Plio-Pleistocene increase of erosion rates in mountain belts in response to climate change

Here, we review an ensemble of observations that point towards a global increase of erosion rates in regions of elevated mountain belts, or otherwise high relief, since the onset of Northern Hemisphere Glaciation about 2–3 Ma. During that period of Earth’s history, atmospheric CO2 concentrations may have dropped, and global climate cooled and evolved towards high-amplitude oscillating conditions that are associated with the waxing and waning of continental ice sheets in the Northern Hemisphere. We argue for a correlation between climate change and increased erosion rates and relief production, which we attribute to some combination of the observed cooling, onset of glaciation, and climatic oscillation at orbital timescales. In our view, glacial erosion played a major role and is driven by the global cooling. Furthermore, analyses of the sedimentary fluxes of many mountain belts show peaks of erosion during the transitions between glacial and inter-glacial periods, suggesting that the variable climatic conditions have also played a role. Terra Nova, 28: 2–10, 2016 FORUM: The Editors of Terra Nova invite readers to contribute to a discussion of this topic on our forum at https://terranovadebates.wordpress.com/