Oxford, United Kingdom
Norman Myers cites economist colleagues who estimate that in the United States, $227.4 billion, or 4% of the US gross national product, is lost due to environmental damage. Globally, Myers identifies 18 "hot spot areas for biodiversity" - areas defined by their high species concentration and their high chance of habitat loss. Some 20% of all plant species are on 0.5% of the land surface and they are at extreme risk. Sub-Saharan Africa can best meet its food needs, not only by planting more crops but by planting more trees. This is because 10-20% more soil moisture could be preserved if trees were planted near growing areas; there would also be more fuel wood, and better watershed services, such as regular water flows and cleaner water.
Environmental refugees can be defined as "persons obliged to leave their traditional or established homelands for reasons of environmental problems (deforestation, desertification, floods, nuclear plant accidents, etc.), on a permanent or semi-permanent basis with little or no hope of ever returning." Myers estimates that there are currently about 25 million of these environmental refugees in the world, compared to about 17 million traditional (political) refugees. No formal accounting is currently taken of these environmental refugees, though they are the fastest growing category of refugees, and their numbers could reach 50 million by the year 2010. There could be 200 million of them in a greenhouse- warmed world. Half of present environmental refugees are in Sub- Saharan Africa.
Global warming could produce four major impacts that would create more environmental refugees: