The Cretaceous Thermal Maximum
The hottest sustained climate of the last quarter-billion years — crocodiles in the Arctic, no ice anywhere.
- When
- Known to
- ± 2 million years
- Era
- Cretaceous, Mesozoic
Through the Turonian, around 92 million years ago, global temperatures reach their Phanerozoic peak. Tropical sea surface temperatures approach 35 degrees Celsius, polar waters stay above freezing year-round, and there is no permanent ice at either pole. Champsosaurs and other reptiles live within the Arctic Circle, and forests grow at high latitudes in months of continuous darkness. Sea level stands perhaps 170 metres above the present, flooding a third of today's continental area. It is the clearest natural example we have of what a genuinely ice-free Earth looks like.