Elke twee jaar brengt het WWF een update uit van de Living Planet Index (LPI), het rapportcijfer voor de natuur op aarde. Dit rapportcijfer is in 2020 weer een stuk gedaald ten opzichte van 2018, maakte het WWF deze week bekend. Spoiler: dit zegt niets over hoeveel diersoorten zijn uitgestorven, en vrijwel niets over hoeveel wilde dieren er nog op aarde zijn.
De Living Planet Index (LPI) is een soort Dow Jones index van de natuur: één cijfer dat pretendeert aan te geven hoe het momenteel met de natuur op aarde gesteld is. De LPI gaat uit van de situatie in 1970, die per definitie de score 100 heeft. Elke twee jaar inventariseert het World Wild Life Fund (WWF, met als Nederlandse tak het Wereldnatuurfonds) zoveel mogelijk betrouwbare tellingen van populaties wilde dieren. Insecten en ander klein grut wordt niet meegenomen in de LPI; het gaat om zoogdieren, vogels, vissen, reptielen en amfibieën.
Hoewel er veel geteld wordt door biologen en ecologen over de hele wereld, worden bij lange na niet alle tienduizenden diersoorten, laat staan de miljoenen afzonderlijke populaties wilde dieren, periodiek geteld. Ook is de kleine minderheid van soorten en populaties waarvoor betrouwbare tellingen over een lange tijdsperiode bestaan, op geen enkele manier een representatieve steekproef van alle diersoorten. Niettemin wordt elke telling uitgedrukt in een percentage met 1970 als referentie, en via een meertrapsproces van wegen en middelen in het eindcijfer opgenomen.
Tweederde minder?
De LPI is sinds 1970 gestadig gedaald, en was in 2018 met 60 procent afgenomen. De update voor 2020 geeft een daling aan van 68 procent, dus een verdere daling met 8 procentpunten. In dit tempo zal de LPI rond 2050 onder de 1 procent zakken.
Het is nog even afwachten hoe de LPI 2020 in de nieuwsmedia gaat resoneren, maar de verwarring die de LPI 2018 veroorzaakte was bijna komisch: de één maakte er van dat 60 procent van de diersoorten sinds 1970 is uitgestorven, de ander dat 60 procent van de dierenpopulaties is verdwenen, en weer een ander dat 60 procent van alle wilde dieren is verdwenen. ‘Hoe bedoel je, dat is niet hetzelfde? Nou ja, zoiets, het is in ieder geval heel erg’, zullen ze op die redacties wel gedacht hebben.
Toegegeven, het is ook verwarrend. Daarom staat in het LPI 2020 rapport op pagina 17 expliciet vermeld:
What the LPI does not tell us
– The LPI doesn’t show numbers of species lost or extinctions.
– It does not mean that X% of species or populations are declining.
– Or that X% of populations or individuals have been lost.
Vertaling (met 68% ingevuld voor X):
Wat de LPI ons niet vertelt
– De LPI laat geen aantallen verdwenen soorten of uitstervingen zien
– Het betekent niet dat 68% van de soorten of populaties in aantal afneemt
– Of dat 68% van de populaties of individuen verdwenen is
Op de eigen website omschrijft het Wereldnatuurfonds dit zo:
‘Dit jaar laat het rapport zien dat wereldwijd de omvang van populaties zoogdieren, vissen, vogels, reptielen en amfibieën gemiddeld is afgenomen met 68% sinds 1970.’
Maar als populaties gemiddeld met 68 procent zijn afgenomen, hoe kan het dan, dat niet ook ongeveer 68 procent van de dieren is verdwenen?
Om dat echt te snappen moet je niet bij het lijvige rapport zelf zijn, maar bij het technical supplement. Terwijl het technical supplement bij de LPI 2018 subtiel in de luwte werd gehouden, is het technical supplement bij de LPI 2020 online gewoon onvindbaar, hoewel het rapport zelf er herhaaldelijk naar verwijst. Ik ga er daarom maar van uit, dat het systeem om de LPI te berekenen sinds 2018 niet wezenlijk veranderd is.
