In this book Jeffrey Sachs shows us that we need a new economic paradigm–global, inclusive, cooperative, environmentally aware, and science based–because we are running up against the realities of a crowded planet. The alternative is a series of cascading threats to global well-being, all of which are solvable but potentially disastrous if left unattended. Prosperity must be maintained through new strategies for sustainable development that complement market forces, spread sustainable technologies stabilize the global population, and enable the billion poorest people to escape from the trap of extreme poverty.