With a stable climate, our early ancestors had the time to improve on their tools; heavy flint hand axes gave way to lighter blades attached to wooden handles.
There’s a child’s toy called “Etch a Sketch.” Perhaps you remember it? You use it to make intricate designs on a screen, then give the screen a shake — and your drawings disappear.
That’s pretty much what happened to Northern Europe and the British Isles during the last ice age. For the past 10,000 years or so, Britain’s climate has been welcoming and it has allowed humans to comfortably settle in. But during the last ice age, these areas were uninhabitable.
“It’s very cold, [and] it’s treeless,” says Clive Gamble, an archaeologist at the University of London. “In some places, it’s described as polar desert. It’s not somewhere you’d want to be.”
There were early humans in Britain before the ice arrived, but when it got too cold, they fled to Southern France and Spain.
See also the magnificent Ring O’ Brodgar