EPIBuilding a Sustainable Future
Lester R. Brown

Chapter 8. Restoring the Earth: Protecting Plant and Animal Diversity

The two steps essential to protecting the earth’s extraordinary biological diversity are the stabilization of both the human population and the earth’s climate. If the world’s population increases to 9 billion by mid-century as projected, countless more plant and animal species may simply be crowded off the planet. If carbon dioxide levels and temperatures continue to rise, every ecosystem will change.

One reason for our goal of stabilizing population at 8 billion by 2040 is to protect the earth’s rich diversity of life. As it becomes more difficult to raise land productivity, continuing population growth will force farmers to clear ever more tropical forests in the Amazon and Congo basins and the outer islands of Indonesia. 43

Water management at a time of growing water shortages is a key to protecting fresh water and marine species. When rivers are drained dry to satisfy growing human needs for irrigation and for urban water, fish species cannot survive.

Perhaps the best known and most popular way of trying to protect plant and animal species is to create reserves. Millions of square kilometers have been set aside as parks. Indeed, some 13 percent of the earth’s land area is now included in parks and nature preserves. With more resources for enforced protection, some of these parks in developing countries that now exist only on paper could become a reality. 44

Some 20 years ago, Norman Myers and other scientists conceived the idea of biodiversity “hotspots”—areas that were especially rich biologically and thus deserving of special protection. The 34 hotspots identified once covered nearly 16 percent of the earth’s land surface but, largely because of habitat destruction, they now cover less than 3 percent. Concentrating preservation efforts in these biologically rich regions is now a common strategy among conservation groups and governments. 45

In 1973 the United States enacted the Endangered Species Act. This legislation prohibited any activities, such as clearing new land for agriculture and housing developments or draining wetlands, that would threaten an endangered species. There are numerous species in the United States, such as the bald eagle, that might now be extinct had it not been for this legislation. And now this act is seen by some conservationists as a potential leverage point in battling global warming because of the need to protect species particularly threatened by warmer temperatures, including coral and polar bears. 46

The traditional approach to protecting biological diversity by building a fence around an area and calling it a park or nature preserve is no longer sufficient. If we cannot stabilize human numbers and stabilize the climate, there is not an ecosystem on earth that we can save.

As a species, humans have an enormous influence on the habitability of the planet for the millions of other species with which we share it. This influence brings with it responsibility.

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43. U.N. Population Division, World Population Prospects: The 2006 Revision Population Database, at esa.un.org/unpp, updated 2007.

44. WWF, op. cit. note 35.

45. Conservation International, “Biodiversity Hotspots,” at www.biodiversity hotspots.org, viewed 31 July 2007.

46. U.S. Fish and Wildlife Service, “The Endangered Species Act of 1973,” at www.fws.gov/endangered, viewed 31 July 2007; Mark Clayton, “New Tool to Fight Global Warming: Endangered Species Act,” Christian Science Monitor, 7 September 2007; U.S. Fish and Wildlife Service-Alaska, “Polar Bear Conservation Issues,” at alaska.fws.gov/ fisheries/mmm/polarbear/issues.htm, updated 5 October 2007.


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