Some of the worst humanitarian crises since Rio, in countries like Haiti, Rwanda and Somalia, share as underlying causes, behind obvious political and ethnic divisions, a high and rapidly increasing density of population, extreme poverty, and a shortage of essential environmental resources, in particular a drop in per capita food production.  These may be some of the first illustrations of the consequences of exceeding the environmental capacity of a country or region (Mathews, 1994; Atwood, 1994).  The increase in environmental refugees who leave their homes because local resources can no longer support them is another symptom of this problem.  The International Conference on Population and Development in Cairo in 1994 recognized the need to integrate population, environmental and poverty eradication factors in sustainable development policies, plans and programmes (UN, 1994b).

Atwood, Brian. 1994. Atwood, Brian, head of USAID, at Nairobi news conference, quoted in Hartley, Aidan. "U.S. official says overpopulation partly caused Rwanda war". Reuter, 31 May 1994.

Mathews, Jessica. 1994. "Slow-motion security threats". Washington Post, 25 July 1994.

UN. 1994b.  Report of the International Conference on Population and Development, Cairo, 1994. A/CONF.171/13, paragraph 3.28.