Humans driving extinction crisis, says UN

Posted: 27 March 2006

The growing human population of 6.5 billion is undermining the environment for animals and plants via pollution, expanding cities, deforestation, introduction of 'alien species' and global warming, according to a UN report issued by the Secretariat of the 1992 Convention on Biological Diversity (CBD) at a meeting held in Curitiba, Brazil from March 20-31.

Humans contribute more reactive nitrogen to ecosystems globally than do all natural processes combined, says the report. The rate and risk of alien species introductions have increased significantly in the recent past, and will continue to rise as a result of increased travel, trade and tourism.

Yellow-eared Parrot, Critically Endangered. © Fundacion ProAves (c/o Paul Salaman)
Yellow-eared Parrot, Critically Endangered. © Fundacion ProAves (c/o Paul Salaman)
The Yellow-eared Parrot (Ognorhynchus icterotis) is Critically Endangered because its known range is extremely small. Suitable habitat continues to be lost and degraded. Currently, it is known only in the Central Andes of Colombia.© Fundacion ProAves (c/o Paul Salaman)
Overall, unsustainable consumption continues, as indicated by the human species' growing global ecological footprint. The global demand for resources now exceeds the biological capacity of the Earth to renew these resources by some 20 per cent.

The Global Biodiversity Outlook 2 report is meant to provide an assessment of progress towards the 2010 biodiversity target set in 2002. Other highlights of the report include:

  • Deforestation, mainly through conversion of forests to agricultural land, continues at an alarmingly high rate. The loss of primary forest since 2000 has been estimated at 6 million hectares annually. Coastal and marine ecosystems have been heavily impacted by human activities, with degradation leading to a reduced coverage of kelp forests, seagrasses and corals.

  • In the Caribbean, average hard coral cover declined from about 50 per cent to 10 per cent in the last three decades. Some 35 per cent of mangroves have been lost in the last two decades, in countries for which adequate data are available.

  • Trends of some 3,000 wild populations of species show a consistent decline in average species abundance of about 40 per cent between 1970 and 2000; inland water species declined by 50 per cent, while marine and terrestrial species both declined by around 30 per cent.

  • Studies of amphibians globally, African mammals, birds in agricultural lands, British butterflies, Caribbean and Indo-Pacific corals, and commonly harvested fish species show declines in the majority of species assessed.

  • More species are becoming threatened with extinction. The status of bird species show a continuing deterioration over the last two decades and preliminary findings for other major groups, such as amphibians and mammals, indicate that the situation is worse than for birds.

  • Forests and other natural habitats are increasingly fragmented, affecting their ability to maintain biodiversity and deliver ecosystem goods and services. Within the 292 large river systems assessed, for instance, only 12 per cent of river-basin area was unaffected by dam-based impacts.

  • The intensification of fishing has led to the decline in large high-value fishes, such as tuna, cod, sea bass and swordfish, which are high up in the food chain. In the North Atlantic, the number of large fish has declined by two-thirds in the last 50 years.
Denuded mountains, The Philippines. Photo: Henrylito Tacio
Denuded mountains, The Philippines. Photo: Henrylito Tacio
Denuded mountains, The Philippines© Henrylito Tacio
"In effect, we are currently responsible for the sixth major extinction event in the history of earth, and the greatest since the dinosaurs disappeared, 65 million years ago," say the authors of the 92-page report. Apart from the disappearance of the dinosaurs, the other "Big Five" extinctions were about 205, 250, 375 and 440 million years ago.

"Unprecedented additional efforts will be needed to achieve the 2010 biodiversity target at national, regional and global levels," the report concludes bleakly.

See also the Reuter report: Sixth great extinction is now upon us

For more information on the Global Biodiversity Outlook 2 report, or to download the complete report, click here.