Various studies have indicated that temperatures in the tropical Andes dropped as much as 20 degrees in the last glaciation, that snow lines advanced and vegetation retreated more than 1,000 yards down mountainsides and that the ocean near Barbados cooled by about 9 degrees.

The ocean cooled by about one degree down to depths of three thousand metres, an enormous amount of heat was extracted from the ocean.

It's far from proved that the amber bubble air is truly representative but if so, perhaps the high oxygen fell to its present levels when the oceans cooled and absorbed gas from the atmosphere.

Since there's no incoming energy from the sun, the land and the ocean can only cool down.

"And it rained and it rained for millions of years, and the volcanoes boiled and the oceans cooled, and then there was love?"

After this, the global ocean supposedly cooled and settled to such a degree that it began to subside and eventually conform to match the features seen today.

Their analysis, reported in the journal Nature, showed that sea levels fell after eruptions because the ocean cooled.

As the oceans cooled below 2 C, however, these fisheries largely moved south the Icelandic coast.