permaculture

["Lawrence F. London, Jr." <lfl@intrex.net>]

<http://news.bbc.co.uk/1/hi/sci/tech/4826262.stm>
Last Updated: Monday, 20 March 2006, 17:06 GMT
Life's diversity 'being depleted'
By Tim Hirsch
BBC News Environment Correspondent

Panda (Getty Images)
Abundance and variety continue to fall across the planet
Virtually all indicators of the likely future for the diversity of life on Earth are heading in the wrong direction, a 
major new report says.

The Global Biodiversity Outlook (GBO) is published as national delegates gather in Brazil under the UN Convention on 
Biological Diversity.

The Convention commits governments to slow the decline in the richness of 
living systems by 2010.

The GBO says "unprecedented efforts" will be needed to achieve this aim.

It sets out 15 indicators of progress towards the 2010 target, ranging from trends in the extent of wildlife habitats to 
the build-up of nutrients such as nitrogen which can harm aquatic life.

Only one of the 15 - the area of the world's surface officially protected for wildlife - is moving in the right 
direction for biodiversity.

        
GLOBAL ECOLOGIAL FOOTPRINT
Human footprint (Unep)
Resource demand challenges Earth's regeneration capacity
Fish are harvested faster than their natural replacement rate
Water is being withdrawn faster than aquifers are replenished
The biosphere takes one year and nearly three months to renew what humanity 
exploits in one year, on this analysis
Even here, however, most areas still fall far short of targets to protect 10% of each region with distinctive 
combinations of species.

The other indicators point to an accelerating decline, which has seen the rates of species extinctions surge to their 
highest levels since the demise of the dinosaurs 65 million years ago.

Forests continue to be lost at a rate of six million hectares a year - that's about four times the size of the English 
county of Yorkshire - and similar trends are noted for marine and coastal ecosystems such as coral reefs, kelp beds and 
mangrove forests.

The abundance and variety of species continue to fall across the planet, according to an index measuring the percentage 
of species with good prospects for survival; bird variety is on the decline in every ecosystem type from the oceans to 
the forests.

Less complete indications are available for other groups of animals and plants, but it is feared they would show a 
similar picture.

Within reach

The report stresses that despite the gloomy trends, the target set by the Convention - involving a stabilisation, not a 
reversal of these losses - is still within reach.

"Meeting the 2010 target is a considerable challenge, but by no means an 
impossible one," the GBO notes.

"Unprecedented additional efforts are needed, and these must be squarely focused on addressing the main drivers of 
biodiversity loss."

These "drivers" are identified as:

    * the loss of habitat, largely through the expansion of agriculture
    * climate change
    * the introduction of alien species which can badly disrupt ecosystems 
after being carried across the world, often
      accidentally in ship ballast tanks
    * over-exploitation of wildlife, for example through overfishing
    * the build-up of nutrients through chemical fertilisers, sewage and air 
pollution

The great challenge in meeting the biodiversity target comes in the fact that these pressures are currently projected to 
remain constant or to accelerate in the near future - so slowing the extinction slide would involve major changes over 
wide areas of human activity.

In the jargon, this requires "mainstreaming" of biodiversity concerns into areas of policy well beyond the remit of the 
environmental officials and ministers from more than 180 countries meeting in the Brazilian city of Curitiba over the 
next fortnight.

Unless they can convince their colleagues responsible for agriculture, energy, world trade and industry that losing 
biodiversity threatens people and economies across the planet, the decisions and pledges they make will do little to 
reverse the trends identified in this report.

ECONOMIC BENEFITS UNDER ALTERNATIVE MANAGEMENT PRACTICES
Alternative management practice (MA)
* The full economic value of sustainable ecosystem management is rarely 
recognised and frequently ignored
* Converting mangroves to shrimp farms brings immediate monetary benefit but 
diminishes other important 'services'
* For example, mangroves provide timber, boost fisheries and provide storm 
protection - all of value to a much wider
  community
* If these 'externalities' are properly taken into account, the benefits of 
ecosystem conversion look weaker