Thanks to global warming, we have Machu Picchu

Since it's been a particularly cold and rainy summer, I appreciate even more the benefits that can accrue from global warming.  Before this article in the London Times, I had no idea that  the rise of the Inca civilization is attributed to a 400-year-period of warm weather.

Climate study puts Incas’ success down to 400 years of warm weather

According to new research, an increase in temperature of several degrees between AD1100 and 1533 allowed vast areas of mountain land to be used for agriculture for the first time. This fuelled the territorial expansion of the Incas, which at its peak stretched from the modern Colombian border to the middle of Chile.

“Yes, they were highly organised, and they had a sophisticated hierarchical system, but it wouldn’t have counted a jot without being underpinned by the warming of the climate,” says Dr Alex Chepstow-Lusty, a palaeo-ecologist from the French Institute for Andean Studies in Lima, Peru.

As the treeline moved higher up the mountains, the Incas re-sculpted their landscape to maximise agricultural productivity. They carved terraces into the mountainsides and developed a complex system of canals to irrigate the land.

“It was the perfect incubator for the expansion of a civilisation,”