A widely accepted definition of sustainability is to "...meet the needs of the present without compromising the ability of future generations to meet their own needs" (Brundtland Commission, 1987). With approximately 7 billion people on Earth and a projected 9 billion by mid-century, we must find new ways of reducing resource consumption and ensuring equitable access to resources if we are to avoid dramatic environmental degradation and resource-driven political conflicts.
This is a particularly important challenge for Americans who consume more per person than any other country on the planet. If everyone on Earth (the current global population) consumed as much as the average American, we would need the resources of four more planets! We have the knowledge and technology to bring about a different future, but we also require the will to make it happen.
Sustainability is not solely about environmental stewardship, although many people associate the term with the environment. As the graphic below demonstrates, the social and economic dimensions are equally important and round out what is referred to as the "triple bottom line," a standard of ethical responsibility many corporations, institutions, and governments have adopted as a guiding principle.