Het ene gemiddelde is het andere niet
Als je dat helemaal uitpluist, blijkt de schijnbaar onschuldige term ‘gemiddeld’ beladen met een rekensystematiek die vol arbitraire keuzes zit. Zo maakt het voor zijn invloed op de LPI niets uit hoe groot een populatie is. Fictief voorbeeld: de afname met 50 procent van een piepkleine populatie visjes in, zeg, één bergmeertje in de Andes, weegt in deze systematiek even zwaar als een toename met 30 procent van de Noord-Atlantische zalm. Dat komt neer op maar een paar Andes-visjes minder en miljoenen zalmen erbij, maar de LPI voor deze twee populaties gezamenlijk is dan -35 procent.
De rekenmethode is zelfs zodanig (het geometrisch gemiddelde nemen, voor de fijnproevers) dat de LPI over willekeurig veel populaties dieren die allemaal een gezonde groei vertonen, door één populatie die percentueel sterk afneemt, omlaag kan worden getrokken tot een afname.
Daar bovenop komt dan nog een systeem van weegfactoren per groep dieren die de uiteindelijke LPI nog ondoorzichtiger maakt. En tenslotte zit er waarschijnlijk een forse selectie bias in welke soorten vooral door biologen geteld worden, namelijk de zeldzame, bedreigde soorten.
Misschien zijn er wel méér dieren
Ondanks de alsmaar dalende LPI, is het best mogelijk dat er nu meer wilde dieren op aarde zijn dan in 1970. Immers, de aarde is al sinds 1970 aan het vergroenen, in de zin dat de natuur jaarlijks netto miljarden tonnen koolstof in de vorm van CO2 uit de lucht opneemt. Dat wordt allemaal omgezet in biomassa, dus bomen, struiken, vruchten, zeewier en dergelijke. Al dat extra groen is in principe voer voor planteneters, die weer voer voor vleeseters zijn. En als er ergens extra aanbod van voedsel is, grijpt de natuur altijd haar kans.
Dat die kansen er wel degelijk nog zijn, blijkt ook uit een ander gegeven in het LPI-rapport: van alle getelde soorten is de helft ofwel in aantal toegenomen, of ongeveer even groot gebleven. Er is dus geen sprake van dat de natuur planeetbreed aan het afsterven is. Er zijn ecosystemen waarmee het heel slecht gaat, ecosystemen waarmee het heel goed gaat, en allerlei ecosystemen daar tussenin. Dat maakt het weergeven van de staat van de mondiale natuur in een soort Dow Jones-index tot een onzinnige exercitie, hoe creatief de boekhouder ook is die je daar op los laat.
Het Living Planet Report 2020 (Nederlandse samenvatting, en volledig rapport in het Engels). https://www.wwf.nl/wat-we-doen/focus/biodiversiteit/living-planet-report/2020
Mijn gedetailleerde ontleding van de Living Planet Index en andere indicatoren voor de gezondheid van de natuur, oorspronkelijk gepubliceerd in tijdschrift Skepter. http://www.exponentry.eu/focusatscience/articles/Biodiversiteit.pdf
Gepubliceerd op Wynia’s Week
Geschreven door: Arnout Jaspers
Gepubliceerd op: 12 september 2020
102 thoughts on “Opinie: De natuur is niét planeetbreed aan het afsterven”
I am not sure where you are getting your info, but great topic.
I needs to spend some time learning more or understanding more.
Thanks for fantastic info I was looking for this information for my mission.
Thanks designed for sharing such a nice opinion, piece of writing is
pleasant, thats why i have read it entirely
I simplу cߋuld not leave your websitｅ bеfore suɡgesting that I extrеmely enjοyed the standard info aan individսal shpply
oon your guests? Is going toߋ Ьe back continuously in ᧐rder to investigatre cross-check new posts
my site – cmd368
Simply desire to say your article is as surprising.
The clarity on your publish is just great and that i can think you’re knowledgeable in this subject.
Fine together with your permission allow me to snatch your RSS feed
to keep up to date with coming near near post. Thank you one million and
please carry on the rewarding work.
