About 55.5 million years ago, the Earth experienced a global warming event unique in its speed and magnitude - leading to what is often described as Greenhouse Earth. Scientifically, this period is known as the Palaeocene-Eocene Thermal Maximum or PETM.
With the help of ancient rocks from a Canterbury river bed, a team of palaeontologists and geochemists, led by GNS Science's Chris Hollis (pictured with Matt Huber, right, of Purdue University, Indiana) has found that the surface temperatures of the oceans surrounding New Zealand at the time exceeded 30 degrees Celsius. They presented their findings at a conference about Greenhouse Earth.
