The current losses of biodiversity have both direct and indirect causes. The direct mechanisms include habitat loss and fragmentation, invasion by introduced species, the over-exploitation of living resources, pollution, global climate change, and industrial agriculture and forestry. But these are not the root of the problem. Biotic impoverishment is an almost inevitable consequence of the ways in which the human species has used and misused the environment in the course of its rise to dominance.

As people awaken to the damage unsustainable development is increasingly inflicting on the web of life and the human prospect, the search for solutions must turn inward. The roots of the biodiversity crisis are not "out there" in the forest or on the savannah, but embedded in the way we live. They lie in burgeoning human numbers, the way in which the human species has progressively broadened its ecological niche and appropriated ever more of the earth's biological productivity, the excessive and unsustainable consumption of natural resources, a continuing reduction in the number of traded products from agriculture and fisheries, economic systems that fail to set a proper value on the environment, inappropriate social structures, and weaknesses in legal and institutional systems. Just as biodiversity is an essential resource for sustainable development, finding sustainable ways to live is essential if biological diversity is to be conserved.