How ancient Scottish rocks throw 'snowball Earth' theory up in the air

Researchers discover rare periods of a few thousands years when climate unexpectedly awoke from slumberDuring the "snowball Earth" period about 700m years ago, Earth's climate shut down. The planet was encased in ice and insulated from seasonal variations: spring, summer, autumn and winter all stopped. Or at least that was the theory.Recent examination of some ancient rocks from the west coast of Scotland have now overturned that thinking, suggesting there were periods during snowball Earth when the climate woke up. Continue reading...