Antarctica today can be brutally cold. For four months of the year, during polar night, there’s no sunlight at all on the world’s fifth-largest continent. Its land mass is almost entirely covered by a vast sheet of ice.
Ninety million years ago, however, things were very different. The Earth was a much hotter place, and West Antarctica was actually home to a temperate rainforest. Antarctica had a mild climate, with an average temperature of 54 degrees Fahrenheit (12°C), which sounds a lot like modern-day Seattle. Scientists know this because in 2017, they extracted a sediment core from a seabed near Pine Island Glacier, and found pollen, spores and remnants of flowering plants dating back to the Cretaceous period of 65 to 145 million years ago.
Heading to Antarctica 90 million years ago? Bring a light jacket:
- During the Cretaceous period, dinosaurs roamed the Earth and sea levels were 558 feet (170 m) higher than they are today. Temperatures in the tropics hovered around 95 degrees Fahrenheit (35°C).
- "The numerous plant remains (in the sample) indicate that the coast of West Antarctica was, back then, a dense temperate, swampy forest, similar to the forests found in New Zealand today," the researchers said.
- The world was warmer back then, in part because the carbon dioxide concentration in the atmosphere was high. The findings show how greenhouse gases (such as carbon dioxide) can cause temperatures to shoot up.