Global Warming Debate: Refuting Common Arguments

[Bored Wombat]

It would be nice if examples can be given in the Wegman report to demonstrate that the sciencific conclusion is not supported by rigid unbiased reproduceable science especially when the NAS committee agreed with that conclusion as I showed in my previous post.

No the NA report found the same methodological flaws.

They, however, found that the conclusions were largely sound. Partly because the flaws did not affect the shape of the reconstruction, but only lead to an understating of the errors. And partly because those conclusions were supported by later work.

 

[Bored Wombat]

Edit:
The Wegman report in this link happens to be hosted on a policy maker's website.
Wegman is a scientific report, non-peer reviewed unless one counts the publicly documented statements on Wegman by the authors of the National Academies North report. On the other hand, the Nature News report post https://www.physicsforums.com/showpost.php?p=2419819&postcount=58" up thread on the subject is not peer reviewed material either.

The news at nature is not controversial.

It noted that the NA report found that there were methodological errors, but that these were not material, and it criticised the way the report was used.

But the claims from outside the scientific field were that the whole shape of the hockey stick was due to incorrect methodology, and this was shown not to be the case.

The Wegman report didn't focus so much on the fact that the methodological problems didn't make any material difference, and spent several pages looking at who in the field has published papers with each other ... Which I think is difficult to justify in the absence of any analysis as to what difference this makes to scientific publishing nor the peer review process.

Claiming that Mann et al is in a state of "disfavour" is controversial, because its findings have been nearly completely vindicated. So you need to provide a peer reviewed source to back that up. The Wegman report doesn't establish that "disfavour", certainly not amongst the scientific community. (About whom I assume we are talking about. Certainly there is disfavour from the aforementioned Jo Nova dot com, and other semi-professional science deniers.)

Does the IPCC 2007 report, which reproduces Mann et al 1999 twice, mention anything about its results being questionable?

 

[Bored Wombat]

Of course science marches on and these past reports and reconstructions did not have the following available:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

From the above perspective, it appears that the MWP (950 to 1100) was only minor warming period superimposed on a 1900 year cooling trend that was distinctly interrupted around 1900.

Yes. Global warming is exaggerated at the poles, because CO2 overlaps with H2O, and there's not much atmospheric H2O concentration at the poles.

This gives more evidence that the warming is a greenhouse warming, but it is a little unfair to compare it with temperature reconstructions for the whole hemisphere, because it is stronger than the warming for the whole hemisphere.

 

[Xnn]

Yes. Global warming is exaggerated at the poles, because CO2 overlaps with H2O, and there's not much atmospheric H2O concentration at the poles.

This gives more evidence that the warming is a greenhouse warming, but it is a little unfair to compare it with temperature reconstructions for the whole hemisphere, because it is stronger than the warming for the whole hemisphere.

I agree. However, the reconstructions and analysis that have been done in the past did not have this new source of information available. It's not dependant on tree rings or Michael Mann. So, if a reconstruction of NH temperature history were to be constructed today, it should include this new data, which shows the MWP in an entirely different perspective.

For example, the period 950 to 1100 was not the warmest period prior to 1900 within the Arctic and we can say that the 1990's appear to be the warmest decade for the Arctic over the last 2000.

 

[mheslep]

The news at nature is not controversial.

Yes, it can be as it's news, but that matters not. It is not an peered reviewed source.

It noted that the NA report found that there were methodological errors, but that these were not material, and it criticised the way the report was used.

The mistakes were as I detailed https://www.physicsforums.com/showpost.php?p=2426834&postcount=81", which state that Mann deserves little "confidence" beyond 400 years (their word, not mine). I'd appreciate it if we stick to direct quotes from the sources (Mann and NA), and not other summaries.

But the claims from outside the scientific field were that the whole shape of the hockey stick was due to incorrect methodology, and this was shown not to be the case.

Not interested in claims from non scientific sources for discussion here, hopefully we can dispense with reference to those as well.

