Anthropogenic perturbation of organic carbon burial in global lake sediments

Lake sediments constitute a large and efficient carbon sink and thus have a cooling effect on climate.

Current estimates of the global-scale magnitude of the lake carbon sink are however very uncertain as they build on extrapolation from few, geographically biased measurements.

In addition, it is presently unknown how the continued anthropogenic perturbations to climate and land-use will affect global lake carbon burial in the future.

This research will take a new approach, by building a process-based model of particulate organic carbon (POC) burial in lake sediment that will be validated at different scales, and then driven by the big data supplied by the climate science community through the ISIMIP project: globally-gridded data on climate, land use, water flow, and the thermal structure of >17,000 lakes, at a daily time step, stretching from the past (1861) to the future (2099), including ensemble runs of 4 climate models and 3 future emission scenarios.

This will provide a robust estimate of global POC burial, render the first estimate of the efficiency of global POC burial, and give the first quantification of the anthropogenic perturbation of global POC burial from the past into the future.

This approach to global quantification of an inland water carbon flux is consistent with other parts of the Earth system, thus taking a critical step towards the inclusion of inland waters into Earth System Models, and thus improved climate change projections.