Before you read this, I’ll remind WUWT readers of this essay:
Where Are The Corpses? Posted on January 4, 2010 by Willis Eschenbach
Which is an excellent primer for understanding the species extinction issue. Willis pointed out that there are a lot of holes in the data collection methods, and that has proven itself this week when this furry little guy (below) announced himself to a couple of volunteer naturalists at a nature reserve in Colombia two weeks ago and was identified as the thought to be extinct red-crested tree rat. It hasn’t been seen in 113 years. Oops.
IPCC report based on “fundamentally flawed” methods that exaggerate the threat of extinction – The pace at which humans are driving animal and plant species toward extinction through habitat destruction is at least twice as slow as previously thought, according to a study released Wednesday.
Earth’s biodiversity continues to dwindle due to deforestation, climate change, over-exploitation and chemical runoff into rivers and oceans, said the study, published in Nature.
“The evidence is in — humans really are causing extreme extinction rates,” said co-author Stephen Hubbell, a professor of ecology and evolutionary biology at the University of California at Los Angeles.
But key measures of species loss in the 2005 UN Millennium Ecosystem Assessment and the 2007 Intergovernmental Panel on Climate Change (IPCC) report are based on “fundamentally flawed” methods that exaggerate the threat of extinction, the researchers said.
The International Union for the Conservation of Nature (IUCN) “Red List” of endangered species — likewise a benchmark for policy makers — is now also subject to review, they said.
“Based on a mathematical proof and empirical data, we show that previous estimates should be divided roughly by 2.5,” Hubbell told journalists by phone.
“This is welcome news in that we have bought a little time for saving species. But it is unwelcome news because we have to redo a whole lot of research that was done incorrectly.”
Up to now, scientists have asserted that species are currently dying out at 100 to 1,000 times the so-called “background rate,” the average pace of extinctions over the history of life on Earth.
UN reports have predicted these rates will accelerate tenfold in the coming centuries.
The new study challenges these estimates. “The method has got to be revised. It is not right,” said Hubbell.
How did science get it wrong for so long?
Because it is difficult to directly measure extinction rates, scientists used an indirect approach called a “species-area relationship.”
This method starts with the number of species found in a given area and then estimates how that number grows as the area expands.
To figure out how many species will remain when the amount of land decreases due to habitat loss, researchers simply reversed the calculations.
But the study, co-authored by Fangliang He of Sun Yat-sen University in Guangzhou, shows that the area required to remove the entire population is always larger — usually much larger — than the area needed to make contact with a species for the first time.
“You can’t just turn it around to calculate how many species should be left when the area is reduced,” said Hubbell.
That, however, is precisely what scientists have done for nearly three decades, giving rise to a glaring discrepancy between what models predicted and what was observed on the ground or in the sea.
Dire forecasts in the early 1980s said that as many as half of species on Earth would disappear by 2000. “Obviously that didn’t happen,” Hubbell said.
But rather than question the methods, scientists developed a concept called “extinction debt” to explain the gap.
Species in decline, according to this logic, are doomed to disappear even if it takes decades or longer for the last individuals to die out.
But extinction debt, it turns out, almost certainly does not exist.
“It is kind of shocking” that no one spotted the error earlier, said Hubbell. “What this shows is that many scientists can be led away from the right answer by thinking about the problem in the wrong way.”
Human encroachment is the main driver of species extinction. Only 20 percent of forests are still in a wild state, and nearly 40 percent of the planet’s ice-free land is now given over to agriculture.
Some three-quarters of all species are thought to live in rain forests, which are disappearing at the rate of about half-a-percent per year.
