To limit future climate change, global climate models increasingly rely on unproven carbon negative emission technologies (NETs). Certain NETs such as afforestation/reforestation or coastal blue carbon are entirely based on promoting and supporting natural (green) means to remove CO2 from the atmosphere. Others such as direct air capture, are highly engineered (gray) processes. Others are some hybrid of green and gray processes, such as bioenergy with carbon capture and storage, biochar, or accelerated weathering. These NETs have very different biophysical potential and limitations that are only now being discussed in the literature, and the expected costs from the pathways vary dramatically.

Using the Global Carbon Assessment Model, an integrated assessment model developed at the University of Maryland, this CoLab extends the computational capacity of the model, and expands its scope to consider regional economic factors and earth systems processes important for understanding the ecosystem services that green NETs could provide. Using this enhanced form of GCAM we are exploring the tradeoffs inherent in NETs and assessing the potential to deploy NETs within the Chesapeake Bay region. Special attention is being paid to decision-making, accounting, and governance issues of deploying NETs at scale. By working collaboratively across disciplinary boundaries, we are able to refine and elaborate on our model, enabling us to quantify the absolute contribution NETs could have on global climate cycling in light of the biophysical, economic, and logistical constraints so that we can help set realistic expectations and goals.