Moss may have caused the first ice age

The arrival of the first simple plants on land more than 470 million years ago may have triggered the first ice age. The ice age was preceded by a rapid drop in carbon dioxide levels, but the cause was not fully understood.

The first land plants were non-vascular plants, such as moss, which lack roots. Vascular plants with deep roots can suck nutrients out of rock. This leaves rocks chemically altered to the point that they react with carbon dioxide and suck it out of the atmosphere. But it was thought non-vascular plants didn’t have the same impact on rocks.

Researchers tested the impact of common moss on granite, finding that non-vascular plants can inflict as much damage on rock as vascular plants. This might have caused the rapid drop in carbon levels during the Ordovician era.

In addition, the moss can release phosophorous from rock into the ocean. This may have triggered algal blooms and could explain the mass extinction of marine life which occurred at the end of Ordovician era.

Read more at University of Exeter