Even the most optimistic pathways to meeting the goals of the Paris climate accord require actively removing existing carbon dioxide from the atmosphere. But the methods for doing so are largely unknown to the public. A new study now suggests public support for carbon dioxide removal (CDR) strategies depends at least in part on how much a strategy is seen as interfering with nature and whether the public is aware of its risks and benefits.
“Carbon dioxide removal strategies raise ethical issues and questions of technical feasibility,” says Kim Wolske, a research associate and assistant professor at the University of Chicago Harris School of Public Policy. “Understanding which CDR strategies are seen as most acceptable to the public—and why—may provide valuable inputs for policy decisions around CDR deployment.”
Wolske, along with co-authors Kaitlin Raimi, Victoria Campbell-Arvai and Sol Hart, all from the University of Michigan, examined public support for three different types of CDR strategies: bioenergy with carbon capture and storage (BECCS), direct air capture (DAC), and afforestation and reforestation (AR). Overall, support was higher for afforestation and reforestation than for the other two methods because it was perceived to tamper less with nature.
Participants were given one of three mock Associated Press articles that explained the basic concept of CDR followed by a description of one of the specific strategies above and a corresponding illustration. Whereas afforestation and reforestation involves planting trees to soak up CO2 from the atmosphere —a biological process already found in nature— bioenergy with carbon capture and storage requires large areas of land and complex technology to ultimately capture and bury carbon dioxide underground. Direct air capture, in which a group of large fans pull CO2 out of the air and separates the carbon, suffers from similar drawbacks. Those factors may have contributed to respondents perceiving afforestation and reforestation as being more ‘natural’ than the other strategies, and therefore more favorable.
For half of participants, the mock Associated Press article also described the tradeoffs associated with the CDR strategy they read about, along with a figure listing its pros and cons. Support decreased among all three strategies when participants were presented with the information.
Overall, the study’s findings point to a potential mismatch between which CDR strategies the public finds most acceptable and which are the most effective and viable. Support was greatest for afforestation and reforestation, which is also the least effective of the three strategies for reducing carbon emissions—estimated to reduce global CO2 emissions by about 15 percent. The other strategies are estimated to abate between 30 and 50 percent of emissions. Further, bioenergy with carbon capture and storage is considered to be the closest to large-scale deployment.
While most research on geoengineering has focused on perceptions of solar radiation management, the study is the first to compare support for the three most commonly cited strategies in climate modeling scenarios.
“Knowledge of CDR strategies among the public is relatively low,” says Wolske, “which means that how policymakers and the media present these strategies could have major consequences for their future acceptance and deployment.”