A third contribution to the climate/erosion debate

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.

Lack of a Weathering Signal with Increased Cenozoic Erosion – Kevin P. Norton & Fritz Schlunegger

Debate Articles: Have changes in Quaternary climate affected erosion?

Terra Nova is initiating a new type of article this month: “debate articles”. We have invited two prominent groups of researchers to present evidence and defend their opinion concerning either side of an ongoing debate. In this first instance, the debate concerns the effect of the cooling climate of the Quaternary on the efficiency of erosion processes at the Earth’s surface, and whether or not cooling of the Earth’s atmosphere has led to a marked increase in erosion rate and sedimentary flux of continental material into the world’s oceans. This debate is quite ancient and can be traced back to papers by Molnar and England (1990) and Zhang et al. (2001). It has been recently reinvigorated by the compilation of a worldwide database of low-T thermochronometric ages (Herman et al, 2013) providing constraints on the rate of continental erosion, on the one hand, and a fresh look at the sedimentary record (Willenbring and von Blanckenburg, 2010) and how it is inherently affected by hiatus and reworking, on the other hand. Terra Nova’s contribution is to publish back to back what could be viewed as two review papers summarising evidence supporting either side of the argument and to offer to the research community the opportunity to participate in and contribute to this debate. To this effect, we have also opened this forum, moderated by our scientific editors, to which we invite all our readers to contribute by commenting on the evidence presented by the authors of the debate articles, and their proposed interpretation, but also by directing our readers to other or new evidence that can contribute to the debate as well as providing suggestions on how we could, as a community, help resolve this very important question.

Jean Braun
Scientific Editor, Terra Nova

Please read the two articles, which are freely available on Terra Nova‘s website:

Plio-Pleistocene Increase in Erosion Rates in Mountain Belts in response to Climate Change (Frédéric Herman and Jean-Daniel Champagnac)

The null hypothesis: globally steady rates of erosion, weathering fluxes and shelf sediment accumulation during Late Cenozoic mountain uplift and glaciation (Jane K. Willenbring and Douglas J. Jerolmack)