Earth System Biogeochemistry explores how the major element cycles of life have changed over the course of Earth history. We use computational methods to simulate carbon and nutrient cycling and to match these simulations to available reconstructions. One main focus of this work addresses the role of the global carbon cycle in climate change of the geologic past. The second focus is on tracing the processes that sustain the ocean’s biological productivity by supplying essential nutrients. Better understanding the natural processes that have shaped global nutrient and carbon cycling informs how the environment may change in the future.