News Climate

Earth’s ancient ‘greenhouse’ conditions were hotter than thought

A 485-million-year timeline shows more extreme highs and lows than previous estimates

Artist's visualization of three Earths under icehouse or greenhouse conditions.

A new 485-million-year timeline shows how Earth’s temperatures have vacillated between periods of icehouse and greenhouse conditions. (Such extremes are creatively represented by this artist's visualization).

bischy / Getty Images Plus

By Carolyn Gramling

Over the last 485 million years, Earth has been both a lot colder and a lot hotter than once thought.

A new temperature timeline that combines geologic data with computational simulations reveals a rich, detailed and dramatic picture of the ebb and flow of icehouse and greenhouse conditions on Earth throughout this span of time, which includes most of the Phanerozoic Eon.