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Independent
Quarter of mammals faced with extinction
By Steve Connor Science Editor
21 May 2002
Almost a quarter of the world's mammals face extinction within 30 years,
a United Nations study on the state of the global environment will
announce tomorrow.
Scientists who contributed to the report have identified 11,046 species
of plants and animals that are endangered. These include 1,130 mammals –
24 per cent of the total – and 12 per cent, or 1,183 species of birds.
The list of the critically endangered ranges from the well-publicised,
such as the black rhino and Siberian tiger, to the less well known, such
as the Amur leopard of Asia, the short-tailed chinchilla of South
America and the Philippine eagle.
Human activities, notably the destruction of habitats and the
introduction of alien species from one part of the world into another,
are identified as the main cause of this loss in "biodiversity".
The researchers who helped to prepare the Global Environment Outlook-3
(Geo-3) report of the United Nations Environment Programme (Unep) also
identify 5,611 species of plants that are facing extinction. They point
out that the true figure is likely to be far higher given that only 4
per cent of the known plant species have been properly evaluated.
The report, which reviews the past 30 years of environmental degradation
as well as looking forward to the next 30 years, is understood to say
that all the factors that have led to the extinction of species in
recent decades continue to operate with "ever- increasing" intensity.
Although Geo-3 covers a wide area of concerns, from the exploitation of
land to water pollution, it identifies the need to conserve the Earth's
biodiversity as a vital element in the drive towards tackling growing
poverty – the theme of this summer's World Summit on Sustainable
Development in Johannesburg.
Threats to life on Earth include exploitation of natural resources,
pollution, habitat destruction, the introduction of alien species and
global climate change, the scientists who advised Unep said. They
believe that the loss of habitats by human encroachment is largely
responsible for the predicament facing 89 per cent of threatened birds,
83 per cent of threatened mammals and 91 per cent of endangered plants.
Unep has identified alien invasive species as the second major threat,
affecting about 30 per cent of threatened birds and 15 per cent of
threatened plants.
Geo-3 aims to address the factors contributing to the environmental
degradation of the Earth, whether they affect land, air or water. It is
expected to say that many problems can be rectified if governments
implement the treaties and conventions passed since the Rio Earth Summit
of 1992 – including the Kyoto protocol on climate change and the
Convention on Biodiversity.
Mark Collins, the director of Unep's World Conservation Monitoring
Centre in Cambridge, said: "I think if we are able to knuckle down to
carry out the measures that have been proposed since Rio there is cause
for optimism."
Nevertheless, the Geo-3 report identifies a number of problems– not
least global warming – that appear to be growing. In addition, human
poverty is increasing, which is aggravating huge losses in biodiversity
and "has to be addressed", Dr Collins said.
Klaus Töpfer, the executive director of Unep, will launch the report in
London with Margaret Beckett, the Secretary of State for the
Environment, Food and Rural Affairs.
How one creature drives so many species to extinction
Scores of animals and plants are being driven out of existence each year
- and scientists say that mankind is almost always to blame
By Steve Connor Science Editor
21 May 2002
Internal links
Quarter of mammals faced with extinction
How one creature drives so many species to extinction
Iceland walks out of whaling summit
Planet Earth is going through its sixth and probably its most
devastating period of mass extinction with scores, and possibly hundreds
of species of animals and plants dying out each year. But unlike the
previous five extinction waves, this time the culprit is just another
lifeform, Homo sapiens.
A United Nations report on the environment, to be published tomorrow,
will highlight the scale of a problem many conservationists believe is
likely to rapidly worsen over 30 years as wildlife congregations are
destroyed or invaded by a less diverse range of species.
Some scientists believe the "sixth wave" of mass extinction is between
1,000 and 10,000 times greater than the normal "background" rate at
which species are lost naturally.
Such a dramatic fall in biological diversity is identified as one of the
most pressing problems facing humanity, by the scientists who
contributed to the Global Environment Outlook-3 (Geo-3) report of the
United Nations Environment Programme (Unep).
The report will identify some 11,046 species of plants and animals known
to face a high risk of extinction, including 1,130 mammals – 24 per cent
of the total – and 12 per cent, or 1,183 species of birds.
Human activities, from habitat destruction to the introduction of alien
species from one area to another, are listed as the main causes of this
dramatic loss in biodiversity. In the report, scientists also identify
5,611 species of plants known to be on the verge of extinction. They say
the true figure is likely to be far higher, given that only 4 per cent
of the world's known plant species have been properly evaluated.
The Geo-3 report covers almost every aspect of environmental
degradation, from forest destruction to water pollution. It is designed
to set the framework for the world summit on sustainable development to
be held this summer in Johannesburg.
Geo-3 looks back on the past 30 years of environmental degradation,
since the 1972 Stockholm conference on the human environment, to assess
the likely prospects for the next 30. It is likely to warn that many of
the factors that led to the extinction of species in recent decades
continue to operate with "ever-increasing" intensity.
Serious threats to life on Earth are over-exploitation of natural
resources, pollution, habitat destruction, the introduction of alien
species and global climate change, say the scientists who advised Unep.
They identify the loss of habitats by human encroachment as one of the
most pervasive threats to wildlife. Habitat loss and fragmentation of
breeding grounds are behind the precarious predicament of 89 per cent of
threatened birds, 83 per cent of threatened mammals and 91 per cent of
endangered plants, the Unep scientists say.
In addition to growing poverty and climate change caused by global
warming, Unep has identified alien invasive species as another serious
threat to biodiversity, affecting 30 per cent of threatened birds and 15
per cent of threatened plants.
The black rat, which since 1800 has stowed away on ships sailing to the
remotest corners of the world, is held responsible for the biggest
slaughter of birds, especially those on uninhabited islands.
Another of man's hitchhikers has caused havoc to native wildlife from
Hawaii to the Seychelles and Zanzibar. The crazy ant, so called because
of its frenetic movements, killed three million crabs in 18 months on
Christmas Island alone.
A host of other invasive aliens have also inflicted enormous
environmental and economic damage throughout the world. The list
includes the brown tree snake, the small Indian mongoose, the Nile
perch, the strawberry guava, the water hyacinth, the zebra mussel and
the brushtail possum.
Several species of animals and plants in Britain are threatened by a
similar invasion of aliens. The water vole is being killed off by the
American mink, the eggs of rare wading birds nesting in the Outer
Hebrides are being eaten by hedgehogs introduced from the mainland, and
the wetland habitats of the Norfolk Broads suffered decades of
destruction by the coypu, a South American rodent.
Jeff McNeely, chief scientist at the International Union for
Conservation of Nature in Geneva, said the next 30 years could be the
defining moment for life on Earth. Either we can finally recognise the
problems and do something about them, or we do not, he said.
"It could go either way. It could be a golden age of nature
conservation, or it could be a disaster scenario. If we assume a
doomsday scenario then we're going to live in a greatly oversimplified
world.
"Most of the remaining species are going to be widely dispersed and
cosmopolitan. We will have lost many of the large mammals and birds, and
life in general will be more homogeneous, with a smaller capacity to
adapt to a changing environment."
Within the next 30 years, if the biodiversity crisis is not addressed,
it is likely that the last tiger, rhinoceros, Asian elephant, cheetah
and mountain gorilla will have been lost in the wild, Dr McNeely added.
Often it is the well-known animals and plants which are at greatest
risk. The Chinese alligator is the most endangered crocodilian, with
only 150 individuals in the wild. Half of the world's insect-eating
pitcher plants are threatened and one, the green pitcher plant, is
critically endangered because of the loss of its wetland habitat.
Scientists have identified and named about 1.5 million species but they
believe that between 5 million and 15 million species have yet to be
formally classified. It is now generally assumed that many unnamed
animals, plants and micro-organisms are going extinct before they are
even known to science.
Lord May, an Oxford zoologist, believes present extinction rates are
likely to increase further over the next century. He said: "This
represents a sixth great wave of extinction, fully compatible with the
big five mass extinctions of the geological past, but different in that
it results from the activities of a single other species rather than
from external environmental changes."
This catalogue of extinction is in danger of going unrecorded as fewer
scientists are being trained in the field of taxonomy, the science of
systematic classification.
Last week, the House of Lords Select Committee on Science and Technology
warned that a shortage of taxonomists and underfunding of the research
centres for systematic biology was jeopardising efforts to protect
wildlife. How can biodiversity be protected if no one is recording what
is there? "We have a cultural and moral obligation, as well as a
pragmatic economic need, to record and, as far as possible, conserve the
diversity of life with which we share the planet," the committee said.
The Natural History Museum and Kew Gardens in London are two
world-reknowned centres for animal and plant taxonomy yet the committee
found that both were finding it difficult to provide a service because
of financial constraints. "It has also placed the reference collections
of specimens comprising a wide range of biodiversity, which are housed
in these institutions, at considerable risk," the committee added.
Professor Paul Henderson, director of science at the Natural History
Museum, said systematics and the description of species was critical to
the preservation of animals and plants, and the key to economic
prosperity for many of the poorer nations in the world. He said it was
at the heart of the sustainable development theme of the forthcoming
world summit.
"We helped to identify the screw-worm when it invaded African livestock
from South America," Professor Henderson said. "Without recognising it
early on, it would have wreaked havoc with enormous economic
consequences,"
Yet being able to name species will not, in itself, stop the inexorable
decline, he said. "In 30 years? We'll still be heading for very fast
rates of extinction comparable to today simply because we're not doing
anything about it," the professor said. "I have to be a bit gloomy on
the 30-year time-scale. There's not been very much action to justify
being optimistic."
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