Word: plant
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Dates: during 1980-1989
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Nature's diversity offers many opportunities for agriculture, especially now that genetic mapping and engineering have given biotechnology firms the potential power to improve crops by transferring genes from wild strains. According to Wilson, biotechnology can transform a plant into a "loose-leaf notebook" from which scientists can select a particular page. Among the possible results: drought- and frost-resistant crops, and natural fertilizers and pesticides...
...tropics the crucial question is how large a forest must be to sustain itself. If a park or protected area is too small to support some of its animal and plant life, the ecosystem will decline even with protection. As yet, no one knows the minimum critical size of a rain forest, but in 1979 Thomas Lovejoy, now at the Smithsonian Institution, set up a 20-year experiment with the cooperation of the Brazilian government to determine just that for the Amazon region. Among the findings: the smaller the forest, the faster the decline of insects, birds and mammals...
There were other forebodings of environmental disaster. In the U.S. it was revealed that federal weapons-making plants had recklessly and secretly littered large areas with radioactive waste. The further depletion of the atmosphere's ozone layer, which helps block cancer-causing ultraviolet rays, testified to the continued overuse of atmosphere-destroying chlorofluorocarbons emanating from such sources as spray cans and air- conditioners. Perhaps most ominous of all, the destruction of the tropical forests, home to at least half the earth's plant and animal species, continued at a rate equal to one football field a second...
Recent research has confirmed that this is more than just theory. By drilling deep into Antarctic and Arctic ice, scientists have been able to measure the amount of CO2 in air bubbles trapped in ancient layers of snow. They have also looked at fossilized plant tissues for clues as to how warm the air was during the same period. The conclusion: CO2 levels and global temperatures have risen and fallen together, over tens of thousands of years. And there is evidence from space: Mars, which has little CO2 in its atmosphere, has a surface temperature that reaches -24 degrees...
...effect, is now known to cause only half the problem. The rest comes from other gases. Chlorofluorocarbons, or CFCs, are not only destroyers of the stratosphere's ozone layer but powerful greenhouse gases as well. So are nitrogen oxides, which are pollutants spewed out of automobile exhausts and power-plant smokestacks. Another greenhouse gas is methane, the primary component of natural gas. Methane is also generated by bacteria living in the guts of cattle and termites, the muck of rice paddies and the rotting garbage in landfills. Each of these sources is fostered by human activity -- even the termites, which...