Claiming that Mann et al is in a state of "disfavour" is controversial,

Disfavour was a poor word choice on my part, as it smacks of a reliance on some community somewhere. I corrected it above.

because its findings have been nearly completely vindicated.

There's no room for 'completely' in that sentence regarding Mann 99, given the actual source material presented in this thread.

...So you need to provide a peer reviewed source to back that up. The Wegman report doesn't establish that "disfavour", certainly not amongst the scientific community.

As has been discussed in this forum, it's not useful to try and speak for the sentiment of the scientific community. Argument based on the sources is the way to go.

 

[mheslep]

But MBH 1999 is not an outlier amongst reconstructions, and certainly the current view is nearer the MBH view than the pre-MBH view. So I don't think that it has fallen into any "disfavour".

We mean here Mann et al 1999, the millennial reconstruction covering the MWP and featured in the Summary For Policy Makers 2001, not MBH 98's 400 year reconstruction. And yes I think Mann et al 1999 deserves little "confidence" further back than 400 years as the NA report states, and yes I think there's a significant difference between what Mann et al shows around 1000AD, basically showing no MWP to my eye, and what is said in the IPCC 2007

mean temperatures during medieval times (950–1100) were indeed warm in a 2-kyr context

Based on this, other reconstructions shown in IPCC 2007, and my glance at http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg" , I qualitatively call Mann 1999 wrong about the MWP.

 

[mheslep]

Of course science marches on and these past reports and reconstructions did not have the following available:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

From the above perspective, it appears that the MWP (950 to 1100) was only minor warming period superimposed on a 1900 year cooling trend that was distinctly interrupted around 1900.

The actual paper and abstract:

• Kaufman, D.S. et al, 2009. Recent Warming Reverses Long-Term Arctic Cooling, Science 4 September 2009, Vol. 325. no. 5945, pp. 1236 - 1239. DOI: 10.1126/science.1173983

Abstract:

The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000.

http://www.sciencemag.org/cgi/content/abstract/325/5945/1236

I wonder what type of proxies are available at those latitudes. Reading to come.

 

[Bored Wombat]

I agree. However, the reconstructions and analysis that have been done in the past did not have this new source of information available. It's not dependant on tree rings or Michael Mann. So, if a reconstruction of NH temperature history were to be constructed today, it should include this new data, which shows the MWP in an entirely different perspective.

For example, the period 950 to 1100 was not the warmest period prior to 1900 within the Arctic and we can say that the 1990's appear to be the warmest decade for the Arctic over the last 2000.

Good point.

 

[Bored Wombat]

Yes, it can be as it's news, but that matters not. It is not an peered reviewed source.

I’m not saying that news can’t be controversial; I’m saying that in this particular case isn’t controversial.

The NA report was a vindication of Mann et al. The only people saying otherwise are not only not peer reviewed, they’re on website’s whose editorial position is explicitly counterscientific.

The mistakes were as I detailed https://www.physicsforums.com/showpost.php?p=2426834&postcount=81", which state that Mann deserves little "confidence" beyond 400 years (their word, not mine). I'd appreciate it if we stick to direct quotes from the sources (Mann and NA), and not other summaries.

They do not state that Mann deserves little confidence.

They state that less confidence can be placed in the statement that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” than the statement that “the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium.”

The previous paragraph talks more specifically about Mann et al: “The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes the additional large-scale surface temperature reconstructions and documentation of the spatial coherence of recent warming described above (Cook et al. 2004, Moberg et al. 2005b, Rutherford et al. 2005, D’Arrigo et al. 2006, Osborn and Briffa 2006, Wahl and Ammann in press) and also the pronounced changes in a variety of local proxy indicators described in previous chapters (e.g., Thompson et al. in press).”

As I have pointed out already, the error bars in Mann et al 1999 also show that there is not strong confidence in the conclusion that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium”. So again the NA report, is in full agreement with Mann et al on that point.