Check out my web page True Burn Keto Cost
Thanks for sharing your info. I really appreciate your efforts and I will be waiting for your next
post thank you once again.
Woah! I’m really enjoying the template/theme of this blog.
It’s simple, yet effective. A lot of times it’s tough to get that “perfect balance” between usability and visual appearance.
I must say that you’ve done a excellent job with this.
In addition, the blog loads super fast for me on Opera.
Exceptional Blog!
This is the perfect blog for anybody who hopes to find out about this topic.
You know a whole lot its almost tough to argue with you (not that I really would
want to…HaHa). You definitely put a fresh spin on a subject which
has been written about for years. Great stuff, just excellent!
WOW just what I was searching for. Came here by searching for website
Thank you for sharing with us, I think this website genuinely stands out :
D.
Feel free to visit my web-site: Ketorol Reviews
Hi! I could have sworn I’ve been to this website before but
after looking at many of the posts I realized it’s new
to me. Anyhow, I’m definitely pleased I came across it and I’ll be bookmarking it and checking back often!
I’ve been exploring for a little for any high quality articles or
blog posts on this kind of area . Exploring in Yahoo I finally stumbled upon this website.
Studying this info So i am satisfied to show that I’ve a very good uncanny feeling I found
out exactly what I needed. I such a lot certainly will make
sure to do not forget this web site and give it a look on a continuing basis.
Also visit my site: Pure Keto Burn Review
Since the admin of this web site is working,
no question very quickly it will be renowned, due
to its feature contents.
Can I simpⅼy ssay what a relief to discover ѕomеbody that actually knows what they’re talking about online.
You certainly realize how to bring ann issսe to light and make it important.
A ⅼot more pｅolle ought to read this аnd understand this side of the story.
I was surprised that you aren’t more popular bеcause you cеrtainly possesѕ the gift.
My site :: taruhanbol
Tһanks a lot for sharing thuis with alll people
youu really knoᴡ ᴡhat you are speaking aƄout!
Bookmarked. Kindly аdditionally talk oveｒ with my site =).
We cϲan have a link exсhange agrеement among us
my web blog :: Baca Disini
Everyone loves what you guys tend to be up too.
This kind of clever work and reporting! Keep up the awesome
works guys I’ve included you guys to my blogroll.
Have you ever considered creating an e-book or guest authoring on other websites?
I have a blog centered on the same subjects you discuss and would love
to have you share some stories/information. I
know my audience would appreciate your work. If you are
even remotely interested, feel free to send me
an e mail.
Also visit my web-site Optimum Keto Reviews
Ahaa, its pleasant dialogue concerning this article here at this weblog, I have read
all that, so now me also commenting at this place.
Hi there, You have done an excellent job.
I’ll certainly digg it and in my opinion recommend to my friends.
I am confident they’ll be benefited from this
web site.
Also visit my webpage :: Arctos Portable Air Conditioner
Ꮋі mates, nice piecе oof writing aand nice urging commented at
this place, I am truly enjoying by these.
Check out my ѡeb blog … taruhanbol
If you are going for finest contents like I do, simply visit this web page everyday because it
gives feature contents, thanks
Also visit my webpage :: Optimum Keto Review
Hellօ, I rea your blog dailʏ. Yоuur writing stｙle is awesome, keｅp it up!
My web blog; situs judi live casino indonesia
If you are going for finest contents like myself, only pay a quick visit this
web site every day as it provides feature contents, thanks
If some one wishes to be updated with latest technologies afterward he must
be pay a visit this web site and be up to date daily.
We stumbled over here from a different web page and
thought I may as well check things out. I like what I
see so i am just following you. Look forward to looking into your web page again.
Review my page – Pure Keto Burn
Normally I don’t learn post on blogs, however I wish
to say that this write-up very compelled me to take a look at and
do it! Your writing style has been amazed me. Thanks, very nice article.
Hey! This is my first visit to your blog! We are a team of volunteers and starting a new initiative in a community in the
same niche. Your blog provided us valuable information to work on. You have done
a marvellous job!
Hi there, I enjoy reading through your article post.
I wanted to write a little comment to support you.
An intriguing discussion is definitely worth comment.
