking a contrary position, others wrote that there’s no way to really know whether and how geoengineering will work unless we implement it on a global scale. The problem is that to do so might be to court catastrophe: “You are never gonna know for sure that going full planet with something isn’t going to have unanticipated negatives.”

Perhaps the biggest questions readers had was: How can geoengineering be “in any way … preferable to reduction of fossil fuel use”? Above all else, the results suggest that this is and will remain a contentious topic, but we hope you’ve taken as much from our exploration of as we have.

This article is part of the geoengineering installment of Futurography, a series in which Future Tense introduces readers to the technologies that will define tomorrow. Each month from January through June 2016, we’ll choose a new technology and break it down. Read more from Futurography on geoengineering: