While forests die as part of a natural process, humans
destroy about 27 hectares (67 acres) of forest every minute,
according to the U.N.'s Food and Agriculture Organization.
Those minutes and hectares add up fast. Over the course of
a year, our planet loses some 14 million hectares (35 million
acres) of forest. That's an area roughly the size of New York
State. The World Resources Institute estimates that about
80 percent of the Earth's original forest cover has been destroyed
or degraded.
Source: USDA, Jeff Vanuga |
Why do we tear down trees? The reasons are complex,
of course, but they grow out of two simple facts: People need
1) space and 2) ways to support themselves. Historically, we
lose forests when people decide to use the land for other purposes.
A few centuries ago, for example, Europeans who settled in the
eastern U.S. needed to grow food and raise animals. But the
only way they could create the vast farmland they needed was
to chop down huge forests. To them, the forests seemed endless,
and no one worried about hurting the environment.
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Compare the loss of trees (red areas) in Kenya's Immenti Forest Reserve. These satellite images reflect the changes that have occurred in just 5 years due to the illegal conversion of forested land to cropland (see diagram below).
Source: United Nations Environment Programme |
HARD REALITIES IN THE RAINFOREST
Today's wealthy countries have huge appetites for lumber,
paper, and other wood products. Not surprisingly, then, people
in struggling nations race to turn their rainforests into
cash. (The U.S. is the world's leading importer of forest
products.) Clearing forests also opens up land on which swelling
populations can live, farm, and raise livestock.
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In the 1990s,
almost 70 percent of deforested land was changed to land
for agriculture. In Latin America, the farms were large
scale. In Africa, forest was converted mostly to small
farms. (Pan tropical refers to overall data from satellite
images.)
Source: United Nations Environment Programme |
Everyone wins, right? That's the theory. Reality, though,
serves up cruel ironies: Decisions about destroying forests
are often made without taking the well being of local people
into account. And profits frequently go to the local bigwigs
or to foreign corporations.
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Illegal, uncontrolled
logging in Burma leads to soil erosion, contributing to
food shortages and malnutrition.
Source: UNEP |
A further irony is that rainforests make poor farmland. Those
lush jungles survived because their intricate ecosystems included
organisms that could recycle the nutrients in dead animals
and plants. But stripped of its green cover, the soil is thin
and barren. Farmers often abandon the land after a few seasons.
Ranchers tend to last about a decade. Then people move on
to new places, where the cycle starts all over. And the former
rainforest becomes a wasteland. Soil erodes. The original
tree canopy never grows back. Everyone loses.
Does this need to happen? No. A recent study shows that if
the rainforest were left standing, its resources would yield
far more money than could ever be earned from lumber and agricultural
products, if the forest were cut down.
WHY DEFORESTATION MATTERS Well,
so what? Don't countries have the right to decide how to treat
their own land, especially since the greatest impact-good
and bad-is on local people?
The problem is, deforestation affects people all over the
world. Here are four major ways:
- Trees breathe in and store carbon
dioxide, one of the major greenhouse
gases. Fewer trees lead to more carbon dioxide in
the atmosphere, boosting the likelihood of global warming.
- Scientists estimate that 70 percent of all land-dwelling
species live in rainforests. Wiping out such biodiversity
also means wiping out irreplaceable sources of food and
medicine. Did you know that more
than 25 percent of Americans' prescription drugs come
from plant substances—including species found
only in the rainforest?
- Trees release huge amounts of water vapor, a process
called transpiration.
This water vapor later condenses and returns to the surface
as rain or snow. Destroying forests, then, cuts the amount
of water vapor released into the atmosphere. That in turn
can mean smaller amounts of rain and snow. Studies in
Ghana and Nigeria, for example, reveal links between rainforest
destruction
and chronic drought. That's bad news for those who
grow food—or eat it.
- Clearing forests in some regions could spark outbreaks
of infectious
diseases. Pathogens,
or organisms that cause illness, may spread more easily.
And disease vectors
might behave in new ways.
Click on the names below to learn more about how cutting
down trees can give rise to disease.
Deforestation, you can see, really is everyone's problem.
So what can we do about it? The key challenge is to help developing
countries find Earth-friendly strategies for survival. How?
Here are some ideas:
- Join or contribute to groups that purchase and preserve
forests, and educate the public.
- Buy nuts, spices, oils, furniture and wood products, and
other items that can be harvested responsibly from rainforests.
- Boycott food raised on deforested land.
- Encourage leaders to cooperate internationally.
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Scientists have noticed a pattern: Outbreaks
of deadly disease often erupt when people
wipe out forests. Why?
