Abstract
The cause of global environmental decline is clear: an immense and rapidly growing human economy. In response, environmentalists should advocate policies leading to fewer people, lower per capita consumption, and less harmful technologies. All three of these must be addressed, not just one instead of the others. That is our best remaining hope to create sustainable societies and preserve what global biodiversity remains. Sharing Earth justly with other species and protecting it for future human generations are achievable goals, but only if we recognize limits to growth, show restraint in both consumption and procreation, replace maximizing thinking with sufficiency thinking, and cultivate gratitude for what we receive from nature. Efficiency cannot take the place of ethics. Cleverness cannot take the place of wisdom. Humanity must learn to recognize and appreciate ‘enough.’