|Strengthening the Fabric of Society: Population. Capacity Building for Sustainable Development (UNDP - UNFPA, 1996, 53 p.)|
There is little doubt that population factors do have an impact on resources and the environment. But more research is needed on the complicated links between various population factors - population base and growth rates, distribution patterns, migration, urbanization, etc. - and their impacts on critical natural resources such as forests, soils, freshwater, wildlife, and fish stocks, among others.
Still, a number of trends are worth noting:
- The World Conservation Union (IUCN) has declared human population growth the number one cause of species extinctions. According to IUCN, the 10 nations with the worst habitat destruction house an average of 189 people per square km., while the 10 with the most original habitat left intact have only 29 people per square km.
- As a direct result of population growth, especially in developing countries, the average amount of cropland per person is projected to decline from 0.28 hectares in 1990 to 0.17 hectares by 2025 (source: Atlas of the Environment, 1992).
- UNFPA's The State of World Population reported in 1992 that when both agricultural and nonagricultural needs are taken into account, population growth may be responsible for as much as 80 per cent of the loss of forest cover worldwide. As a result of deforestation in many poor developing countries, particularly in Africa, women are compelled to walk further and further to collect fuel-wood and fodder, reducing the time they have for more productive work (such as raising vegetables or livestock and caring for their children). In addition, the health impact of limited fuelwood supplies translates directly into poor diets and chronic ill health in many villages.
- Given future population growth projections, it has been calculated that agricultural production per person will drop significantly, from the current level of 340 kg per person per year to well under 300 kg per person per year within three to four decades.
- According to the Australian Institute of Marine Science, population growth and over-exploitation of coastal zones are responsible for the outright destruction of 10 per cent of the world's 600,000 square kilometers of coral reefs, the underwater equivalent of tropical rainforests. A further 30 per cent are imperiled and will be lost in 10-20 years, if nothing is done to save them.
- According to a study by Population Action International, in 1990, 20 countries suffered water scarcity, having less than 1000 cubic meters of water per person. Another 8 experienced occasional water stress. These 28 nations represent 335 million people. By 2025, some 48 nations, involving 3 billion people, are expected to suffer water shortages.