Species–area relationships always overestimate extinction rates from habitat loss
Nature473,368–371(19 May 2011)
Extinction from habitat loss is the signature conservation problem of the twenty-first century1. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions. The most widely used indirect method is to estimate extinction rates by reversing the species–area accumulation curve, extrapolating backwards to smaller areas to calculate expected species loss. Estimates of extinction rates based on this method are almost always much higher than those actually observed2, 3, 4, 5. This discrepancy gave rise to the concept of an ‘extinction debt’, referring to species ‘committed to extinction’ owing to habitat loss and reduced population size but not yet extinct during a non-equilibrium period6, 7. Here we show that the extinction debt as currently defined is largely a sampling artefact due to an unrecognized difference between the underlying sampling problems when constructing a species–area relationship (SAR) and when extrapolating species extinction from habitat loss. The key mathematical result is that the area required to remove the last individual of a species (extinction) is larger, almost always much larger, than the sample area needed to encounter the first individual of a species, irrespective of species distribution and spatial scale. We illustrate these results with data from a global network of large, mapped forest plots and ranges of passerine bird species in the continental USA; and we show that overestimation can be greater than 160%. Although we conclude that extinctions caused by habitat loss require greater loss of habitat than previously thought, our results must not lead to complacency about extinction due to habitat loss, which is a real and growing threat.
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So . . . . rather than just counting the total number of known species and then identifying which no longer exist, estimating extinction date based on last known sighting and extrapolating from that . . .
They chose to look at the number of species in a given area of land, determine the rate of increase in the number of species as that area increases, reverse the process and estimate extinction based on habitat destruction.
And NOBODY saw the flaw in that logic? ? ?
[REPLY] Well, yes. I saw the flaw in the logic. w.
Uhm, excuse me while I puke. Genuine Science no longer exists outside of physics and chemistry. Bio-, Climate, Enviro, Social . . . are no longer real science. This post normal crap has to end. Once people no longer believe in real science (and we are getting there because of this kind of B.S.) it’s going to be tough to win them back. They’ll refuse to fund real science because of all the fake science.
Al Gored,
It looks like that it was spotted again,
Ivory-Billed Woodpecker Sighted and Recorded
http://www.sciencedaily.com/releases/2011/04/110428132236.htm
“Only 20 percent of forests are still in a wild state, and nearly 40 percent of the planet’s ice-free land is now given over to agriculture.”
I call BS!
There is no way 40% of the planet’s land is involved in agriculture. Any fool with Google earth can quickly ascertain that fact.
90% of the earth’s land is unsuitable for agriculture. I’ve seen a good bit of this world up close and personal; parts that have tremendous agricultural potential, and parts that have zero. Let me tell you; the parts that have zero outweigh the other by at least 4 or 5 to one. Even the parts that are highly productive you don’t get more than about 40 or 50 percent of the land actually tilled and planted. Mind you quite a bit of the remainder is used up for roads, farm buildings, fence rows, etc. and is therefore no longer in it’s natural state, but to the claim that 40% of the earth’s land is “now given over to agriculture” is just blatant stupidity.
Yes, and up next I suppose they’ll say that the missing extinction events are trapped in the oceans.
After all, it’s a pretty direct parallel, they use models based on surface temps while the majority of the Earth’s surface, not to mention thermal content, is the oceans. I’ve no doubt that the majority of living organisms are aquatic as well, and our knowledge of these is orders of magnitude poorer than our knowledge of land-based organisms, which as previously mentioned is not all that great.
Natural selection, survival of the fittest are well accepted concepts. That means that humans will necessarily have an impact on other species. However, whenever we do things that diminish one species we are improving conditions for the species that are food for the diminished species. In addition, we now create situations for new species to evolve.
One can argue whether the “new balance” of species is good or bad, but to claim that we are changing the laws of nature is pure nonsense.
This should be obvious to anyone trained in natural systems. So, why do we constantly see the species extinction BS? Just a another version of CAGW? Yup, another scare to keep the lemmings in line and the research fund flowing.
Except when you pause to consider how many squirrels, rabbits, snakes, frogs, lizards, racooons, and opossums you find in your back yard in the MIDDLE of a city. It seems that many species – perhaps most – are a lot more adaptable than some faux scientists.
