Andreas Schmittner is a scientist interested in Earth’s climate system. Most of his work is focused on the oceans, their physics, biology, chemistry and variability on decadal to millennial time scales. He works to understand the causes for today’s global deep overturning circulation, how and why it has changed in the past, how it may change in the future due to natural or human influences, and how it impacts climate, ecosystems and biogeochemical cycles including isotopes. He develops, improves, analyzes, and uses numerical (computer) models.