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Sediment accumulation in lakes provides a small but permanent carbon sink. To date, global estimates of the C cycle have barely considered variations in lake carbon burial. To improve the understanding of carbon storage in lakes this study analyzed the sedimentary record of 228 European lakes concerning long‐term carbon burial and its correlation to lake and catchment properties. The results suggest that carbon mass accumulations in small lakes are significantly lower than those used for global estimates so far. On the other hand, the total surface area of small lakes has been severely underestimated. Results from calculations based on a Pareto distribution show that total lake surface is 240,000 km2 in Europe. We estimate total C burial in European lakes at 1.25 Mt yr−1. Half this storage takes place in boreal lakes of northern Europe, although they contribute up to 65% to the European lake surface. This is due to generally lower carbon burial rates in this region. Carbon mass accumulation rates increased in many lakes between 5000 to 2000 years BP. This coincides with increased clastic inputs due to land use change, i.e., increasing cropland coverage and soil erosion. On average, carbon accumulation rates are twice as high in younger sediments at 20 cm depth when compared to the long‐term mean.

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Data are presented about modern sediment discharge of the Swiss rivers and related to the size of catchments. The information reveals that the Central Alps have experienced denudation rates of ≈0.15 mm yr−1 in the foreland, and ≈0.5 mm yr−1 in the Alpine core. Mapping, however, indicates that modern erosion only affects 30–50% of the Alpine surface, and that fluvial and associated hillslope processes have focused erosion in 50–200‐m‐deep valleys. These valleys are incised into the glacial surface. If this limited spatial extent of erosion is considered, then effective erosion rates are significantly higher than average denudation rates. These effective rates equal or locally exceed modern rates of rock uplift. This implies that the modification of erosional processes related to the Pleistocene/Holocene climate change has resulted in an increase in the relief at a local scale. At a drainage basin scale, however, the relief appears not to change at present.

Water reservoirs, lakes, and larger basins, including their drainage areas, represent sedimentologically closed to semi-closed denudation-accumulation systems. The mean rates of mechanical denudation, DR , and clastic sedimentation, SR , are related by the ratio of the drainage/lake area, A /A . If the latter is known, DR (or the specific sediment yield SY in t per km/a) can be calculated from SR , or vice versa. The best data for modern SY mainly come from the sediment fills of artificial reservoirs. Small drainage areas of mountainous regions show SY values up to two orders of magnitude higher than lowlands and approximately one order higher than larger regions of mixed relief. This is also true of arid to semi-arid zones which often provide approximately as much sediment (SY) as humid temperate and even tropical zones of comparable relief. Lithology and climate (river runoff) also may play some role for SY from catchments of limited size. The importance of these factors is exemplified by perialpine lakes and two East African lakes. Sediment yields gained from some large reservoirs compare well with long-term denudation rates derived from geological studies (e.g., the Tarbela dam reservoir along the Indus River). In many other cases, human activities have raised SY by factors of 2-10, locally up to '100. Artificial reservoirs in mountainous regions with SY in the range of 300-2000 t per km/a tend to become filled within several tens to hundreds of years; some have even shorter lifetimes. Perialpine lakes of the Alps and British Columbia are strongly affected by delta prograding and have lifetimes mostly between 15 and 40 ka. Closed lake systems in deep morphological depressions (Lake Bonneville, Aral Sea, northern Caspian Sea) have a high potential for sediment storage up to the level of spillover and therefore can persist over long time periods. Basins with markedly subsiding basin floors (lakes of the East African rift zone, the southern Caspian Sea, and the Black Sea, both on oceanic crust) can survive for many Ma in the future, despite relatively high terrigenous input.