A satellite image of a swirling hurricane Men with gas masks and protective suits on The planetary rover Sojourner A large group of refugees huddled together

 HUMAN
 IMPACT

Floods and
 Dams

Ozone and
 Pollution

Deforestation
 and
 Desertification

Overpopulation



British economist Thomas Malthus in 1798 proposed the unsettling theory that population growth would outrun the ability to produce food. This, he said, would lead to war, famine, disease, and other calamities.

Since Malthus’s time, technology has struggled to keep up with burgeoning populations. The introduction of machinery to farming vastly improved crop yields. Further leaps in production came from the development and use of fertilizers as well as new understandings of plant diseases, the use of genetics to develop new strains, and the use of pesticides to cut losses due to insects, fungi, and other parasites. At sea, large ships with heavy gear prowl in search of fish.

The challenge remains to find ever more efficient and less environmentally harmful ways to feed the world. Better management of soil—for example, by rotating crops—can reduce the need to clear more woodland for agriculture. Contour plowing diminishes water-polluting runoff. Some governments have limited or banned the use of DDT as an insecticide because of its cumulative effects in the food chain.

As the Earth’s population continues to mushroom, can ways be found to manage natural resources without causing ecological collapse? The most successful efforts are almost always the result of cooperation between government and industry. But as is true with all government regulation, laws tend to be effective only when they are understood and supported by the people who are affected: both producers and consumers.

In places where these vital conditions do not exist the environment suffers, and ultimately, so do people around the world.

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image: Effects of overpopulation
VIDEO:

Using NASA’s remote sensing technology farmers are able take corrective action before it’s too late.

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VIDEO:

NASA uses remote sensing technology to develop industry partnerships with California wineries.

Real Media Player


FAST FACT:

An estimated 5 million people were alive in 8000 B.C., a little more than the present population of Papua New guinea. Today the world’s population is approximately 6 billion people.

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