I think that you ought to publish more about this topic, it might not be a taboo matter but typically people don’t talk about
such topics. To the next! Many thanks!!
Fantastic site. A lot of helpful info here. I am sending it to some friends ans also sharing
in delicious. And obviously, thanks in your effort!
Since the admin of this web page is working, no doubt
very rapidly it will be famous, due to its quality contents.
my web-site: Vigor Max Male Enhancement
Now I am ready to do my breakfast, when having my breakfast coming yet
again to read other news.
Keep on writing, great job!
Also visit my web-site: Niva CBD
I know this web site offers quality based articles and extra information, is there
any other website which provides these kinds of stuff in quality?
No matter if some one searches for his necessary thing, therefore
he/she wishes to be available that in detail, therefore that
thing is maintained over here.
Good respond in return of this matter with solid arguments and
describing everything concerning that.
Thanks for sharing your info. I really appreciate your efforts and I will
be waiting for your next post thank you once again.
Nice post. I learn something totally new and challenging on blogs I stumbleupon everyday.
It’s always interesting to read content from other authors and practice a little something from other web sites.
I am extremely impressed with your writing skills as well
as with the layout on your blog. Is this a paid theme or did you customize it yourself?
Either way keep up the excellent quality writing, it’s rare to see
a great blog like this one these days.
I blog quite often and I really appreciate your information. This article has
really peaked my interest. I will book mark your website and keep checking
for new details about once per week. I subscribed to your RSS feed as
well.
Thank you for your blog post. Thomas and I have already been saving for just a new publication on this theme and
your post has made us to save all of our money.
Your thinking really answered all our concerns. In fact, more than what we had known in advance of the time we came upon your amazing blog.
We no longer nurture doubts plus a troubled mind because you have really attended
to each of our needs in this post. Thanks
Feel free to surf to my page Luiresse Cream
I like this blog very much so much wonderful information.
Stop by my site – Infinuity CBD Gummies; librarius.main.jp,
Wow that was strange. I just wrote an very long comment
but after I clicked submit my comment didn’t show up. Grrrr…
well I’m not writing all that over again. Anyways, just wanted to say great
blog!
Remarkable! Its actually awesome article, I have got much clear idea regarding from this paragraph.
My relatives all the time say that I am wasting my time here at web,
but I know I am getting experience everyday by reading such pleasant content.
I would like to thank you for the efforts you’ve put in writing this blog.
I am hoping the same high-grade website post from you
in the upcoming as well. In fact your creative
writing abilities has encouraged me to get my own web site
now. Really the blogging is spreading its wings fast.
Your write up is a great example of it.
my blog: Viking XL Keto Reviews; http://www.hltkd.tw,
Right here is the right webpage for everyone who really
wants to understand this topic. You understand a whole lot its almost
hard to argue with you (not that I personally will need to…HaHa).
You definitely put a brand new spin on a subject that’s been discussed for decades.
Great stuff, just wonderful!
What i don’t understood is in reality how you are no longer
really much more smartly-appreciated than you may be now.
You are so intelligent. You already know thus considerably in the case of this topic, produced me in my view consider it from
a lot of numerous angles. Its like women and men aren’t
fascinated until it is one thing to do with Lady
gaga! Your personal stuffs nice. Always maintain it up!
Hey there, You have done an excellent job.
I’ll definitely digg it and personally recommend to
my friends. I’m confident they’ll be benefited from this web
site.
Feel free to visit my web blog :: Ice House Portable AC
You made some decent points there. I looked on the web for additional information about the issue and
found most individuals will go along with your views on this website.
My web page – Bio Shed Keto Slim (https://bbs.cnction.com)
It’s actually a nice and helpful piece of information. I am
satisfied that you shared this useful info with us. Please stay
us up to date like this. Thanks for sharing.
Visit my blog – Wawza Apple Cider Vinegar, http://www.koan.at/UserProfile/tabid/61/userId/185450/Default.aspx,
Pretty nice post. I just stumbled upon your weblog and
wished to say that I’ve really enjoyed surfing around your blog posts.
After all I’ll be subscribing to your feed and
I hope you write again very soon!
