1. Research Department, Population Action International, 1300 19th Street, NW, 2nd Floor, Washington DC 20036, USA

Correspondence to: Richard P. Cincotta Correspondence and requests for materials should be addressed to R.P.C. (e-mail: Email: cincotta@popact.org).

Abstract

Biologists have identified 25 areas, called biodiversity hotspots, that are especially rich in endemic species and particularly threatened by human activities. The human population dynamics of these areas, however, are not well quantified. Here we report estimates of key demographic variables for each hotspot, and for three extensive tropical forest areas¹ that are less immediately threatened. We estimate that in 1995 more than 1.1 billion people, nearly 20% of world population, were living within the hotspots, an area covering about 12% of Earth's terrestrial surface. We estimate that the population growth rate in the hotspots (1995–2000) is 1.8% yr ^-1, substantially higher than the population growth rate of the world as a whole (1.3% yr^-1) and above that of the developing countries (1.6% yr^-1). These results suggest that substantial human-induced environmental changes are likely to continue in the hotspots and that demographic change remains an important factor in global biodiversity conservation. The results also underline the potential conservation significance of the continuing worldwide declines in human fertility and of policies and programs that influence human migration.