Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change location:Incline Village, Nevada, USA date:8-10 September 2008
The number of artificial reservoirs has increased dramatically in last hundred years, a time when anthropogenic soil erosion rates have also increased in many areas. Previous estimates of total organic carbon burial in reservoirs are generally in the range of 0.2 to 0.4 Pg yr-1. However, a variety of data sources suggest that total global clastic sedimentation in reservoirs may be 35 Pg yr-1 or more. If this sediment averages 2% organic carbon then total carbon burial in reservoirs is ~0.7 Pg yr-1. In areas where soil surface erosion is a minor part of sediment yield the fractional organic carbon content may be lower. Considerable uncertainty regarding the magnitude of carbon burial in reservoirs results from: 1) rapid increases in numbers of reservoirs; 2) under-representation of small reservoirs in available datasets; 3) insufficient data on reservoir sedimentation rates and the organic carbon content of reservoir sediments; and 4) temporal change in sedimentation rates. Available evidence suggests that total reservoir carbon burial rates are likely under- rather than overestimated.