Earth's Species Feel The Squeeze

[Guest guest]

Earth's species feel the squeeze

By Jonathan Amos

BBC News science reporter

 

Source >

http://news.bbc.co.uk/1/hi/sci/tech/4563499.stm

 

 

 

" Unprecedented " effort is required to slow

biodiversity loss

If we continue with current rates of species

extinction, we will have no chance of rolling back

poverty and the lives of all humans will be

diminished.

 

That is the stark warning to come out of the

Millennium Ecosystem Assessment (MA), the most

comprehensive audit of the health of our planet to

date.

 

Organisms are disappearing at something like 100 to

1,000 times the " background levels " seen in the fossil

record.

 

Scientists warn that removing so many species puts our

own existence at risk.

 

It will certainly make it much harder to lift the

world's poor out of hardship given that these people

are often the most vulnerable to ecosystem

degradation, the researchers say.

 

The message is written large in Ecosystems and Human

Well-being: the Biodiversity Synthesis Report.

 

Biodiversity and human well-being just cannot be

separated

 

Dr Kaveh Zahedi, World Conservation Monitoring Centre

It is the latest in a series of detailed documents to

come out of the MA, a remarkable tome drawn up by

1,300 researchers from 95 nations over four years.

 

The MA pulls together the current state of knowledge

and in its latest release this week focuses

specifically on biodiversity and the likely impacts

its continued loss will have on human society.

 

Even faster

 

In one sense, and precisely because it is a synthesis,

the new document contains few surprises. It is,

nonetheless, a startling - and depressing - read.

 

MA BIODIVERSITY SYNTHESIS

The last 50 years have seen the biggest biodiversity

upheaval in human history

Over half the world's biomes (vegetation types) have

experienced about 20-50% conversion to human use

The rates of change have been greatest in tropical and

sub-tropical dry forests

Some 35% of mangroves and about 20% of corals have

gone

Across a range of taxonomic groups, species are in

decline

A third of all amphibians, a fifth of mammals and an

eighth of all birds are now threatened with

extinction. It is thought 90% of the large predatory

fish in the oceans have gone since the beginning of

industrial trawling.

 

And these are just the vertebrates - the species we

know most about. Ninety percent of species, maybe

more, have not even been catalogued by science yet.

 

" Changes in biodiversity were more rapid in the last

50 years than at any time in human history, " said Dr

Georgina Mace, the director of science at the

Institute of Zoology, in London, UK, and an MA

synthesis team member.

 

" And when you look to the future, to various

projections and scenarios, we expect those changes to

continue and in some circumstances to accelerate.

 

" Future models are very uncertain but all of them tell

us that as we move into the next 100 years, we'll be

seeing extinction rates that are a thousand to 10,000

times those in the fossil record. "

 

'Invisible services'

 

One feature that sets the MA apart from previous

projects of its kind is the way it defines ecosystems

in terms of the " services " , or benefits, that people

get from them.

 

Some of these services are obvious - they are

" provisional " : timber for building; fish for food;

fibres to make clothes.

 

 

Most industrial fisheries are either fully or

overexploited

At another level, these services are largely unseen -

the recycling of nutrients, pollination and seed

dispersal, climate control, the purification of water

and air - but without these " support " and " regulating "

systems, life on Earth would soon collapse.

 

And although we may be some distance away from an " end

scenario " , there is no doubt the rapid expansion of

the human population and its high consumption of

natural resources have taken a heavy toll on

ecosystems and the organisms that inhabit them.

 

" Biodiversity and human well-being just cannot be

separated, " said Dr Kaveh Zahedi, the officer in

charge of the Unep World Conservation Monitoring

Centre in Cambridge, UK.

 

" We are befitting from a whole range of services that

up until now have almost been invisible; we haven't

considered them. And then they suddenly pop up on our

radar screens - we have a tragedy in Asia with a

tsunami and we realise that those mangroves that were

cut down had a value; they provided a service in terms

of coastal protection. "

 

Similar picture

 

Land-use (habitat) changes, climate change, pollution

and over-exploitation - they are all pushing down on

biodiversity and the pressure shows little sign of

easing.

