Our Earth has existed for 45 million centuries; and humans for a few thousand. But this century is the first when our species is so numerous—and so demanding of energy and natural resources—that we risk collectively despoiling our planet. It’s surely an ethical imperative that we should not deny future generations the wonders and beauty of the natural world. Policy must, in the words of the Brundtland Commission, “meet the needs of the present—especially the world’s poor—without compromising the ability of future generations to meet their own needs.”
