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  • From: "Tradingpost" <tradingpost@gilanet.com>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] The state of the world? It is on the brink of disaster
  • Date: Sat, 02 Apr 2005 09:20:18 -0700


The state of the world? It is on the brink of disaster
http://news.independent.co.uk/world/science_technology/story.jsp?story=62466
7
30 March 2005

An authoritative study of the biological relationships vital to
maintaining life has found disturbing evidence of man-made degradation.
Steve Connor reports


Planet Earth stands on the cusp of disaster and people should no
longer take it for granted that their children and grandchildren will
survive in the environmentally degraded world of the 21st century. This
is not the doom-laden talk of green activists but the considered
opinion of 1,300 leading scientists from 95 countries who will today
publish a detailed assessment of the state of the world at the start of
the new millennium.

The report does not make jolly reading. The academics found that
two-thirds of the delicately-balanced ecosystems they studied have
suffered badly at the hands of man over the past 50 years.

The dryland regions of the world, which account for 41 per cent of the
earth's land surface, have been particularly badly damaged and yet this
is where the human population has grown most rapidly during the 1990s.

Slow degradation is one thing but sudden and irreversible decline is
another. The report identifies half a dozen potential "tipping points"
that could abruptly change things for the worse, with little hope of
recovery on a human timescale.

Even if slow and inexorable degradation does not lead to total
environmental collapse, the poorest people of the world are still going
to suffer the most, according to the Millennium Ecosystem Assessment,
which drew on 22 national science academies from around the world.

Walt Reid, the leader of the report's core authors, warned that unless
the international community took decisive action the future looked
bleak for the next generation. "The bottom line of this assessment is
that we are spending earth's natural capital, putting such strain on
the natural functions of earth that the ability of the planet's
ecosystems to sustain future generations can no longer be taken for
granted," Dr Reid said.

"At the same time, the assessment shows that the future really is in
our hands. We can reverse the degradation of many ecosystem services
over the next 50 years, but the changes in policy and practice required
are substantial and not currently under way," he said.

The assessment was carried out over the past three years and has been
likened to the prestigious Intergovernmental Panel on Climate Change -
set up to investigate global warming - for its expertise in the many
specialisms that make up the broad church of environmental science.

In summary, the scientists concluded that the planet had been
substantially "re-engineered" in the latter half of the 20th century
because of the pressure placed on the earth's natural resources by the
growing demands of a larger human population.

"Over the past 50 years, humans have changed ecosystems more rapidly
and extensively than at any time in human history, largely to meet
rapidly growing demands for food, fresh water, timber and fibre," the
reports says.

The full costs of this are only now becoming apparent. Some 15 of the
24 ecosystems vital for life on earth have been seriously degraded or
used unsustainably - an ecosystem being defined as a dynamic complex of
plants, animals and micro-organisms that form a functional unit with
the non-living environment in which the coexist.

The scale of the changes seen in the past few decades has been
unprecedented. Nearly one-third of the land surface is now cultivated,
with more land being converted into cropland since 1945 than in the
whole of the 18th and 19th centuries combined.

The amount of water withdrawn from rivers and lakes for industry and
agriculture has doubled since 1960 and there is now between three and
six times as much water held in man-made reservoirs as there is flowing
naturally in rivers.

Meanwhile, the amount of nitrogen and phosphorus that has been released
into the environment as a result of using farm fertilisers has doubled
in the same period . More than half of all the synthetic nitrogen
fertiliser ever used on the planet has been used since 1985.

This sudden and unprecedented release of free nitrogen and phosphorus -
important mineral nutrients for plant growth - has triggered massive
blooms of algae in the freshwater and marine environments. This is
identified as a potential "tipping point" that can suddenly destroy
entire ecosystems. "The Millennium Assessment finds that excessive
nutrient loading is one of the major problems today and will grow
significantly worse in the coming decades unless action is taken," Dr
Reid said.

"Surprisingly, though, despite a major body of monitoring information
and scientific research supporting this finding, the issue of nutrient
loading barely appears in policy discussions at global levels and only
a few countries place major emphasis on the problem.

"This issue is perhaps the area where we find the biggest 'disconnect'
between a major problem related to ecosystem services and the lack of
policy action in response," he said.

Abrupt changes are one of the most difficult things to predict yet
their impact can be devastating. But is environmental collapse
inevitable?

"Clearly, the dual trends of continuing degradation of most ecosystem
services and continuing growth in demand for these same services cannot
continue," Dr Reid said.

"But the assessment shows that over the next 50 years, the risk is not
of some global environmental collapse, but rather a risk of many local
and regional collapses in particular ecosystem services. We already see
those collapses occurring - fisheries stocks collapsing, dead zones in
the sea, land degradation undermining crop production, species
extinctions," he said.

Between 1960 and 2000, the world population doubled from three billion
to six billion. At the same time, the global economy increased more
than six-fold and the production of food and the supply of drinking
water more than doubled, with the consumption of timber products
increasing by more than half.

Meanwhile, human activity has directly affected the diversity of wild
animals and plants. There have been about 100 documented extinctions
over the past century but scientists believe that the rate at which
animals and plants are dying off is about 1,000 times higher than
natural, background levels.

"Humans are fundamentally and to a significant extent irreversibly
changing the diversity of life on earth and most of these changes
represent a loss of biodiversity," the Millennium Ecosystem Assessment
says.

The distribution of species across the world is becoming more
homogenous as some unique animals and plants die out and other, alien
species are introduced into areas in which they would not normally
live, often with devastating impact.

