The remarkable fact is that, even though the earth's population has more than trebled in a century, the best measure of the scarcity of resources price has fallen virtually throughout that time for just about everything extracted from or grown in the earth, yet has risen, in the form of wages, for the one thing that has become far more abundant: people.

ECONOMIST: A Survey of the 20th Century

Noting that America must put its "fiscal house" in order, President Obama introduces the paper as America's solution to a scarcity of resources and growing complexity of challenges.

CENTERFORSECURITYPOLICY: Center For Security Policy

On one hand, sustainability creates huge opportunities by catalysing innovation and on the other, it calls for transformation in which global challenges of growth, urbanization, scarcity of natural resources and environmental change will become key strategic business drivers.

FORBES: Business Action at Rio+20