Global carbon sequestration through continental chemical weathering in a climatic change context

Abstract

This study simulates carbon dioxide (CO₂) sequestration in 300 major world river basins (about 70% of global surface area) through carbonates dissolution and silicate hydrolysis. For each river basin, the daily timescale impacts under the RCP 2.6 and RCP 8.5 climate scenarios were assessed relative to a historical baseline (1969-1999) using a cascade of models accounting for the hydrological evolution under climate change scenarios. Here we show that the global temporal evolution of the CO₂ uptake presents a general increase in the annual amount of CO₂ consumed from 0.247 ± 0.045 Pg C year^-1 to 0.261 and 0.273 ± 0.054 Pg C year^-1, respectively for RCP 2.6 and RCP 8.5. Despite showing a general increase in the global daily carbon sequestration, both climate scenarios show a decrease between June and August. Such projected changes have been mapped and evaluated against changes in hydrology, identifying hot spots and moments for the annual and seasonal periods.