Earth's sediment cycle during the Anthropocene

The global sediment cycle is a fundamental feature of the Earth system, balancing competing factors such as orogeny, physical-chemical erosion and human action. In this Review, values of the magnitudes of several sources and sinks within the cycle are suggested, although the record remains fragmented with uncertainties. Between 1950 and 2010, humans have transformed the mobilization, transport and sequestration of sediment, to the point where human action now dominates these fluxes at the global scale. Human activities have increased fluvial sediment delivery by 215% while simultaneously decreasing the amount of fluvial sediment that reaches the ocean by 49%, and societal consumption of sediment over the same period has increased by more than 2,500%. Global warming is also substantially affecting the global sediment cycle through temperature impacts (sediment production and transport, sea ice cover, glacial ice ablation and loss of permafrost), precipitation changes, desertification and wind intensities, forest fire extent and intensity, and acceleration of sea-level rise. With progressive improvements in global digital datasets and modelling, we should be able to obtain a comprehensive picture of the impacts of human activities and climate warming. Sediment budgets have changed substantially in the Anthropocene epoch, the period between 1950 and the present. This Review provides an overview of sediment sources, fluxes and loads, outlines the impacts of human activities, and highlights the predicted effects of climate warming on these factors.

Automated summary

The global sediment cycle is a critical aspect of the Earth system, but human activities and climate warming have significantly altered the sources and sinks of sediment.