资源环境科技发展态势分析平台

Uplift and erosion of the Himalaya and Tibetan Plateau has resulted in deposition of some of the largest sedimentary masses on Earth. Chemical weathering of these materials has been invoked as a primary driver of long‐term global cooling because weathering of silicate material consumes atmospheric CO₂. We here combine geochemical data from scientific drill sites in the Arabian and South China Seas, together with sediment mass flux budgets, to estimate changes in chemical weathering fluxes for the Indus, Mekong and Pearl river systems. The rate of CO₂ consumption decreased by 50% between ∼16 and 5.3 Ma, especially in the Indus system, as onshore erosion slowed and provenance shifted away from mafic arc units in the suture zone. Falling chemical weathering fluxes during a period of global cooling refutes the idea that Himalaya–Tibetan Plateau uplift drove Neogene global cooling.