This is why those secondary sources are all explaining that the NA report backed the hockey stick graph. Now they are not peer reviewed, but neither is your own opinion that they said “that Mann deserves little "confidence" beyond 400 years”. You're misreading the report to get that, you're taking the paragraph about "confidence" isolated, out of context, and claiming it refers to Mann et al (1999) in general. In this case respected secondary sources such as news at nature can be useful, because they make it clear that your analysis is an outlier.

 

[Bored Wombat]

http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg" , I qualitatively call Mann 1999 wrong about the MWP.

It agrees within the error with other reconstructions.

So it's right.

 

[mheslep]

Ah, finally a new page! Guys let's shrink those image posts that explode the page width?

Okay, here's the entire tail end of the http://dels.nas.edu/dels/rpt_briefs/Surface_Temps_final.pdf" without omission. I think it is helpful to post here.

[...]
o Very little confidence can be assigned to statements concerning the hemispheric mean or global mean surface temperature prior to about A.D. 900 because of sparse data coverage and because the uncertainties associated with proxy data and the methods used to analyze and combine them are larger than during more recent time periods.

The main reason that our confidence in large-scale surface temperature reconstructions
is lower before A.D. 1600 and especially before A.D. 900 is the relative scarcity of precisely
dated proxy evidence. Other factors limiting our confidence in surface temperature reconstructions include the relatively short length of the instrumental record (which is used to calibrate and validate the reconstructions); the fact that all proxies are influenced by a variety of climate variables; the possibility that the relationship between proxy data and local surface temperatures may have varied over time; the lack of agreement as to which methods are most appropriate for calibrating and validating large-scale reconstructions
and for selecting the proxy data to include; and the difficulties associated with constructing
a global or hemispheric mean temperature estimate using data from a limited number of sites and with varying chronological precision. All of these considerations introduce uncertainties that are difficult to quantify.

Despite these limitations, the committee finds that efforts to reconstruct temperature histories for broad geographic regions using multiproxy methods are an important contribution to climate research and that these large-scale surface temperature reconstructions contain meaningful climatic signals. The individual proxy series used to create these reconstructions generally exhibit strong correlations with local environmental conditions, and in most cases there is a physical, chemical, or physiological reason why the proxy reflects local temperature variations. Our confidence in the results of these reconstructions becomes stronger when multiple independent lines of evidence point to the same general result, as in the case of the Little Ice Age cooling and the 20th century warming.

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on icecaps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.

Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales.

In addition to this text, the NA report includes Figure S-1 showing other well known reconstructions in which at least two, Moberg et al and Esper et al, are showing circa 1000AD was the warmest part of their proxy reconstructions in the last 1000 years (though they may end in 1980?)

Then note the last part I bold faced. The 'less confidence' in that sentence from the NA does not refer to the wide error bars Mann et al associated with its prior to 1600AD estimates, but rather it refers to the high time resolution claims made in Mann et al's use of the terms 'decade' and 'year', i.e., because not all of the proxies record "information on such short timescales." Specifically on this point of making claims re short timescales, NA is not in agreement with Mann et al.

NA also prefers the word "plausible" over "likely" about the warmest period in a 1000 years. As an amateur, I agree.

 

[Bored Wombat]

In addition to this text, the NA report includes Figure S-1 showing other well known reconstructions in which at least two, Moberg et al and Esper et al, are showing circa 1000AD was the warmest part of their proxy reconstructions in the last 1000 years (though they may end in 1980?)

But less than the temperatures in the 1990s.

Then note the last part I bold faced. The 'less confidence' in that sentence from the NA does not refer to the wide error bars Mann et al associated with its prior to 1600AD estimates,

That's right.
Mann et al's error analysis is independently in agreement with the NA report on this.

but rather it refers to the high time resolution claims made in Mann et al's use of the terms 'decade' and 'year', i.e., because not all of the proxies record "information on such short timescales." Specifically on this point of making claims re short timescales, NA is not in agreement with Mann et al.

