Human ingenuity takes on Mother Nature in ‘The Big Ratchet’
A geographer traces the innovations that have helped people overcome environmental challenges
The Big Ratchet
Ruth DeFries
Basic Books, $27.99
The second half of the 20th century witnessed “the Big Ratchet.” That’s what DeFries, an environmental geographer at Columbia University, calls the massive surge in food production that accompanied the world’s skyrocketing population growth. Her book looks back much further to survey the technological innovations that transformed humans from nomadic hunter-gatherers threatened with starvation into farmers and then into urban-dwelling specialists whose sustenance is usually produced far away by a relative few.