Considerations related to ecosystem carbon accounting & first order approximations for the Oil Sands Region of Alberta

This report was produced by Pathways Alliance to evaluate whether land management should be included when accounting for the impact of the oil sands sector on greenhouse gas emissions. The main objectives are: (1) to describe the regulatory context and accounting rules applicable to an impact assessment of oil sands on ecosystem carbon, and (2) to provide an approximation of the magnitude of ecosystem carbon affected by oil sands development and reclamation. This was accomplished through an in-depth review of regulatory documents related to carbon and greenhouse gas accounting, which informed order-of-magnitude estimations and the quantification of impacts.

The oil sands region, once rich in ecosystem carbon, has experienced a significant loss of 188.25 to 237 Mt due to development that reduced natural land cover by 12%, with surface mining as the dominant contributor. Although some carbon recovery is possible through reclamation, estimated gains of 3.49 to 4.01 Mt over 20 years are minimal compared to the losses, and full restoration of biomass and organic soil carbon would take centuries or longer. These findings align with other studies, despite differences in scope, and highlight the need for ambitious reclamation strategies and more advanced modeling to address the complex dynamics of ecosystem carbon.