Tectonics in the tropics trigger Earth's ice ages

Over the last 540 million years, the Earth has weathered three major ice ages -- periods during which global temperatures plummeted, producing extensive ice sheets and glaciers that have stretched beyond the polar caps. Now scientists have identified the likely trigger for these ice ages.

from All Top News -- ScienceDaily https://www.sciencedaily.com/releases/2019/03/190314151645.htm