Biodiversity A Global Outlook

1. Why is biodiversity loss a concern?

Biodiversity, ecosystem functioning, ecosystem services, and drivers of change

Biological diversity, or biodiversity, is the term given to describe the variety of life on Earth. It reflects the number, variety and variability of living organisms and how these change from one location to another and over time. Biodiversity includes diversity within species (genetic diversity), between species (species diversity), and between ecosystems (ecosystem diversity).

Ecosystems, whose functioning depends on biodiversity, provide the basic necessities of life (e.g., food, clean water and air), offer protection from natural disasters and disease (e.g., by regulating climate, floods and pests), and shape human cultures and spiritual beliefs. Besides those provisioning, regulating and cultural services they provide, ecosystems also support and maintain life processes such as biomass production and nutrient cycling (supporting services) which are essential to human well-being.

Out of the 24 ecosystem services that make direct contributions to human well-being, 15 are in decline.

The impact of humans on the natural environment is significant and growing, causing changes in biodiversity that have been more rapid in the past 50 years than at any time before in human history. As demographic pressures and consumption levels increase, biodiversity decreases, and the ability of the natural world to continue delivering the goods and services on which humanity ultimately depends may be undermined.

Biodiversity loss disrupts the functioning of ecosystems, making them more vulnerable to perturbations and less able to supply humans with needed services. The consequences are often harshest on the rural poor, who depend most immediately upon local ecosystem services for their livelihoods, and biodiversity loss poses a significant barrier to meeting the Millennium Development Goals.

To stop ecosystem degradation, the full contribution made by ecosystems to both poverty alleviation efforts and to national economies must be clearly demonstrated. More...