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 umans
have gravely altered the chemistry, biology and physical structure
of the Earth's land and water, according to the latest findings
on the "human footprint on Earth." The data showed
that nearly half of the land surface of Earth has been changed,
and some 50 'dead zones' (areas with little or no oxygen) have
developed in the Earth's coastal waters.
 The
latest findings, analyzed by Drs. Jane Lubchenco of Oregon State
University and Harold A. Mooney and Peter M. Vitousek of Stanford
University, show a "disturbing negative trend in the Earth's
ability to maintain the quality of human life," Lubchenco
stated.
Lubchenco
presented the findings at the XVI International Botanical Congress,
where more than 4,000 scientists from 100 countries are met to
discuss the latest research on plants for human survival and
improved quality of life. Among the findings are:
- Close to 50 percent of the land surface of
the planet has been transformed by humans, such as filling in
wetlands, converting tall grass prairies into cornfields, or
converting forests into urban areas.
- Humans have more than doubled the amount
of available nitrogen in the environment because of excess fertilizer
use and burning of fossil fuel.
- Rates of extinction are 100 to 1000 times
what they would be without human-induced changes in the planet.
On land, this is largely caused by habitat loss and species invasions
that are crowding out native species. In water, this is caused
by overfishing, as well.
- The year 1998 was Earth's hottest on record,
as human activities continue to increase the concentrations of
carbon dioxide and other heat-trapping gases in the atmosphere.
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Lubchenco
pointed out that while human domination of land masses is clear,
the new data also indicates a dramatic alteration of Earth's
oceans. There are now some 50 "dead zones" in the world's
coastal areas, she reported. The largest in the Western Hemisphere
is in the Gulf of Mexico, caused by excess nitrogen and phosphorus
flowing down the Mississippi River.
"We've
long thought of oceans as having an infinite ability to provide
food and other goods and services to humans. But the massive
human-wrought changes in our oceans are impairing their ability
to function as we assume they will," stated Lubchenco, a
Distinguished Professor of Zoology at Oregon State University.
"We're
degrading the water, changing our coastlines, filling in our
estuaries, and changing our rivers," Lubchenco said. "And
we're witnessing many signals of the problems that will result
from these changes, including toxic algal blooms, coral bleaching
and sudden disappearance of fish from key fisheries."
Lubchenco
reported on a number of indications of the human degradation
of the Earth's waterways:
- Half of the mangrove forests, which serve
as estuaries in the tropics, have been lost to a combination
of coastal development and conversion to aquaculture.
- Global aquaculture now accounts for more
than one-quarter of all fish consumed by humans. In the case
of shrimp and salmon -- the fastest growing segment of aquaculture
-- two to three pounds of fish are needed to grow one pound of
the raised seafood. Thus, this practice is depleting the oceans
of food for wild fish, birds, and marine mammals.
- About 3,000 species of marine life are in
transit in ballast water of ships around the world, resulting
in a serious invasion of nonnative species in our waterways.
A minor but increasing contributor to the problem is escape of
nonnative fish and plants from aquariums.
According
to Lubchenco, the global-scale changes that we have set in motion
will impair the Earth's ability to provide a wide range of services
to human life. "In addition to the direct services of food,
fiber, shelter, and medicines, many other interdependent services
are being disrupted," Lubchenco stated. For example, forests,
grassland and coral reefs contribute to flood control and climate
regulation. Mangroves, estuaries, coral reefs and kelp forests
protect shores from erosion and provide nursery areas or spawning
habitat for economically important species.
Massive changes
in the Earth's environment have far-reaching implications that
result in conflicts across political boundaries, Lubchenco said.
"Scarce resources, such as water or fishing rights, lead
to battles between states and nations. Environmental degradation
resulting in food shortages lead to civil unrest and migration
into neighboring countries," Lubchenco explained.
Increasing
economic inequities in the world raise a host of new issues,
according to the researcher. "Inhabitants of poorer nations
are less able to buy supplies such as bottled water if the water
is polluted, less able to influence important policy decisions
such as the choice of a site for a toxic waste dump," Lubchenco
said.
The groundbreaking
1997 work of Lubchenco and her colleagues documented that we
now live on a human-dominated planet, with the growth of the
human population and the amount of resources used are altering
Earth in unprecedented ways. Her current analysis updates these
findings. "The dramatic rise in our population simply exacerbates
the problems," Lubchenco stated, noting that as of July
17, 1999, there are reportedly six billion people on Earth, a
doubling in less than 40 years.
Lubchenco
did see hopeful signs in the increasing number of people who
are concerned about the environment and are willing to take action.
She noted that "it is encouraging that there is an increasing
focus on the part of the private sector, religious groups, and
individual citizens to take responsibility and undertake innovative
action."
"As inhabitants
of earth, we need to take stock of these massive changes, understand
their implications, and change our direction, " Lubchenco
said. "We are currently inattentive stewards. It is in our
best interests to be more fully engaged in ensuring our own health,
prosperity and well-being."
Lubchenco
strongly advocated additional research "so that we can make
more informed decisions about our ecosystems." Substantial
research across all disciplines is called for in a new policy
report from the National Science Board, Environmental Science
and Engineering for the 21st Century: the Role of the National
Science Foundation." Lubchenco, who chaired the Board's
Task Force on the Environment that prepared the report, equates
the need for scientists to focus on environmental research today
with the nation's past decisions to invest in science to conquer
disease, win the Cold War, or win the "space race."
The International
Botanical Congress is held only once every six years. It last
met in the United States in 1969, when it was convened in Seattle,
Washington. This year's meeting was hosted by the Missouri Botanical
Garden in St. Louis. 
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burnessc.com, at the IBC press office at (314) 611-3961 or (314) 621-4827