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“Directly relating ecosystem well-being to human well-being can
make a difference, because it gives people a better sense of what's
at stake." -Marc Levy

(Images in title graphic from
Photos.com)

by Amanda Leigh Haag
October 12, 2005

Mention to someone that a little known species such as the
‘Alerce’ — a large tree native to Chile and Argentina — is
endangered, and they’re likely to not bat an eyelash. But then drop
the name of a more relatable endangered species such as, say, the
Slender Loris from Sri Lanka — a fuzzy little primate with brown
eyes that would give any teddy bear a run for its money — and it’s
likely to elicit more compassion.

Both are endangered, due in large part to habitat fragmentation
from logging and other human activities. And both are evidence of
the Earth’s dwindling natural resources, according to the Millennium
Ecosystem Assessment (MA), the first-ever global effort to take
stock of the planet’s ecosystem health. And the vital signs aren’t
looking good. Of the 24 categories of ecosystem health that were
evaluated, 15 are being seriously degraded at a rate that cannot be
sustained, said Walt Reid, director of the MA, an international,
multimillion dollar undertaking. “If we think of the planet’s
ecosystem services as a bank account that could last indefinitely if
managed wisely, we are instead spending the principal. That does
provide short-term benefits, but the long-term costs will be
significant,” said Reid. By altering the planet, be it through
deforestation, over-fishing, or degradation of land and climate
change, “we’re depleting a capital asset,” he said.

The Slender Loris (Loris tardigradus)
from Sri Lanka is assessed as endangered and is on the World
Conservation Union's 2004 Red List of Threatened Species.
Habitat fragmentation over the years has seriously reduced the
area available for this species. Between 1956 and 1993, Sri
Lanka lost more than 50% of its forest cover to human
activities, followed by a similar rate of decline in the
remaining forest cover between 1994 and 2003. (Image copyright
K.A.I. Nekaris)

The assessment represents scientists’ first global-scale attempt
at putting a price tag on the benefits that humans get from natural
systems, a concept dubbed ‘ecosystem services.’ Some of the services
studied include things that can be traded in markets, such as food
and fibers. Others have less tangible, yet equally important,
values, such as the flood control and prevention of erosion that
forests provide. The summary of the MA findings, released on March
30, 2005, was the result of four years of work by 1,300 scientists
from 95 countries.

“We looked at ecosystems through this lens of the services they
provide to people,” said Reid. “For example, we weren’t looking at
tropical forests as just a nice thing society ought to protect.
Instead, the researchers examined the economic and health benefits
that people obtain from the forest.” And what they found is cause
for grave concern. “In these utilitarian terms, the degradation of
ecosystem services represents a substantial cost,” said Reid. “We’re
losing in economic terms, and we’re losing in terms of human
health.” The study showed that not only have ecosystems been
dramatically altered, but they’ve been changed more in the last 50
years than in any comparable time period in human history.

By analyzing data from the NASA Socioeconomic Data and
Applications Center (SEDAC) at Columbia University, scientists
determined that in dryland ecosystems, such as sub-Saharan Africa
and Central Asia, land degradation through agricultural use and
climate change is closely linked to growing poverty. Drylands cover
41 percent of the Earth’s land surface and are home to more than 2
billion people — a third of the human population. Desertification,
or the expansion of drylands unsuitable for crop production, is one
of the greatest threats to human well-being, according to the
report. “Drylands, which are among the most fragile ecosystems, are
now the areas with the highest rate of population growth,” said
Reid. “Many dryland regions have become poverty traps, where a
spiral of growing poverty and environmental degradation feed on one
another.”

People living in drylands depend primarily on the productivity of
their land for their livelihoods. Crop and dairy production,
livestock, and growth of fuel and construction materials all depend
upon plant productivity, which is inextricably linked to water
availability. Overgrazing and intensive cultivation in areas that do
not have adequate levels of nutrients and water supply can lead to
greater soil loss through erosion, reduced water quality, and less
vegetation to sustain life.

People living in dryland regions depend
heavily on crop production and livestock for their
livelihoods. Overgrazing and intensive cultivation in areas
that do not have adequate levels of nutrients and water supply
can lead to greater soil loss through erosion, reduced water
quality, and less vegetation to sustain life. (Image from
Photos.com)

In addition, climate change has led to more extreme drought
cycles, according to the MA report. At least 90 percent of dryland
populations live in the developing world, making them far less
technologically able to adapt to these vulnerabilities. As a result
of the MA findings, the link between environmental degradation and
poverty is becoming the focus of considerable attention in
high-level international circles, said Reid.