Largely it is. Mann et al says nearly exactly the same thing materially.

NA also prefers the word "plausible" over "likely" about the warmest period in a 1000 years. As an amateur, I agree.

No, they don't compare "plausible" to any other term. But if that's the basis of your claim that Mann et al. "deserves little confidence", that Mann et al used the word "likely" whereas the NA used the word "plausible", then you make too much of the language and not enough of the error analysis in Mann et al.

 

[Andre]

"The future problem these animals face is via displacement by alien species from lower latitudes. Such invasions are now well documented from sub-Antarctic sites." - http://www.frontiersinzoology.com/content/2/1/9" , Peck, Frontiers in Zoology 2005, 2:9 doi:10.1186/1742-9994-2-9

Perhaps for example: "Warming is likely to remove
physiological barriers on lithodid crabs that currently place a
limit on the invasion of shallow waters of the high Antarctic;
a scenario that is especially likely for waters oV the Antarctic
Peninsula" - http://epic.awi.de/Publications/Tha2008c.pdf"
Thatje et al, Polar Biol (2008) 31:1143–1148 DOI 10.1007/s00300-008-0457-5

(http://www.independent.co.uk/enviro...life-threatened-by-crab-invasion-782989.html", as the popular press put it)

http://www.telegraph.co.uk/science/science-news/3325543/Antarctic-seabed-ecosystems-invasion-threat.html" is another popular press write up, this time about a presentation at the AAAS conference in 2008:
"Unique Antarctic seabed ecosystems are under threat from invasions of species taking advantage of global warming, scientists have warned.

Predatory giant crabs, sharks and other fish are poised to make a return to the rapidly warming shallow waters around the South Pole for the first time in tens of millions of years.

Their come-back will disrupt the make-up of ancient communities of unusual animals such as sea spiders, brightly-coloured brittle stars, thin-shelled muscles and giant relatives of the woodlouse called isopods."

But, again, this is hardly controversial. The fact that species range changes is contributing to the 30% biodiversity drop over the past few decades is well marked in ecology.

and the times, they are a changing:

http://www.sciencemag.org/cgi/content/summary/326/5954/806

Over the past decade, several models have been developed to predict the impact of climate change on biodiversity. Results from these models have suggested some alarming consequences of climate change for biodiversity, predicting, for example, that in the next century many plants and animals will go extinct (1) and there could be a large-scale dieback of tropical rainforests (2). However, caution may be required in interpreting results from these models, not least because their coarse spatial scales fail to capture topography or "microclimatic buffering" and they often do not consider the full acclimation capacity of plants and animals (3). Several recent studies indicate that taking these factors into consideration can seriously alter the model predictions (4–7).

 

[mheslep]

and the times, they are a changing:

Interesting what happens at higher resolution. More from Willis and Bhagwat:

[...]
In one study, Randin et al. assessed the influence of spatial scale on the accuracy of bioclimatic model predictions of habitat losses for alpine plant species in the Swiss Alps (4). A coarse European-scale model (with 16 km by 16 km grid cells) predicted a loss of all suitable habitats during the 21st century, whereas a model run using local-scale data (25 m by 25 m grid cells) predicted persistence of suitable habitats for up to 100% of plant species.
[...]
Many studies have indicated that increased atmospheric CO2 affects photosynthesis rates and enhances net primary productivity—more so in tropical than in temperate regions—yet previous climate-vegetation simulations did not take this into account.

 

[Bored Wombat]

Interesting what happens at higher resolution. More from Willis and Bhagwat:

That is interesting.

And it helps explain why the "Extinction Risk" paper poorly modeled extinction over the end of the last glaciation.

But an isolated community with a small gene-pool is still on the road to extinction. It can be wiped out by a small land use change, or flood or fire, and has little capacity to adapt to change or disease.

So, while it improves modelling I don't think that it genuinely affects the observed facts such as: "The fact that species range changes is contributing to the 30% biodiversity drop over the past few decades is well marked in ecology."