Wonderful beat ! I would like to apprentice even as you amend your site, how can i subscribe for a blog web site?
The account helped me a appropriate deal. I had been tiny bit familiar of
this your broadcast offered bright transparent concept.
Here is my website Aizen Power – librarius.main.jp
–
Some genuinely nice stuff on this internet site, I love it.
Feel free to visit my blog – Moscatcher
Hi, for all time i used to check weblog posts here in the early
hours in the dawn, as i like to learn more and more.
Well I sincerely liked studying it. This article procured by you is very practical for good planning.
Look at my blog post; Green CBD Gummies
My partner and I stumbled over here by a different page and thought I may as well check things
out. I like what I see so i am just following you.
Look forward to finding out about your web page for a second time.
Heya i am for the first time here. I came across this board and I
find It truly useful & it helped me out a lot.
I hope to give something back and aid others like you helped me.
Feel free to visit my homepage Viking XL Keto Reviews
Ridiculous story there. What happened after? Good luck!
Thank you for some other informative blog. Where else may I am getting that type of information written in such an ideal way?
I’ve a challenge that I’m just now operating on, and I have been at the
glance out for such information.
Its such as you learn my thoughts! You appear to understand a lot about this, like you wrote the
ebook in it or something. I feel that you could do with a few percent to force the message home a little bit, however instead of that, this is magnificent
blog. A fantastic read. I’ll certainly be back.
Here is my web blog :: Luiresse Cream [https://www.nazisociopaths.org/modules/profile/userinfo.php?uid=220752]
When someone writes an piece of writing he/she retains the
thought of a user in his/her mind that how a
user can be aware of it. Therefore that’s why
this article is great. Thanks!
I like the valuable information you supply in your articles.
I’ll bookmark your weblog and test once more here regularly.
I’m quite sure I’ll be told many new stuff proper right here!
Best of luck for the following!
I simply could not leave your site prior to suggesting that I actually loved the usual info a person provide for your guests?
Is going to be again regularly in order to investigate cross-check new posts
Its such as you learn my thoughts! You appear to grasp so much approximately
this, such as you wrote the e book in it or something.
I believe that you simply can do with some % to pressure the message house
a bit, but instead of that, this is great blog.
A fantastic read. I will definitely be back.
But wanna input that you have a very decent site, I like the design and style it really stands
out.
my webpage – SynoGut
Excellent post. I was checking constantly this blog and I’m impressed!
Very helpful information specifically the last part 🙂 I
care for such information a lot. I was looking for this particular info for a long time.
Thank you and good luck.
I’m extremely pleased to find this website. I need to to thank you for your time for this fantastic read!!
I definitely liked every part of it and I have you saved as a favorite to look at new stuff on your web site.
Here is my homepage: Wawza Apple Cider Vinegar
Unquestionably believe that which you said. Your favorite justification seemed to be on the net the easiest thing to take into account of.
I say to you, I definitely get annoyed while other people consider
issues that they just do not realize about. You controlled to hit the nail upon the highest and defined out
the entire thing with no need side effect , other folks
can take a signal. Will likely be back to get more.
Thank you
I do not even know how I ended up here, but I thought this
post was good. I don’t know who you are but certainly you’re going
to a famous blogger if you aren’t already 😉 Cheers!
Sweet blog! I found it while surfing around on Yahoo News.
Do you have any suggestions on how to get listed in Yahoo News?
I’ve been trying for a while but I never seem to get there!
Appreciate it
Hi there! Do you know if they make any plugins to protect against hackers?
I’m kinda paranoid about losing everything I’ve worked hard on. Any recommendations?
Hi friends, nice piece of writing and nice arguments commented here,
I am genuinely enjoying by these.
Incredible points. Outstanding arguments. Keep up the great spirit.
I’m extremely inspired with your writing skills and also with the format in your
blog. Is that this a paid topic or did you customize it your self?
Either way keep up the nice high quality writing, it’s rare to peer a great weblog like this one nowadays..
What’s up, just wanted to mention, I loved
this post. It was funny. Keep on posting!
Neat blog! Is your theme custom made or did you download it from somewhere?
