Ruth S. DeFries, Denning Family Professor of Sustainable Development and Chair, Department of Ecology, Evolution, and Environmental Biology, Columbia University; Author, The Big Ratchet

The Big Ratchet is the story of how in the 20th century a range of technologies – from fossil fuels to scientific plant breeding to nitrogen fertilizers – combined to nearly quadruple our population in a century and to grow our food supply even faster. To some, these technologies are a sign of our greatness; to others, of our hubris. MacArthur fellow DeFries argues that the debate is the wrong one to have. Limits do exist, but every limit that has confronted us, we have surpassed. That cycle of crisis and growth is the story of our history; indeed, it is the essence of her book. Understanding it could reveal not just how we reached this point in our history, but how we might survive it.