The new work presents the oldest dated evidence for hominins in Arabia, in the form of an ancient handaxe tool uncovered from the Nefud Desert.
Greenland’s conditions were once similar to those of a greenhouse. Volcanoes swelled the land, constricted seaways and gigatonnes of greenhouse gases were released into the atmosphere.
The last time global carbon dioxide levels were around 400ppm was four million years ago. On average, the world was 3℃ warmer, but in high northern latitudes, it was up to 14℃ warmer than today.
Earth’s has gone through major climate changes in the past. They happened on time scales of millions of years and triggered mass extinctions. Our emissions are changing the climate much faster.