Earth & Cosmos / Earth, Climate & Environment

Ice ages discovered

Louis Agassiz argued in 1837 that ice sheets once covered Europe, revealing that Earth's climate has changed drastically.

Alpine geologists such as Jean de Charpentier and Ignaz Venetz had seen that glaciers once reached far beyond their present limits; Louis Agassiz announced in 1837 that a great Ice Age had covered much of Europe and published Études sur les glaciers in 1840. Erratic boulders, scratched rock and moraines were the evidence. The discovery that climate can change on a grand scale raised the question of what controls it, which Arrhenius and Milankovitch later took up.