Where Are The Corpses?
Probably buried at sea !!
One reasonable view of global biological capacity would be that it is energy dependent. The more energy, the more biological capacity our planet provides. If this is true then AGW would be a good thing for *life* itself (up to a certain maximum the Earth has never experienced).
In addition, we could think of renewable energy sources like wind/solar/wave/etc. to be sapping energy from the system which would have a negative impact on biological capacity. Fossil fuels, OTOH, take sequestered energy and add it to the total. A net gain for overall biological capacity.
P.G. Sharrow says:
May 19, 2011 at 9:36 pm
“Human encroachment is the main driver of species extinction. Only 20 percent of forests are still in a wild state, and nearly 40 percent of the planet’s ice-free land is now given over to agriculture.”
40% given over to agriculture?? Can’t even get that fact correct, not even close. pg
I am sure you are right. looks to me like the 40% of the non-icecovered land given up to agriculture is mistatement of actual data.
I always thought it was 40% of arable land ( ie. land fit and available for agriculture ).
so, figured i will go check. this is what i found.
in the following site, you can see a number close to 40% as being used for agriculture. the first thing that will jump at you is Saudi arabia… According to Saudi Govt, less than 2% of the land is used for agriculture. but this website says 86.8% of agri usage. I guess they mean 86.8% of the land that they can cultivate… which is about 2%.
http://www.nationmaster.com/graph/agr_agr_lan_of_lan_are-agriculture-agricultural-land-of-area
I believe that the Earth’s biodiversity declined with the extinction of the dinosaurs too.
What that caused by “global warming” and by mankind?
Alan the Brit: that is the coelacanth.
http://en.wikipedia.org/wiki/Coelacanth
Re; nandheeswaran jothi @ur momisugly
May 20, 2011 at 9:12 am
” . . . . that will jump at you is Saudi arabia… According to Saudi Govt, less than 2% of the land is used for agriculture. but this website says 86.8% of agri usage. I guess they mean 86.8% of the land that they can cultivate… which is about 2%.”
Funny, I went through almost the exact same exercise, but with the U.S. instead. Result; 2,426,936,000 total acres of ground in the 50 United States. Used to produce crops last year; 318,170,000. Per the National Agricultural Statistics Service, part of the Department of Agriculture. That’s roughly 13% of total land area. If you figure 25% fallow (probably a very high estimate) you get to about 17% in crop production. From what I can see; any ground that is grazed (or even licensed for grazing) is automatically counted as agricultural. In some states, like Wyoming, that is the majority of the agricultural use land. Most of it is largely ungrazed.
When you consider that the difference between pastureland and native prairie is largely whether there’s any type of livestock either standing on it, or allowed to stand on it, I fail to see how that ground is unsuitable in any way for native species.
I think the scientists are making the assumption that any ground ‘given over to agriculture’ is plowed under and farmed. It’s just not so.
Anyway; that’s in the U.S.. The most productive agricultural nation on earth, siting on the most productive continent on earth, using the most advanced technology and resources available.
So . . . in conclusion; to state that 40% of the worlds land not covered in ice is used for agricultural production is outside of reality. Just not possible. Human beings do not occupy 40% of the earth’s land in any meaningful way. It takes a scientist living in a big city surrounded by buildings, streets and people to not understand that.
LOL!
I announced to my boss that they have been calculating the extinction rate wrong (they are REALLY in to biodiversity here).
She asked “Is it worse than we thought?”
I told her it was better.
She replied “Then that can’t possibly be right.”
The paper is a sham: it does not report extinction rates or the numbers of species that are threatened. Despite its posturing, it deals with a different issue. The paper is riddled with false statements. For instance:
The paper states: “Estimates of extinction rates based on (the species-area) method are almost always much higher than those actually observed.” It is unequivocally false. One reference used to support this (Pimm and Askins) uses a species-area relationship to predict 4.5 bird extinctions following deforestation in Eastern North America and then notices that four species went extinct and one is threatened.
