Grant: Alliance Grants

In 2019, the Intergovernmental Panel on Climate Change (IPCC) adopted a new Methodology Report that require countries to include greenhouse gas (GHG) emissions from flooded lands in their National Inventories Report. Proposed estimation approaches rely on simple averages of emissions rates per climate zone, inappropriate for large countries with diverse landscapes such as Canada. This proposal aims at acquiring the data necessary to assess and calibrate existing models to the Canadian context but also to develop new models to simulate the internal dynamics of methane (CH4) and carbon dioxide (CO2) and estimate their release to the atmosphere through the multiple emissions pathways. In particular, we will engage with multiple partners (hydropower companies, ECCC, conservation authorities) to establish and jointly conduct a robust sampling program in a diverse set of reservoirs. The resulting data will yield five main deliverables. (1) It will provide the first standardized set of empirical data from diverse Canadian reservoir systems that will in turn be used to validate and calibrate existing statistical models as well as a process-based physical-biogeochemical approach to model CH4 and CO2 dynamics across various environmental settings. (2) We will better constrain the two most variable and difficult to measure components of aquatic GHG flux pathways, namely CH4 bubbling and GHG degassing downstream of dams, and integrate those with the process-based approach. (3) We will evaluate the applicability of our new approach to the lesser studied reservoir types that also dominate North America, flood control and low flow augmentation. (4) We will evaluate how reservoir operations (water level control) can be adapted to reduce the GHG footprint of reservoirs. (5) Lastly, we will provide our governmental partner (ECCC) with estimates of the ensemble of the nation's reservoir footprint using both the Canadian calibrated G-res and process-based models. Overall, the approach will provide Canada with an updated and dynamic methodology to estimate the current (and future) GHG footprint of the nation's flooded land as well as provide general knowledge and tools that could be mobilized abroad.