Global chemical weathering patterns set by glacial erosion

Chemical weathering plays a crucial role in the long-term evolution of Earth’s climate, yet the spatial heterogeneity of the weathering rate and intensity driven by glacial erosion owing to glacial shrinkage worldwide is poorly constrained. Here we develop a global data set of cation denudation rate (CDR) and intensity (CDI) from mountain ranges, glacial regions and glacial catchments worldwide. Contemporary weathering rate and intensity are ~ 2 times higher than two decades ago, 2 ~ 6 times higher than Greenland ice sheet basins and over 2 times higher than whole ice sheet means. Their spatial patterns are characterized by relatively high weathering rate and intensity in low latitudes in contrast to low weathering rate and intensity in high latitudes. This is closely related to glacial erosion involving with temperature, precipitation, discharge, altitude and slope, suggesting that the element mobilization and CO2 budgets caused by glacial chemical weathering are likely to enhance in a warming landscape. We contend that subglacial chemical weathering is far more important than previously thought and should be considered in elemental cycles and carbon cycling.