 

[Bored Wombat]

and the times, they are a changing:

This is a modelling exercise, and probably a fine one in that it explains why there was so few (although nevertheless notable) extinctions at the end of the last glaciation.

However, the invasion of subantarctic systems by temperate predators is being observed, and the documentation of these events is prolific.

Times are indeed changing, because the climate is indeed changing, and the devastation of that is mostly undocumented, but not so in the subantarctic.

But it seems like you are suggesting that the implication is that your paper refutes this observed devastation. It does not.

 

[mheslep]

...So, while it improves modelling I don't think that it genuinely affects the observed facts such as: "The fact that species range changes is contributing to the 30% biodiversity drop over the past few decades is well marked in ecology."

Eh? I don't think you mean to quote your https://www.physicsforums.com/showpost.php?p=2419819&postcount=58" paper you provided. It makes no statement about 'observing' a 30% drop. Rather Thomas estimates, as do Willis and Bhagwat.

 

[Bored Wombat]

Eh? I don't think you mean to quote your https://www.physicsforums.com/showpost.php?p=2419819&postcount=58" as a reference for the facts ?

Sure I did.

That was the statement that I made that I thought that you were taking issue with.

I don't think that your argument is an argument against that position.

Also, where is your reference for "observed" in that context?

Observed drop in biodiversity or Observed range changes?

For the latter I posted a few in this post, but my point is that it is not controversial, and the reason I chose that paper is because is mentions that point: "Such invasions are now well documented from sub-Antarctic sites."

The observed drop in biodiversity is from the http://assets.panda.org/downloads/living_planet_report_2008.pdf" .

The only topical biodiversity reference I can find in the thread (aside from Andre's Willis and Bhagwat reference) is the http://www.gbltrends.com/doc/nature02121.pdf" paper you provided. It makes no statement about 'observing' a 30% drop. Rather Thomas estimates, as do Willis and Bhagwat.

The living planet index of biodiversity, as in the report linked above.

 

[mheslep]

Bored Wombat - above you made the statement that the following is "an observed fact"

[...]The fact that species range changes is contributing to the 30% biodiversity drop over the past few decades is well marked in ecology.

I contend that statement as shown is unsupportable and requires substantial qualification to become valid. The Living Planet Report is a popular reference compiled in part by activists (WWF), which is fine though you didn't initially cite it as such, but the 30% drop shown there refers to an index of 1,686 vertebrate species, on a planet with http://www.guardian.co.uk/environment/2009/sep/29/number-of-living-species" . We have not 'observed' a 30% drop in the biodiversity of this planet. We have observed, if we accept this popular source, a 30% drop in a limited collection of vertebrates over several decades. Also, from this popular source it is only fair to say that such a decrease is commonly recognized by activist groups; the science of ecology speaks through published scientific literature.

 

[Bored Wombat]

Bored Wombat - above you made the statement that the following is "an observed fact"
I contend that statement as shown is unsupportable and requires substantial qualification to become valid.

I contend that I have supported it with the well known and well cited living planet report.

The methods of the report appear in the scientific literature, such as:
http://rstb.royalsocietypublishing.org/content/360/1454/289.full" , (doi: 10.1098/rstb.2004.1584 Phil. Trans. R. Soc. B 28 February 2005 vol. 360 no. 1454 289-295)

And it is cited and used as a source of data for scholarly papers that appear in the scientific literature:
http://www3.interscience.wiley.com/cgi-bin/fulltext/121521774/HTMLSTART", (Conservation Biology, Volume 23, Number 2, April 2009 , pp. 317-327(11)

The Living Planet Report is a popular reference compiled in part by activists (WWF), which is fine though you didn't initially cite it as such, ...

It is research funded in part by an NGO, and published as one report by an NGO. Lots of research is funded by NGOs.

