Authors: Jay Fuhrman1, Haewon McJeon2, Scott C. Doney3, William Shobe4 and Andres F. Clarens1*
1Department of Engineering Systems and Environment, University of Virginia, Charlottesville, VA, United States
2Joint Global Change Research Institute, University of Maryland and Pacific Northwest National Laboratory, College Park, MD, United States
3Department of Environmental Sciences, University of Virginia, Charlottesville, VA, United States
4Batten School of Leadership and Public Policy, University of Virginia, Charlottesville, VA, United States
Full citation: Fuhrman, Jay, Haewon McJeon, Scott C. Doney, William Shobe, and Andres F. Clarens. “From Zero to Hero?: Why Integrated Assessment Modeling of Negative Emissions Technologies Is Hard and How We Can Do Better.” Frontiers in Climate 1 (2019): 11. https://doi.org/10.3389/fclim.2019.00011.
Abstract: Integrated Assessment Models (IAMs) of the Earth’s economic and climate system increasingly rely the presumed future ability to achieve negative emissions in order to limit global warming to “well below 2 C” by 2100. The scales at which these models project so-called “negative emissions technologies” (NETs) to be deployed rivals that of our current (positive) emissions. There are a number of ways in which we could in theory remove CO2 from the atmosphere, all of which have their own set of potential synergies and tradeoffs with other goals for sustainable development. Yet the vast majority of scenarios assume the availability of just two NETs: bioenergy with carbon capture and storage, and afforestation. Just as the impacts of climate change itself will fall disproportionately on the developing world, IAM results suggest that so too, would the impacts of removing already-emitted CO2 from the atmosphere using these methods. In all regions of the world but especially Asia, Latin America, and Africa, enormous amounts of land would need to be converted to bioenergy crop cultivation or managed forest, with profound implications for food security and biodiversity. Only a few recent studies have incorporated direct air capture, a fully engineered process previously thought too expensive to be viable but now receiving increasing attention. Other NETs (e.g., coastal wetlands restoration, accelerated weathering) have largely been excluded from IAM scenarios because they lack obvious connections with existing economic sectors. Our analysis finds that more complete treatment of NETs by IAMs could highlight substantial opportunities for more limited, sustainable deployment now, provided the appropriate policy incentives. But modeling results suggesting large-scale future deployment of NETs should be communicated to and interpreted by policymakers and other stakeholders as warnings of the potential impacts of the NETs themselves, rather than prescriptive licenses to delay taking action and attempt to reverse the damage later.
Read the full article in Frontiers in Climate here.