The Roles of Rock Formation and Weathering in Long-Term Climate Change

Chapter 7 explores the question: how does rock formation and weathering help drive long-term climate change? This exploration is focused on the chemical processes of rock formation and weathering that release CO[[inf]]2[[/inf]] to the atmosphere or consume CO[[inf]]2[[/inf]] from the atmosphere. Weathering of silicate rocks uses atmospheric CO[[inf]]2[[/inf]], whereas weathering of organic-carbon-rich rock (e.g. coal) releases CO[[inf]]2[[/inf]]. Feedbacks between atmospheric CO[[inf]]2[[/inf]] content, global climate state, and the rates of chemical weathering have created a self-balancing system that has stabilized Earth’s climate within a habitable range for ~the last 4 billion years. Tectonic uplift of unweathered rocks in a mountain range can disrupt this balance for timespans of a few million to a few tens of millions of years, driving the Earth from a Greenhouse state into an Icehouse state until the balance is restored.