... but the 30% drop shown there refers to an index of 1,686 vertebrate species, on a planet with http://www.guardian.co.uk/environment/2009/sep/29/number-of-living-species" .

I know that this is a physics and not a statistics board, but my understanding is that the size of the population (the 11 million) doesn't affect the accuracy of the estimate derived from a sample. What matters is the sample size (the 1,686), and any selection bias in the sampling.

We have not 'observed' a 30% drop in the biodiversity of this planet. We have observed, if we accept this popular source, a 30% drop in a limited collection of vertebrates over several decades.

30% over the 35 years to 2005. "Several decades" sounds like more than that.

Also, from this popular source it is only fair to say that such a decrease is commonly recognized by activist groups; the science of ecology speaks through published scientific literature.

And the living planet index appears in the published scientific literature, as per the examples above.

If you think that the scientific literature has a better accepted estimate of biodiversity, I will certainly read your citation, so please provide one.

 

[mheslep]

I contend that I have supported it with the well known and well cited living planet report.

The methods of the report appear in the scientific literature, such as:
http://rstb.royalsocietypublishing.org/content/360/1454/289.full" , (doi: 10.1098/rstb.2004.1584 Phil. Trans. R. Soc. B 28 February 2005 vol. 360 no. 1454 289-295)

And it is cited and used as a source of data for scholarly papers that appear in the scientific literature:
http://www3.interscience.wiley.com/cgi-bin/fulltext/121521774/HTMLSTART", (Conservation Biology, Volume 23, Number 2, April 2009 , pp. 317-327(11)

Now you have, with appropriate cites, thanks.

I know that this is a physics and not a statistics board, but my understanding is that the size of the population (the 11 million) doesn't affect the accuracy of the estimate derived from a sample. What matters is the sample size (the 1,686), and any selection bias in the sampling.

That's roughly correct, though the problem here is 1) the sample admits to being non-random on its face (only vertebrates), 2) it would be nearly impossible to make a non-biased sample for a global population which is mostly unknown. But this is all beside the point. The point here is that your statement about global biodiversity can only be an estimate, as you admit above (my highlight), only the sample is observed.

 

[Nebula815]

Isn't it impossible to really know how many species are dying on the planet? Scientists don't know how many species there are to begin with, furthermore (at least from my understanding) species die all the time and new ones are created all the time.

Also, how does one figure out exactly if a species has died? I mean you can try to count the species in a certain area, then come back again later on and count them again, but maybe some have moved to a different location...? For big animals, like whales, or gorillas or woolly mammoths, I can see it being easy to see if they're extinct, but things like insects, plants, etc...seems awfully tricky.

 

[Evo]

We are discovering tons of new species all of the time.

Over 350 new species including the world's smallest deer, a "flying frog" and a 100 million-year old gecko have been discovered in the Eastern Himalayas, a biological treasure trove now threatened by climate change.

The region studied covers a vast expanse of the mountain region.

A decade of research carried out by scientists for the WWF in remote mountain areas brought discoveries such as a bright green frog that uses its red and long webbed feet to glide in the air.

The WWF report, "The Eastern Himalayas -- Where Worlds Collide," details discoveries made by scientists from various organizations between 1998 and 2008 in a region reaching across Bhutan and northeast India to the far north of Myanmar as well as Nepal and southern parts of Tibet in China.

"The good news of this explosion in species discoveries is tempered by the increasing threats to the Himalayas' cultural and biological diversity," Jon Miceler, Director of WWF's Eastern Himalayas Program, said in a press statement.

http://www.cnn.com/2009/TECH/science/08/11/eco.himalayas.newspecies/index.html#cnnSTCText

A frog that eats birds and a gecko with leopard stripes are among the 163 new species discovered last year in the Greater Mekong region of southeast Asia, according to a report by the World Wildlife Fund.

The discovery of 100 new plants, 28 fish, 18 reptiles, 14 amphibians, two mammals and one bird species highlights the extent of the biodiversity in the region, said Barney Long, head of the WWF's Asian Species Conservation program.