There are dozens of other studies of many taxa around the world that find equally compelling agreements between predicted and observed extinctions. A small selection of them follows.
So what does the paper model — and why does it poorly address the issue of extinctions? Imagine destruction that wipes out 95% of the habitat in an area metaphorically “overnight”. How many species have disappeared “the following morning”? The paper tells you. It is not many, just those wholly restricted to the 95% (and absent from the 5% where they would survive). The important question is …
How many of additional species living lonely lives in their isolated patches (the 5%) would become extinct eventually because their population sizes are too small to be viable? A different species-area curve applies — the one for islands, which are isolated. It is a much larger number of extinctions, of course, and the one used in the studies mentioned above that find such compelling agreement between predicted against observed extinctions.
By all means, feel free to share this.
A response will be submitted to Nature shortly.
Stuart
Pimm, S. L. & Askins, R. A. Forest losses predict bird extinctions in eastern North America. Proc. Natl Acad. Sci. USA 92, 9343–9347 (1995).
Brooks, T. M. et al. Habitat loss and extinction in the hotspots of biodiversity. Conserv. Biol. 16, 909–923 (2002).
Grelle, C. E. de V., Fonseca, G. A. B., Fonseca, M. T. & Costa, L. P. The question of scale in threat analysis: a case study with Brazilian mammals. Animal Conserv. 2, 149–152 (1999).
Brooks, T. & Balmford, A. Atlantic forest extinctions. Nature 380, 115 (1996).
Cowlishaw, G. Predicting the pattern of decline of African primate diversity: an extinction debt from historical deforestation. Conserv. Biol. 13, 1183–1193 (1999).
Brook, B. W., Sodhi, N. S. & Ng, P. K. L. Catastrophic extinctions follow deforestation in Singapore. Nature 424, 420–423 (2001)
Brooks, T. M., S. L. Pimm, V. Kapos and C. Ravilious 1999. Threat from deforestation to montane and lowland birds and mammals in insular Southeast Asia. J. Anim. Ecol. 68: 1061-1078
Brooks, T. M., Pimm, S. L., & Oyugi, J. O. Time lag between deforestation
and bird extinction in tropical forest fragments. Conserv. Biol. 13, 1140-1150
(1999).
A full discussion of species area curves appears in
Rosenzweig, M.L. Species diversity in space and time. (Cambridge Univ.
Press, 1995)
Every WUWT reader will find a very interesting discussion of the hypothised “current sixth mass extinction” in Patrick Moore’s book “Confessions of a Greenpeace dropout – the making of a sensible environmentalist”.
Really worth reading on many, many issues such as chemicals, forestry, energy, population by a man who knows Greenpeace better than many outsiders ! After being really one of those who “made” Greenpeace”, he has the experience of coping with their extremist, black and white, claims.
This is just more epidemiological junk-science, and Hubbell’s insistence that it is based on empirical evidence is BS. The worse part is that this crap gets published.
PhilJourdan says…..
Some species do adapt well to urbanisation, foxes in the UK for example are too successful. I would guess that other species wouldnt be, gorillas for example.
BS! – Endangered Species
http://www.megavideo.com/?v=8I288OH6
As I’ve mentioned before, one way to protect a lot of species is to provide propane grills and fuel in places like Central America, so the locals can stop cutting down the rain forests for cooking fuel. Also a certain amount of modern fertilizers and machinery could help improve the yields of lands that are already clear and reduce the temptation to clear rain forests lands for crops. These sorts of ideas don’t tend to appeal to the more romantic sort of environmental activist, of course.
oh that was informative..keep updatin us 🙂
Poptech says:
May 20, 2011 at 7:14 am
Al Gored,
It looks like that it was spotted again,
Ivory-Billed Woodpecker Sighted and Recorded
http://www.sciencedaily.com/releases/2011/04/110428132236.htm
————
I don’t buy it. Not just the flimsy evidence. Too many birders looking for too long, with too small of an area for those birds to hide in, for them to ‘hide’ for so long.
