Two-thirds of world's resources 'used up'
Tim Radford, science editor
Wednesday March 30 2005
The human race is living beyond its means. A report
backed by 1,360 scientists from 95 countries - some
of them world leaders in their fields - today warns
that the almost two-thirds of the natural machinery
that supports life on Earth is being degraded by
human pressure.
The study contains what its authors call "a stark
warning" for the entire world. The wetlands,
forests, savannahs, estuaries, coastal fisheries and
other habitats that recycle air, water and nutrients
for all living creatures are being irretrievably
damaged. In effect, one species is now a hazard to
the other 10 million or so on the planet, and to
itself.
"Human activity is putting such a 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," it says.
The report, prepared in Washington under the
supervision of a board chaired by Robert Watson, the
British-born chief scientist at the World Bank and a
former scientific adviser to the White House, will
be launched today at the Royal Society in London. It
warns that:
· Because of human demand for food, fresh
water, timber, fibre and fuel, more land has been
claimed for agriculture in the last 60 years than in
the 18th and 19th centuries combined.
· An estimated 24% of the Earth's land surface
is now cultivated.
· Water withdrawals from lakes and rivers has
doubled in the last 40 years. Humans now use between
40% and 50% of all available freshwater running off
the land.
· At least a quarter of all fish stocks are
overharvested. In some areas, the catch is now less
than a hundredth of that before industrial fishing.
· Since 1980, about 35% of mangroves have been
lost, 20% of the world's coral reefs have been
destroyed and another 20% badly degraded.
· Deforestation and other changes could
increase the risks of malaria and cholera, and open
the way for new and so far unknown disease to
emerge.
In 1997, a team of biologists and economists tried
to put a value on the "business services" provided
by nature - the free pollination of crops, the air
conditioning provided by wild plants, the recycling of
nutrients by the oceans. They came up with an
estimate of $33 trillion, almost twice the global
gross national product for that year. But after what
today's report, Millennium Ecosystem Assessment,
calls "an unprecedented period of spending Earth's
natural bounty" it was time to check the accounts.
"That is what this assessment has done, and it is a
sobering statement with much more red than black on
the balance sheet," the scientists warn. "In many
cases, it is literally a matter of living on
borrowed time. By using up supplies of fresh
groundwater faster than they can be recharged, for
example, we are depleting assets at the expense of
our children."
Flow from rivers has been reduced dramatically. For
parts of the year, the Yellow River in China, the
Nile in Africa and the Colorado in North America dry
up before they reach the ocean. An estimated 90% of
the total weight of the ocean's large predators -
tuna, swordfish and sharks - has disappeared in
recent years. An estimated 12% of bird species, 25%
of mammals and more than 30% of all amphibians are
threatened with extinction within the next century.
Some of them are threatened by invaders.
The Baltic Sea is now home to 100 creatures from
other parts of the world, a third of them native to
the Great Lakes of America. Conversely, a third of
the 170 alien species in the Great Lakes are
originally from the Baltic.
Invaders can make dramatic changes: the arrival of
the American comb jellyfish in the Black Sea led to
the destruction of 26 commercially important stocks
of fish. Global warming and climate change, could
make it increasingly difficult for surviving species
to adapt.
A growing proportion of the world lives in cities,
exploiting advanced technology. But nature, the
scientists warn, is not something to be enjoyed at
the weekend. Conservation of natural spaces is not
just a luxury.
"These are dangerous illusions that ignore the vast
benefits of nature to the lives of 6 billion people
on the planet. We may have distanced ourselves from
nature, but we rely completely on the services it
delivers."
Copyright Guardian Newspapers Limited
Tim Radford, science editor
Wednesday March 30 2005
The human race is living beyond its means. A report
backed by 1,360 scientists from 95 countries - some
of them world leaders in their fields - today warns
that the almost two-thirds of the natural machinery
that supports life on Earth is being degraded by
human pressure.
The study contains what its authors call "a stark
warning" for the entire world. The wetlands,
forests, savannahs, estuaries, coastal fisheries and
other habitats that recycle air, water and nutrients
for all living creatures are being irretrievably
damaged. In effect, one species is now a hazard to
the other 10 million or so on the planet, and to
itself.
"Human activity is putting such a 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," it says.
The report, prepared in Washington under the
supervision of a board chaired by Robert Watson, the
British-born chief scientist at the World Bank and a
former scientific adviser to the White House, will
be launched today at the Royal Society in London. It
warns that:
· Because of human demand for food, fresh
water, timber, fibre and fuel, more land has been
claimed for agriculture in the last 60 years than in
the 18th and 19th centuries combined.
· An estimated 24% of the Earth's land surface
is now cultivated.
· Water withdrawals from lakes and rivers has
doubled in the last 40 years. Humans now use between
40% and 50% of all available freshwater running off
the land.
· At least a quarter of all fish stocks are
overharvested. In some areas, the catch is now less
than a hundredth of that before industrial fishing.
· Since 1980, about 35% of mangroves have been
lost, 20% of the world's coral reefs have been
destroyed and another 20% badly degraded.
· Deforestation and other changes could
increase the risks of malaria and cholera, and open
the way for new and so far unknown disease to
emerge.
In 1997, a team of biologists and economists tried
to put a value on the "business services" provided
by nature - the free pollination of crops, the air
conditioning provided by wild plants, the recycling of
nutrients by the oceans. They came up with an
estimate of $33 trillion, almost twice the global
gross national product for that year. But after what
today's report, Millennium Ecosystem Assessment,
calls "an unprecedented period of spending Earth's
natural bounty" it was time to check the accounts.
"That is what this assessment has done, and it is a
sobering statement with much more red than black on
the balance sheet," the scientists warn. "In many
cases, it is literally a matter of living on
borrowed time. By using up supplies of fresh
groundwater faster than they can be recharged, for
example, we are depleting assets at the expense of
our children."
Flow from rivers has been reduced dramatically. For
parts of the year, the Yellow River in China, the
Nile in Africa and the Colorado in North America dry
up before they reach the ocean. An estimated 90% of
the total weight of the ocean's large predators -
tuna, swordfish and sharks - has disappeared in
recent years. An estimated 12% of bird species, 25%
of mammals and more than 30% of all amphibians are
threatened with extinction within the next century.
Some of them are threatened by invaders.
The Baltic Sea is now home to 100 creatures from
other parts of the world, a third of them native to
the Great Lakes of America. Conversely, a third of
the 170 alien species in the Great Lakes are
originally from the Baltic.
Invaders can make dramatic changes: the arrival of
the American comb jellyfish in the Black Sea led to
the destruction of 26 commercially important stocks
of fish. Global warming and climate change, could
make it increasingly difficult for surviving species
to adapt.
A growing proportion of the world lives in cities,
exploiting advanced technology. But nature, the
scientists warn, is not something to be enjoyed at
the weekend. Conservation of natural spaces is not
just a luxury.
"These are dangerous illusions that ignore the vast
benefits of nature to the lives of 6 billion people
on the planet. We may have distanced ourselves from
nature, but we rely completely on the services it
delivers."
Copyright Guardian Newspapers Limited