Terra Nova is publishing a third contribution to the ongoing debate on whether changes in Quaternary climate have affected erosion. Following the articles by Herman & Champagnac (Plio-Pleistocene Increase in Erosion Rates in Mountain Belts in response to Climate Change) and by Willenbring & Jerolmack (The null hypothesis: globally steady rates of erosion, weathering fluxes and shelf sediment accumulation during Late Cenozoic mountain uplift and glaciation), we were contacted by Kevin Norton and Fritz Schlunegger, who wanted to put forward a third possibility. In their article, they present a new chemical weathering model and previously published geochemical evidence to suggest that a chemical weathering signal need not necessarily follow from an increase in physical rates. The article is now online and free to view. We would welcome your comments on how you feel this article adds to the existing debate.