There would need to be a breeding population to survive that long. Where are the juvenile dispersers looking for new territories? They would have ventured out of any secret core hiding spot with population growth – and there would have been population growth under this scenario. But none reported for all those years? The whole story is biologically and ecologically nonsensical. Always has been.
And look where it was published: Journal of the Acoustical Society of America.
This fellow may be suffering from a bad case of wishful thinking. And if anyone is trying to create some new park or wilderness area they would help him wish this.
There are lots of very ‘odd’ events like this. Like the miraculous reappearance of the ‘American Jaguar.’ But at least they had real jaguars to work with.
stuart pimm says:
May 20, 2011 at 10:48 am
“The paper is a sham…
One reference used to support this (Pimm and Askins) uses a species-area relationship to predict 4.5 bird extinctions following deforestation in Eastern North America and then notices that four species went extinct and one is threatened.”
Yes. Well. That’s four extinct species out of the grand total of SEVEN that have gone extinct in the recorded history of North America. And one, the ‘Heath Hen’ was arguably a subspecies.
Or has it skyrocketed to EIGHT? Not sure if they have finally decided that the Eskimo Curlew is gone. It probably is. Its population was decimated back when there was a real extinction crisis in North America.
See Willis’s great article – at the top – for a nice summary of that.
First, my thanks to all those who have commented.
I first began work on what eventually became my blog post on extinctions in 2004 … so when the the authors of the article ask:
I have to say, “Well, not all scientists got it wrong. I didn’t.”
Next, Mike says:
May 20, 2011 at 6:38 am
“Using 40 percent of all the ‘plant biomass'”??? Get real, that number doesn’t pass the laugh test, much less the smell test. It’s a bogus claim originally put forward by Paul Ehrlich in his risible “HUMAN APPROPRIATION OF THE PRODUCTS OF PHOTOSYNTHESIS” by Peter Vitousek, Paul R. Ehrlich, Anne H. Ehrlich and Pamela Matson (1986)
In it, they claim that human “appropriation” of the green growing stuff
of the planet, depending on exactly what “appropriation” means at a given moment,
ranges from their low estimate of 3% to their high estimate of 40%.
Now to me, that reflects a poorly defined term … but they get around
that by giving the Goldilocks estimate, three separate numbers.
At the 3% level, “appropriation” means what you would expect it
to mean — what we actually eat and wear and use to build our houses
with, the stuff we actually use.
At the 40% level, however, “appropriation” means what we eat and
wear and build with, plus:
• everything that grows in any human owned pastures and
fields, regardless of whether a human ever touches it, plus
• the annual difference in production between what we grow
on a piece of land versus their theoretical calculation of what could
have grown on the same land, plus
• the annual production that might have happened where we
put our roads and cities (figured, of course, at the highest possible
production rates), plus
• the apples that fall off your tree and are eaten by the
birds, or rot in the soil, plus
• (I kid you not) calculated annual production lost through
“desertification”, whatever they choose for that to mean on a given
day.
So when you see a deer grazing in your back yard, he’s not really
eating that grass, you are, because it’s happening in your yard, and by
the Ehrlich’s calculation that makes it a human “appropriation” of the
products of photosynthesis.
w.
Bob Kutz says:
May 20, 2011 at 7:31 am
And a good call it is. The best source on this is the UN FAO Global Agro-Ecological Zone Study (GAEZ). Here’s their numbers:
<code.Land Surface Coverage
Forest, 21.2%
Desert and Barren, 20.9%
Woodland, 14.5%
Grassland, 13.6%
Mosaics, 8.5%
Cropland, 8.3%
Ice, Cold Desert, 5.9%
Lakes, rivers, 3.3%
Irrigated, 3%
Wetland, 0.7%
Urban, 0.2%
w.