"It's a melting pot of diverse habitats. It has some of the wettest forests on the planet, high mountains, and a diverse array of terrestrial and marine habitats, including the Mekong River," he said.

"We continue to find new species of fish, primates and mammals, and nowhere else compares to the amount of large mammals that have been discovered in the region. It shows how little we know about species in the region," he said. "From a biodiversity perspective, there are still huge amounts to discover about region."

http://www.cnn.com/2009/TECH/science/09/26/mekong.species/index.html#cnnSTCText

A rat believed to be extinct for 11 million years, a spider with a foot-long legspan, and a hot pink cyanide-producing "dragon millipede" are among the thousand newly discovered species in the largely unexplored Mekong Delta region.

The "dragon millipede" is among the 1,068 new species discovered in the Mekong Delta region.

The region, including parts of Vietnam and five other countries, is home to 1,068 species found between 1997 and 2007, according to a World Wildlife Fund report released this week.

http://www.cnn.com/2008/TECH/science/12/16/rat.mekong/index.html#cnnSTCText

The list goes on and on.

 

[Bored Wombat]

Now you have, with appropriate cites, thanks.

Okay.

I still think that the report itself is a respected enough piece of science, and not just those facets of it which produced scholarly papers.

That's roughly correct, though the problem here is 1) the sample admits to being non-random on its face (only vertebrates),

It's not random. But its not necessarily strongly biased.

Would invertebrates be more or less affected than vertebrates?

2) it would be nearly impossible to make a non-biased sample for a global population which is mostly unknown.

That's true if you wanted any population of any species to have an equal chance of being selected, but the living planet index makes it's estimate by tracking members of ecosystems that are assumed to be representative of those ecosystems.

It's probably not too bad.

But this is all beside the point. The point here is that your statement about global biodiversity can only be an estimate, as you admit above (my highlight), only the sample is observed.

Every measurement is an estimate.

A study is not faulty for using a sample, and for the 1 significant figure that I quoted (30%), that sample is sufficient.

 

[Bored Wombat]

Isn't it impossible to really know how many species are dying on the planet? Scientists don't know how many species there are to begin with, furthermore (at least from my understanding) species die all the time and new ones are created all the time.

Species do die all the time, but currently they are dying at some orders of magnitude faster than the long term average.

Most biologists say that we are in a geologically significant mass extinction.

There's not any scientific evidence for the view that new ones are created. There is certainly some evidence that new ones evolve. The rate is difficult to estimate, and speciation events depends more on the separation of populations so that they don't interbreed than with new ecological niche.

Rattus Rattus will be one species the world over, until they stop boarding cargo ships, although their behaviour and form might become more varied to allow exploitation of new food sources as human technology changes.

But speciation also depends on genetic diversity. (As does the existence of a species itself in many ways). So the population drops from land use change, pollution, over exploitation and climate change will also lower the speciation rate.

Natural speciation occurs in the long term trend only a few times per year or once every few years ... give or take an order of magnitude.

Currently extinctions are occurring approximately hourly ... give or take an order of magnitude.

So there's an imbalance.

The downside is about threefold:

Firstly, and most scientifically, humans require the biosphere for air and food. And so does everything else. There will be keystone species upon which groups of species depend on, which include species that we depend on. Because we don't know what they are, we need to maintain biodiversity.

Secondly, and least scientifically, animals are cute, and living on the world is a lesser thing for our grandchildren if they only live in a world without tigers, polar bears or coral reefs.

Thirdly and most interestingly, biodiversity is an academic resource. Each plant or animal has it's unique proteins that may be of some great medical or biotechnological value. Each one you lose is hundreds or thousands of these chemicals that are lost to science. Since this resource cannot be replaced, is should not be depleted without the greatest need.

Also, how does one figure out exactly if a species has died? I mean you can try to count the species in a certain area, then come back again later on and count them again, but maybe some have moved to a different location...?

