Early plants linked to ancient ice ages

EXETER, England, Feb. 1 (UPI) -- The first plants to appear on earth 470 million years ago triggered a series of ice ages by causing a reduction in atmospheric carbon, British researchers said.

Scientists say the first plants to grow on land, the ancestors of mosses that grow today, had a dramatic impact on the global carbon cycle and the world's climate, a University of Exeter release said Wednesday.

Researchers said the plants extracted minerals such as calcium, magnesium, phosphorus and iron from rocks in order to grow, causing chemical weathering of the Earth's surface that pulled carbon from the atmosphere and led to a cooling of global temperatures of around 9 degrees Fahrenheit.

"For me the most important take-home message is that the invasion of the land by plants -- a pivotal time in the history of the planet -- brought about huge climate changes," Oxford University researcher Liam Dolan said.

"Our discovery emphasizes that plants have a central regulatory role in the control of climate: they did yesterday, they do today and they certainly will in the future."

However, these natural processes may be overwhelmed by human impacts, researchers said.

"Although plants are still cooling the Earth's climate by reducing atmospheric carbon levels, they cannot keep up with the speed of today's human-induced climate change," Exeter scientist Tim Lenton said.

"In fact, it would take millions of years for plants to remove current carbon emissions from the atmosphere."