1. Why are tropical forests important? They contain 155,000 of the 250,000 known plant species and innumerable insect and animal species. Half of all medicines prescribed are derived from wild products; the United Stated National Cancer Institute has identified more than 2,000 tropical rain forest plants with the potential to fight cancer. Rubber, timber, gums, resins and waxes, pesticides, lubricants, nuts and fruits, flavorings and dye stuffs, steroids, latexes, essential and edible oils, and bamboo are among the products affected by the depletion of the tropical forests. Back to questions

2. What are PCBs? Polychlorinated biphenyls (PCBs) were widely used before 1970 in the electrical industry as a coolant for transformers and in capacitors and other electrical devices. They caused environmental problems because they do not break down, and can spread through the water, soil, and air. They have been linked to cancer and reproductive disorders and liver function abnormalities. Government action has resulted in the control of the use, disposal, and production of PCBs in nearly all areas of the world including the United States. Back to questions

3. Is the world getting warmer? The year 1990 was the warmest year since 1880, with an average global temperature of 59.8 degreesF. Six of the seven warmer years of the 20th century have occurred during the 1980's. The average annual temperature for the contiguous United States (during 895-1990) is 52.5 F. The US began the century with cool temperatures; the 1920s through 1950s were warm; the 1960s and 1970s were cool; and the 1980s were warm. Back to questions

4. What is the status of elephants in Africa? From 1979 to 1989, Africa lost over half of its elephants (from an estimated 1.3 million to 600,00) to poachers. This led to the shift of the African elephant from threatened to endangered status in October 1989. An ivory ban took effect on January 18, 1990. Kenya now values a living elephant at $14, 375 in tourism income for every year of its life, giving it a potential lifetime value of $900,000. The ivory from the elephant would only be worth about $1,000. Back to questions

5. What is a biome? A biome is a plant and animal community that covers a large geographical area. Complex interactions of climate, geology, soil types, water resources, and latitude all determine the kinds of plants and animals that thrive in different places. Fourteen major ecological zones, called "biomes," exist over five major climatic regions and eight zoo-geographical regions. Five types of biomes are tundra, taiga, temperate deciduous forest, tropical rain forest, and desert. Back to questions