Computing a hard limit on growth

Agriculture now has much bigger yields than it did a century ago, but also requires vastly more energy input.Credit: Paulo Fridman/Bloomberg via Getty In 70,000 years, Homo sapiens has grown from thousands of hunter-gatherers teetering on the brink of extinction to a global population of 7.7 billion. In Growth, Vaclav Smil explains how we have peopled the planet through our growing capacity for harvesting energy from our environment: food from plants, labour from animals and energy from fossil fuels. Civilization has developed by dominating Earth's resources. It is high: polluted land, air and water, lost wilderness and rising levels of atmospheric carbon dioxide. He argues that most economic projections predict growth by ignoring the biophysical reality of limited resources.