For example, the Baltic Sea contains 100 non-native species, of which
about one-third come from the Great Lakes of North America. Meanwhile,
a similar proportion of the 170 non-native species found in the Great
Lakes come from the Baltic.

"In other words, the species in any one region of the world are
becoming more similar to other regions.... Some 10 to 30 per cent of
mammals, birds and amphibians are currently threatened with extinction.
Genetic diversity has declined globally, particularly among cultivated
species," the report says.

Agricultural intensification, which brought about the green revolution
that helped to feed the world in the latter part of the 20th century,
has increased the tendency towards the loss of genetic diversity.
"Currently 80 per cent of wheat area in developing countries and
three-quarters of all rice planted in Asia is now planted to modern
varieties," the report says. Dr Reid said that the authors of the
assessment were most worried about the state of the earth's drylands -
an area covering 41 per cent of the land surface and home to a total of
two billion people, many of them the poorest in the world.

Drylands are areas where crop production or pasture for livestock is
severely limited by rainfall. Some 90 per cent of the world's dryland
regions occur in developing countries where the availability of fresh
water is a growing problem.

One-third of the world's people live in dryland regions that have
access to only 8 per cent of the world's renewable supply of water, the
scientists found. "We were particularly alarmed by the evidence of
strong linkages between the degradation of ecosystem services in
drylands and poverty in those regions," Dr Reid said.

"Moreover, while historically, population growth has been highest in
either urban areas or the most productive ecosystems such as cultivated
lands, this pattern changed in the 1990s and the highest percentage
rate of growth is now in drylands - ecosystems with the lowest
potential to support that growth.

"These problems of ecosystem degradation and the harm it causes for
human well-being clearly help set the stage for the conflict that we
see in many dryland regions including parts of Africa and central
Asia," he said.

Poor people living in dryland regions are at the greatest risk of
environmental collapse. Many of them already live unsustainably -
between 10 and 20 per cent of the soil in the drylands are eroded or
degraded.

"Development prospects in dryland regions of developing countries are
especially dependent on actions to slow and reverse the degradation of
ecosystems," the Millennium Assessment says.

So what can be done in a century when the human population is expected
to increase by a further 50 per cent?

The board of directors of the Millennium Assessment said in a
statement: "The overriding conclusion of this assessment is that it
lies within the power of human societies to ease the strains we are
putting on the nature services of the planet, while continuing to use
them to bring better living standards to all.

"Achieving this, however, will require radical changes in the way
nature is treated at every level of decision-making and new ways of
co-operation between government, business and civil society. The
warning signs are there for all of us to see. The future now lies in
our hands," it said.

Asked what we should do now and what we should plan to do over the next
50 years, Dr Reid replied that there must be a fundamental reappraisal
of how we view the world's natural resources. "The heart of the problem
is this: protection of nature's services is unlikely to be a priority
so long as they are perceived to be free and limitless by those using
them," Dr Reid said.

"We simply must establish policies that require natural costs to be
taken into account for all economic decisions," he added.

"There is a tremendous amount that can be done in the short term to
reduce degradation - for example, the causes of some of the most
significant problems such as fisheries collapse, climate change, and
excessive nutrient loading are clear - many countries have policies in
place that encourage excessive harvest, use of fossil fuels, or
excessive fertilisation of crops.

"But as important as these short-term fixes are, over the long term
humans must both enhance the production of many services and decrease
our consumption of others. That will require significant investments in
new technologies and significant changes in behaviour," he explained.

Many environmentalists would agree, and they would like politicians to
go much further.

"The Millennium Assessment cuts to the heart of one of the greatest
challenges facing humanity," Roger Higman, of Friends of the Earth,
said.

"That is, we cannot maintain high standards of living, let alone
relieve poverty, if we don't look after the earth's life-support
systems," Mr Higman said.

"Yet the assessment hasn't gone far enough in specifying the radical
solutions needed. At the end of the day, if we are to respect the
limits imposed by nature, and ensure the well-being of all humanity, we
must manage the global economy to produce a fairer distribution of the
earth's resources," he added.

THE TIPPING POINTS TO CATASTROPHE

NEW DISEASES

As population densities increase and living space extends into once
pristine forests, the chances of an epidemic of a new infectious agent
grows. Global travel accentuates the threat, and the emergence of Sars
and bird flu are prime examples of diseases moving from animals to
humans.

ALIEN SPECIES

The introduction of an invasive species - whether animal, plant or
microbe - can lead to a rapid change in ecosystems. Zebra mussels
introduced into North America led to the extinction of native clams and
the comb jellyfish caused havoc to 26 major fisheries species in the
Black Sea.

ALGAL BLOOMS

A build up of man-made nutrients in the environment has already led to
the threshold being reached when algae blooms. This can deprive fish
and other wildlife of oxygen as well as producing toxic substances that
are a danger to drinking water.

CORAL REEF COLLAPSE

Reefs that were dominated by corals have suddenly changed to being
dominated by algae, which have taken advantage of the increases in
nutrient levels running off from terrestrial sources. Many of Jamaica's
coral reefs have now become algal dominated.

FISHING STOCKS

Overfishing can, and has, led to a collapse in stocks. A threshold is
reached when there are too few adults to maintain a viable population.
This occurred off the east coast of Newfoundland in 1992 when its stock
of Atlantic cod vanished.

CLIMATE CHANGE

In a warmer world, local vegetation or land cover can change, causing
warming to become worse. The Sahel region of North Africa depends on
rainfall for its vegetation. Small changes in rain can result in loss
of vegetation, soil erosion and further decreases in rainfall.





  • [Livingontheland] The state of the world? It is on the brink of disaster, Tradingpost, 04/02/2005

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