 

" The magnitude of the challenge of slowing the rate of

biodiversity loss is demonstrated by the fact that

most of the direct drivers of biodiversity loss are

projected to either remain constant or increase in the

near future, " the MA biodiversity synthesis report

says.

 

If you do things the right way, if you chose the

right options for poverty alleviation, you can also

maximise biodiversity and sustainability

 

Dr Georgina Mace, Institute of Zoology

Removing huge swathes of forest has a blunt and clear

impact on biodiversity by taking out the habitat

formerly occupied by plants and animals. But there are

subtle changes taking place, too.

 

The distribution of species around the globe is

becoming more homogenous, as invasive creatures hitch

a ride on fast human transport and trade routes.

 

Genetic diversity, also, is declining rapidly.

 

This is most obvious in domesticated plants and

animals where the pursuit of high yields and the

pressures of global markets have pushed farmers

towards a limited range of cultivars and breeds.

 

And so it is not simply that species are fewer in

number, their changed circumstances may also have

reduced their resilience and their ability to cope

with future change.

 

Possible tensions

 

In 2002, world governments, through the Convention on

Biological Diversity, set themselves the target of

making a " substantial reduction in the rate of loss of

biological diversity " by 2010.

 

The MA illustrates just how tough it will be to meet

that target. What is more, there may even be occasions

when progress towards that target conflicts with the

even loftier 2015 Millennium Development Goals of

cutting into world hunger and poverty, and improving

healthcare.

 

BIODIVERSITY AND POVERTY

Biodiversity and human well-being are inextricably

linked

Humans benefit from ecosystem services, but

unsustainable use drives biodiversity loss

People living in rural areas in developing nations are

often most dependent on biodiversity

And they are usually most vulnerable to ecosystem

service degradation

They cannot afford to move out or import new services

A classic example is the development of rural road

networks - a common feature of hunger reduction

strategies - which are likely also to accelerate rates

of biodiversity loss by fragmenting habitats and by

opening up new areas to unsustainable harvests.

 

This sort of thing has been well documented in Africa

where the bushmeat trade that endangers many species

follows the development of transport infrastructure.

 

" This is a very important issue, " said Dr Mace. " It's

clear there are going to have to be trade-offs and

compromises but it's not a simple relationship. It's

not a case that you can have 20% poverty and 80%

biodiversity.

 

" If you do things the right way, if you chose the

right options for poverty alleviation, you can also

maximise biodiversity and sustainability. "

 

And Dr Neville Ash, another MA synthesis team member,

added: " The bottom line is that you cannot achieve

long-term poverty alleviation without sustainability.

 

" In order to reduce hunger and poverty and increase

access to clean water and sanitation, we need to have

a strong base of environmental sustainability which is

providing these services on which people rely for

their well-being. "

 

Little time

 

It is very evident, too, that we need to get a move

on.

 

The wheels of global governance turn slowly, as was

seen with the Kyoto Protocol on climate change which

finally entered into force in February after many

years of negotiation.

 

The MA has identified possible solutions - from

significant shifts in consumption patterns and better

education, to the adoption of new technologies and a

large increase in the areas enjoying protection.

 

And if some of the ideas sound " old hat " , such as the

abolition of farming subsidies that drive crop

production to the detriment of field biodiversity -

that is because they are.

 

" Most of the approaches to achieving more sympathetic

management of the natural environment and the

conservation of biodiversity - I think we and

governments know them already, " commented Graham

Wynne, the chief executive of the UK bird conservation

group, the RSPB.

 

" The real challenge is to deploy them more extensively

and more intelligently.

 

" And you can't get away from the fact that we simply

need more money.

 

" The sums of money we throw at the environment in the

West are relatively modest; and the sums of money the

West is prepared to devote to developing countries is

pitiful. "

 

 

 

 

 

 

 

 

 

 

 

 

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