Reservoir CO2 and CH4 emissions and their climate impact over the period 1900-2060
Abstract
Reservoirs are essential for human populations, but their global carbon footprint is substantial (0.73-2.41 PgCO2-equivalent yr−1). Yet the temporal evolution of reservoir carbon emissions and their contribution to anthropogenic radiative forcing remains unresolved. Here we quantify the long-term historical and future evolution (1900-2060) of cumulative global reservoir area, carbon dioxide and methane emissions and the resulting radiative forcing. We show that global reservoir carbon emissions peaked in 1987 (4.4 TmolC yr−1) and have been declining since, due largely to decreasing carbon dioxide emissions as reservoirs age. However, reservoir-induced radiative forcing continues to rise due to ongoing increases in reservoir methane emissions, which accounted for 5.2% of global anthropogenic methane emissions in 2020. We estimate that, in the future, methane ebullition and degassing flux will make up >75% of the reservoir-induced radiative forcing, making these flux pathways key targets for improved understanding and mitigation.
- Publication:
-
Nature Geoscience
- Pub Date:
- September 2022
- DOI:
- 10.1038/s41561-022-01004-2
- Bibcode:
- 2022NatGe..15..700S