“Imagine the Earth almost completely frozen over,” said the study’s lead author, ARC Future Fellow Dr Adriana Dutkiewicz. “That’s just what happened about 700 million years ago; the planet was blanketed in ice from poles to equator and temperatures plunged. However, just what caused this has been an open question.

“We now think we have cracked the mystery: historically low volcanic carbon dioxide emissions, aided by weathering of a large pile of volcanic rocks in what is now Canada; a process that absorbs atmospheric carbon dioxide.”