American Association for the Advancement of Science:
Population and Environment
The AAAS is the world's largest federation of scientists and engineers, with nearly 300 affiliate organizations and more than 140,000 scientists, engineers, science educators, policy makers, journalists and interested citizens worldwide. AAAS publishes Science, one of the most prestigious and frequently cited scientific journals. The Association also undertakes program activities to expand international scientific cooperation on global issues, advance science education, and shape policy issues grounded in science and technology.1
Through fossil-fuel burning and fertilizer application we have altered the natural cycles of carbon and nitrogen. The amount of nitrogen entering the cycle has more than doubled over the last century, and we now contribute 50 percent more to the nitrogen cycle than all natural sources combined. The excess is leading to the impoverishment of forest soils and forest death, and at sea to the development of toxic algal blooms and expanding "dead' zones devoid of oxygen.
By burning fossil fuels in which carbon was locked up hundreds of millions of years ago, we have increased the carbon dioxide content of the atmosphere by 30 percent over pre-industrial levels. We have boosted methane content by 145 percent over natural levels.
Through mining and processing we are releasing toxic metals into the biosphere that would otherwise have remained safely locked in stone. We are producing new synthetic chemicals, many of which may have as yet undetermined effects on other organisms.
We have thinned the ozone layer that protects life on Earth from harmful ultra-violet radiation. Most scientists agree that human activities are contributing to global warming, raising global temperatures and sea levels.
These processes affect the habitats and environmental pressures under which all species exist. As a result, we have had an incalculable effect on the Earth's biodiversity. The 484 animals and 654 plant species recorded as extinct since 1600 are only the tip of a massive iceberg [when lower level species are included the number jumps into the thousands].
The scale of our activities depends on our population numbers, our consumption and the resource or pollution impact of our technologies—and all three of these factors are still on the increase.
As we enter the third millennium, the destiny of the planet is in our hands as never before, yet they are inexperienced hands. We are modifying ecosystems and global systems faster than we can understand the changes and prepare responses to them. All the factors in this vast equation affect each other constantly. In a globalized world the elements of human activity interact with each other and with local and planetary environments.
In this unprecedented situation, the need to be fully aware of what we are doing has never been greater. We need to understand the way in which population, consumption and technology create their impact, to review that impact across the most critical fields, and to find ways of using our understanding of the links to inform policy.3
The Critical Decision Foundation highly recommends the AAAS Atlas of Population & Environment as a scientific and informed resource concerning population and the environment.
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1American Association for the Advancement of Science, AAAS Atlas of Population and Environment, (Los Angeles, CA: University of California Press, 2000) p. iv2American Association for the Advancement of Science, AAAS Atlas of Population and Environment, (Los Angeles, CA: University of California Press, 2000) pp. x and xi
3American Association for the Advancement of Science, AAAS Atlas of Population and Environment, (Los Angeles, CA: University of California Press, 2000) pp. 3 and 6