Other ‘costs’ to human well-being, according to the MA study,
include soil degradation and loss of pollinating insects, loss of
water purification services, and decreased flood control, to name a
few. In addition, scientists were able to put a specific number — 2
degrees Celsius (3.6 degrees Fahrenheit) — on the amount of warming
that the planet can sustain before ecosystems begin to deteriorate.
While some northern latitude countries might actually benefit from a
warmer climate due to longer growing seasons, “once you get beyond
two degrees Celsius, there’s really no region of the world where the
benefits outweigh the costs,” said Reid.

The study also determined that degradation of fisheries resources
warrants immediate action. In most cases, both marine and freshwater
fisheries have either peaked or are being seriously over-harvested,
according to the report. The concept of over-fishing is certainly
not a new one. But by studying population data from SEDAC,
scientists participating in the MA were able to determine where
fisheries-dependent populations live and estimate the potential cost
to their livelihoods.

Deforestation in the Amazon rainforest
threatens many species of tree frogs, which are extremely
sensitive to environmental changes. (Image from Photos.com)

“A handful of earlier reports awakened people to the threats of
biodiversity loss and habitat loss, but for the most part, they have
not generated a groundswell of concern or action,” said Marc Levy,
who co-authored one of the chapters of the assessment and
coordinated the use of SEDAC data in the MA study. “But directly
relating the ecosystem well-being to human well-being can make a
difference, because it gives people a better sense of what's at
stake.”

Before the MA study, scientists had to “engage in fairly idle
guesswork” in order to determine where people live with respect to
vulnerable ecosystems, said Levy. “You can look through the
literature and find these numbers that people just pulled out of
thin air.” So researchers applied the highest-quality population
data set available known as the “Gridded Population of the
World” (GPW) and superimposed it on the countries that the MA
was studying, yielding much more precise estimates.

One challenge faced by the MA in trying to reconcile ecosystem
services with their value to human welfare was the potential for
conflict of interest, according to Levy. “The conservation folks
suspect that the poverty reduction people want to go in and build
roads to connect markets and subsidize fertilizers to help farmers
grow higher yields,” said Levy. “At the same time, the poverty
reduction people think the conservationists just don’t care about
people. But the MA brought together a lot of people who overcame
those tensions in order to work together in a framework that was
equally fair to both sides.”

Loss of
pollinating insects is among the many "costs" associated with
deteriorating ecosystem health, according to the Millennium
Ecosystem Assessment. (Image from Photos.com)

Another challenge that scientists faced over the course of the
study is that until now, almost all environmental monitoring has
taken place at the national level. There is simply no method in
place to survey environmental variables on a global scale, said
Anthony Janetos, a coordinating lead author of the study from The H.
John Heinz III Center for Science, Economics and the Environment. In
some cases, countries don’t have the financial resources to do
large-scale surveys; in other cases, it is difficult to measure
resources that no one country owns, such as fish in the ocean, said
Janetos. “It’s not like weather data, where every nation understands
that in order to do a good job understanding weather and climate,
you really need a global observation system,” said Janetos. “That’s
still a new concept for looking at ecosystems.”

But the scientists stress that the upside of the MA findings is
that many of the trends that are occurring can be reversed. The
findings weren’t the “traditional doom and gloom, ‘we’re destroying
the world and there’s nothing we can do about it,’” said Reid.
“Three of the four scenarios that we developed in this assessment
actually showed that in the next 50 years, it is possible to turn
this situation around and protect many of the ecosystem services.”

Reid noted that one exception to this is the loss of
biodiversity. The MA concluded that due to habitat loss from human
activities, a 10-15 percent extinction rate of species is expected
by the year 2050. “We’ve got to feed another 3 billion people on the
planet, so there’s going to be more loss of habitat,” said Reid.
“The end result is you still end up with a substantial amount of
species committed to extinction. It would be very hard to end the
crisis of species extinction over the next 50 years.”

Related Link(s):

Socioeconomic Data and
Applications Center (SEDAC)

Center for International
Earth Science Information Network

Millennium
Ecosystem
Assessment

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NASA Official: Jeanne Behnke
Published:
October 13, 2005
Last Updated: October 13, 2005
(To be
published in print in fall 2005)
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