Earth and Planetary Science
EPS Geophysics

Ice Ages Triggered When Tropical Islands and Continents Collide

Friday, April 12, 2019

Controlling Cooling

(By Francis A. Macdonald, Nicholas L. Swanson-Hysell, Yuem Park, Lorraine Lisiecki, Oliver Jagoutz)

On million-year time scales, Earth's climate state is determined by sources and sinks of carbon to the ocean-atmosphere system. But which specific mechanisms are important in controlling the timing of glacial intervals? Macdonald et al. identify arc-continent collisions in the tropics as a primary control (see the Perspective by Hartmann). They compiled a database of Phanerozoic arc-continent collisions and the latitudinal distribution of ice sheets, showing that ice coverage was greatest when those collisions were most widespread, maximizing global weatherability.