Efter klimaforandringerne

Diverse — Drokles on April 26, 2012 at 12:35 pm

Marxzisterne forsvandt ikke med Murens fald, de havde allerede nye fortællinger parat om det multietniske paradis der skulle fremmes fordi det var uundgåeligt. Og klimatisterne forsvinder heller ikke når truslen fra bedre vejr uddør i de næste 2-5 år. Der sadles allerede om nu til den næste store økologiske trussel som kun dine penge kan redde og kun hvis du opgiver dit småborgerlige og egoistiske demokratiske indflydelse. Scientific American

Governments from more than 90 countries have agreed to establish an independent panel of scientists to assess the very latest research on the state of the planet’s fragile ecosystems. The decision, which will create a body akin to the Intergovernmental Panel on Climate Change (IPCC), was made in Panama City this weekend, after years of negotiations.

The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) will be responsible for producing international scientific assessments on issues such as ocean acidification and pollination, to help policy-makers to tackle the global loss of biodiversity and degradation of ecosystems.

“I hope that this body will allow biodiversity to be better taken into account in sustainable-development strategies, as the IPCC has for climate change over the past 20 years,” says Irina Bokova, director-general of the United Nations Educational, Scientific and Cultural Organization (UNESCO), based in Paris.

Og problemerne vil være de samme som i klimadebatten, nemlig at man forud har besluttet af arter forsvinder med katastrofal hastighed, eller som det hedder “We are indeed experiencing the greatest wave of extinction since the disappearance of the dinosaurs.” endnu inden man ved det ringeste om hvor mange arter der er til at starte med. Og derfor indfører man computermodeller, som BBC’s Richard Knight fortæller

It is possible to count the number of species known to be extinct. The International Union for Conservation of Nature (IUCN) does just that. It has listed 801 animal and plant species (mostly animal) known to have gone extinct since 1500.

But if it’s really true that up to 150 species are being lost every day, shouldn’t we expect to be able to name more than 801 extinct species in 512 years?

Professor Georgina Mace, who works in the Centre for Population Biology at Imperial College London, says the IUCN’s method is helpful but inadequate. “It is never going to get us the answers we need,” she says. That’s why scientists prefer to use a mathematical model to estimate species loss.

Recently, however, that model has been attacked in the pages of Nature. Professor Stephen Hubbell from the University of California, Los Angeles, says that an error in the model means that it has - for years - over-estimated the rate of species loss.

The model applies something called the “species to area relationship” to habitat loss. Put simply, an estimate is made of the number of species in a given area, or habitat - the larger the area, the greater the number of species are said to be in it.

Then the model is worked backwards - the smaller the area, the fewer the species. In other words, if you measure habitat loss, you can use the model to calculate how many species are being lost as that habitat gets smaller.

The problem, says Hubbell, is that the model does not work in reverse. “The method,” he says, “when extrapolated backward, doesn’t take into account the fact that you need to remove more area to get to the whole range of a species than you need to remove area to find the first individual of a species.”

Hubbell’s point is that if you increase a habitat by, say, five hectares, and your calculations show that you expect there to be five new species in those five hectares, it is wrong to assume that reversing the model, and shrinking your habitat, eliminates five species.

Biodiversitetstruslen har dog ikke det samme religiøse potentiale som klimavanviddet. Klimateorien knyttede direkte menneskets udånding sammen med Jordens undergang og gik sprogligt skridtet videre ved blot at tale om kulstof, det alt liv er skabt af, som den store synder.  Artsudryddelse er en konkret og begrænset problemstilling og selve menneskets eksistens er ikke under anklage.

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