Real numbers

Biodiversity and population growth

How important is population growth to current global biodiversity loss? Although there is no credible numerical answer to that question, the bulk of the evidence suggests that population growth is and has been an important underlying cause of biodiversity

We recently examined rates of population growth (including migration) and density in 25 "biodiversity hotspots," areas identified by Conservation International as especially rich in endemic species but which have experienced dramatic reductions in the amount of original vegetation remaining within their boundaries. Nearly one-fifth of humanity (more than 1.1 billion people) lives within the hotspot boundaries, despite the fact they enclose only one-eighth of the planet's habitable land area, according to 1995 population data. In all, 16 of the 25 hotspots are more densely populated than the world as a whole, and 19 have population growth rates faster than the world average. In addition, more than 75 million people, or 1.3 percent of the world's population, now live within the three major tropical wilderness areas (Upper Amazonia and Guyana Shield in South America, the Congo River Basin of central Africa, and New Guinea and adjacent Melanesia).