Learning from rivers about long-term controls on Earth’s climate
The study of rivers offers important insights into why our planet looks the way it does. The interaction of rocks with water shapes landscapes, supplies nutrients to ecosystems, and consumes atmospheric CO2. The relative stability of Earth’s climate over the past 500 million years has allowed life to flourish, and is controlled by a delicate and complex balance between tectonics, rock weathering, and the evolution of life. It is, however, punctuated by large climatic perturbations that have typically resulted in mass extinctions.
River catchments integrating over large continental areas allow us to assess the net effects of water-rock interaction on a globally significant scale. By studying world's large rivers we can therefore better understand and quantify the global importance of rock weathering and its impact on Earth's climate. However, representative sampling of large rivers is non-trivial and requires advanced techniques. I will demonstrate some state of the art techniques employed by the Cambridge rivers research group, as well as how our research in Southeast Asia is helping shed light on the complex controls on the global climate.