The persistence of glaciers...

They have survived for hundreds of thousands of years...are they really threatened now???

The most pessimistic predictions of sea level rises as ice sheets are melted by global warming may have to be scaled back as a result of an extraordinary discovery that ice persisted when the Earth was much hotter than today.

Scientists have discovered that glaciers survived for hundreds of thousands of years during an extraordinary era when crocodiles roamed the Arctic and the tropical Atlantic Ocean was as warm as human blood.

They had thought that Earth was ice free during the so called Turonian period, a "super greenhouse world" between 93.5 million and 89.3 million years ago. But now evidence has been found of hothouse glaciers that persisted by studies of tiny plankton and other marine organisms.

Large ice-sheets existed about 91 million years ago, during one of the warmest periods in the past 500 million years, an international team of scientists reports in Science.

The scientists from the UK, Germany, USA and Netherlands found evidence of an approximate 200,000 year period of widespread glaciation, with ice sheets about 60 per cent the size of the modern Antarctic ice cap.