Humble ferns that saved the planet

Published on 01/06/2006 01:14

THE Arctic was once a balmy subtropical paradise with palm trees, alligators and an average temperature of 74F, scientists revealed yesterday.

Core samples dug from deep beneath the Arctic Ocean floor have shown that an area near the North Pole was much warmer 55 million years ago than first thought.

The research has also given scientists the idea that a simple fern may have helped prevent the Earth from turning into a blazing hothouse and allowed it to develop into the more habitable environment found on most of the planet today.

The plant formed in massive quantities in the Arctic, sucking up huge amounts of carbon dioxide, causing the tropical temperature there to drop.

The dramatic cooling altered wind patterns, ocean currents and land and ocean temperatures, and had a major impact on plant and animal life.

This natural solution to global warming took roughly one million years.

"[This plant] strongly contributed to the reduction in temperature," said Dr Hank Brinkhuis, of the department of palaeoecology at the University of Utrecht in the Netherlands.

The research, conducted by the Arctic Coring Expedition and published today in Nature magazine, examined a period 55 million years ago called the Eocene. At that time, the Earth was running a raging temperature due to the release of vast quantities of naturally occurring greenhouse gases.

Such warmth created a watery, swampy world that was inhabited by relatives of the alligator, snakes and new species of mammals.

The work has been praised by Gabriel Bowen, professor of atmospheric sciences at Purdue University in Indiana. Prof Bowen, who was not part of the team, said the research showed "there are tipping points in our [climate] system that can throw us to these conditions."

Dr Brinkhuis said the fern was like "a giant blanket" that "strongly contributed to tipping the global temperature from a hot into a cold cycle".