The Promise and Pitfalls of Negative Carbon Emissions – A Regional Case Study of the Chesapeake Bay Watershed

Economics; Environmental Engineering; Environmental Sciences; Agricultural and Resource Economics; Physical and Environmental Geography

To limit future climate change, global climate models increasingly rely on unproven negative carbon emission technologies - we will develop models to assess their potential at regional scales.

Research Interests
  • Climate change
  • integrated modelling
  • negative emissions

The 2015 United Nations Paris Agreement on Climate Changelaid out a narrow path for limiting the world’s warming to 2ºC. That pathincludes the deployment of carbon negative technologies that effectively runclimate change in reverse. These technologies have obvious appeal and buy timeto transition our energy systems away from fossil fuels. But it is notimmediately obvious that any of the proposed technologies could ever bedeployed at the necessary scales given the alignment of economic,environmental, and engineering factors that would be needed. In this project,an interdisciplinary team with expertise in these three domains will develop aregional model to assess the potential impact, tradeoffs, and costs of negativecarbon emissions on the Chesapeake Bay region.

The Integrated Assessment Models (IAMs) used by the UN areglobal in scale and are very limited in how much they can inform regional andlocal forecasting and planning. That matters because many negative carbonemissions technologies could have significant impacts on land use and food,energy, and water systems. The most common proposed form of negative emissionstechnology, called bioenergy with carbon capture and storage (BECCS), would requirethe planting of significant areas with bioenergy crops. IAMs suggest that asignificant fraction of the world’s arable land would need to be planted withBECCS in order to meet warming targets. The models cannot yet, at scales neededfor national and sup-national policy development, tell us how the accommodationof these projects would impact competing land uses such as agriculture for feedinga growing world population. IAMs do not generally forecast the ways in whichthe deployment of BECCS or other negative emissions technologies might beimpacted by or impact the deployment of utility-scale renewable energy projectsthat are land-use intensive. Understanding how regional decision making islikely to play out is important because if the conditions that would enablethese technologies to flourish is unlikely to exist, alternatives will need tobe developed as soon as possible.     

We propose to carry out the first regional assessmentof carbon negative technologies using the Chesapeake Bay watershed as a casestudy because it contains much of the agricultural land in the mid-Atlantic USas well as major urban areas (including the nation’s capital), coastalinfrastructure, agricultural activity, and carbon storage sites. We will buildtwo kinds of models to perform the assessment. The first is a regional,economic equilibrium model that will enable the study of the agriculturalsystems within the watershed that might support the deployment of BECCS andother negative emissions scenarios under different conditions. The second is anearth systems model of the region that will enable us to quantify the carboncycling impacts of these technologies at a regional scale. Together, this pairof models will enable us to quantify the absolute contribution thesetechnologies could have on global climate cycling in light of the biophysical,economic, and logistical constraints so that we can help set realisticexpectations and goals.

Desired outcomes

At the end of this project, we aim to have achieved thefollowing:

- Built a coupled regional economic equilibriummodel and earth systems model for the Chesapeake bay watershed that allows usto understand the impacts of different negative emissions pathways on carboncycling and land/water/energy use.

- Published a journal paper reporting on ourfindings providing insight about the viability of various land-use intensivenegative emissions pathways.

- Submitted a proposal to the NSF program oncoupled natural human systems program.