It's not always easy, and you can get some pleasant surprises, especially with plants - whose seeds may lie dormant for years or decades.

It doesn't really matter in terms of policy which ones are the ones that are extinct though. Dropping biodiversity is a Bad Thing™, and we should try to stop it.

 

[Bored Wombat]

We are discovering tons of new species all of the time.

Yes.

The loss of species that are undiscovered is not a smaller loss though. If anything, it is a greater loss, because it gives science a much less opportunity to have learned from it.

And the description and naming of a species, while certainly a noble thing, is not an increase in biodiversity.

 

[Evo]

Yes.

The loss of species that are undiscovered is not a smaller loss though. If anything, it is a greater loss, because it gives science a much less opportunity to have learned from it.

And the description and naming of a species, while certainly a noble thing, is not an increase in biodiversity.

There is no question that humans are destroying natural habitats at an alrming rate through agriculture, ranching, construction, destroying wetlands, destroying forests, killing off species that other species need to live on. But this is direct physical harm by man.

 

[mheslep]

...A study is not faulty for using a sample,

I've not contradicted the academic papers on the LPI in this thread, I'm not qualified to do so absent other contradictory sources. The Loh et al 2005 (Phil Trans B.) authors report their data; they go to some length to point out limitations such as over representation of some types of species (http://rstb.royalsocietypublishing.org/content/360/1454/289/F7.large.jpg" .

I'm faulting the '30% biodiversity drop' and 'observation' parts of your statement in #105, for which you attempt to use the LPI to show that these are widely accepted conclusions, but which if you read the reference actually contradict your statement there about biodiversity:

The LPI indicates that populations of wild species of vertebrates have declined overall from 1970 to 2000. The extent to which this is a reflection of trends in global biodiversity as a whole has not been determined.
[...]
There are also a number of weaknesses with the LPI as a global biodiversity index. These weaknesses all relate to the representativeness of the population data.

I contend a fair summary of these papers can go little further than to say something like "The Living Planet Index, a weighted index of vertebrate population data, has shown a ~30% decline from 1970 to 2000" without distorting the paper.

 

[mheslep]

There is no question that humans are destroying natural habitats at an alrming rate through agriculture, ranching, construction, destroying wetlands, destroying forests, killing off species that other species need to live on. But this is direct physical harm by man.

Right, and especially given the study referenced in this thread indicating that climate influences on species loss are overblown, it seems to me we'd get far more for our money in terms of preserving species by, e.g., buying up large areas of rain forest in Brazil and protecting them, rather than rushing out to paper over the all coal plants with solar panels in 5-10 years and forswearing air travel.

 

[Nebula815]

How can biologists think we are in a mass extinction if we don't know how many species there are on the Earth in the first place though? As said, we are discovering new ones all the time. Is there a documented list of thousands of species dying off every ten years or so...?

There is no question that humans are destroying natural habitats at an alrming rate through agriculture, ranching, construction, destroying wetlands, destroying forests, killing off species that other species need to live on. But this is direct physical harm by man.

Some of this I would say is the result of a lack of economic development in certain countries though. For example, I believe we have more trees per capita in the United States today than we did 150 years ago, because of modern farming techniques, which allow us to grow far more food utilizing far less land. This has allowed many areas that used to be farmland to grow back into forest.

Or in Third World countries, a lot of unnecessary destruction of plants and rainforest occurs because the people need the trees for energy (burn the wood).

That said, economic development if unchecked (lack of proper regulations and rules) will certainly destroy nature too (a big coal plant without proper exhaust filtration and a chemical plant dumping waste into a river are certainly highly destructive!).

One should also remember that different species mess things up for other species too, for example trees could technically be viewed as a big weed, one that sprouted up and cut off the sunlight and sucked all the water out of the ground, making it impossible for smaller plants to survive.

What we call "nature" is in many ways a constant battle of different species battling for dominance and survival. Nature is not a happy balance that humans came along and messed up.