A theme like yours with a few simple adjustements would really make my blog stand out.
Please let me know where you got your design. Thanks
Enjoyed examining this, very good stuff, appreciate it.
My homepage … TetraMale
Pretty element of content. I simply stumbled upon your web site and in accession capital to
assert that I acquire in fact loved account your blog posts.
Any way I will be subscribing to your feeds and even I achievement you access consistently fast.
Look into my site; The Skin Company (Marylyn)
If you wish for to increase your know-how just keep visiting
this website and be updated with the hottest information posted here.
Aw, this was a very nice post. Spending some time and actual effort to make a top notch article?
but what can I say? I put things off a whole lot and don’t
seem to get anything done.
My webpage; Vialis Male Enhancement Reviews (http://www.koan.at/UserProfile/tabid/61/userId/182133/Default.aspx)
Hola! I’ve been reading your web site for a long time now and finally got the
courage to go ahead and give you a shout out from Porter Texas!
Just wanted to say keep up the fantastic job!
That is a good tip especially to those new
to the blogosphere. Simple but very accurate information… Thanks for sharing this one.
A must read article!
You are so cool! I do not suppose I’ve read anything like this before.
So good to find someone with some original thoughts on this subject
matter. Really.. thank you for starting this up.
This web site is one thing that’s needed on the web, someone with a
little originality!
Hello would you mind sharing which blog platform
you’re working with? I’m going to start my own blog in the near future but I’m having a hard time choosing between BlogEngine/Wordpress/B2evolution and Drupal.
The reason I ask is because your design seems different then most blogs and
I’m looking for something completely unique.
P.S Sorry for getting off-topic but I had to ask!
Excellent blog you have got here.. It’s difficult to find quality writing
like yours nowadays. I seriously appreciate people like you!
Take care!!
I like this blog very much, Its a really nice situation to read and incur info.
Visit my web page: Optimum Keto
I’ve learn several just right stuff here.
Certainly price bookmarking for revisiting. I surprise how much attempt you put to create one of these magnificent informative website.
Hi there! I just wish to give you a huge thumbs up for the excellent info you have got here
on this post. I will be coming back to your blog for more soon.
It’s very effortless to find out any matter on net as compared to books, as
I found this article at this web site.
I couldn’t refrain from commenting. Very well written!
With havin so much content and articles do you ever run into any problems of plagorism or copyright infringement?
My site has a lot of completely unique content I’ve either authored myself or outsourced but it
appears a lot of it is popping it up all over the internet without
my permission. Do you know any methods to help reduce content from being ripped off?
I’d certainly appreciate it.
It’s awesome to pay a visit this web page and reading the views of all mates
on the topic of this article, while I am also eager of
getting experience.
Thank you, I’ve just been looking for information about this
subject for ages and yours is the best I have came upon so far.
But, what concerning the conclusion? Are you positive about the supply?
Thank you for sharing your thoughts. I really appreciate your efforts and I
will be waiting for your next post thanks once again.
It’s very effortless to find out any topic on web as compared to textbooks, as
I found this paragraph at this website.
I was suggested this blog by my cousin. I am not sure whether this post is
written by him as nobody else know such detailed about my
trouble. You are wonderful! Thanks! quest bars http://j.mp/3C2tkMR quest bars
This blog was… how do you say it? Relevant!! Finally I have found
something which helped me. Thanks a lot! asmr https://app.gumroad.com/asmr2021/p/best-asmr-online asmr
Quality articles or reviews is the main to interest
the viewers to pay a quick visit the web site, that’s what this web page is providing.
cheap flights http://1704milesapart.tumblr.com/ cheap
flights
Hmm it appears like your website ate my first comment (it was extremely long) so I guess I’ll
just sum it up what I submitted and say, I’m thoroughly enjoying
your blog. I as well am an aspiring blog writer but I’m still new to everything.
Do you have any tips for beginner blog writers?
I’d genuinely appreciate it. quest bars https://www.iherb.com/search?kw=quest%20bars quest bars
I blog quite often and I truly thank you for your
content. The article has truly peaked my interest.
I am going to book mark your site and keep checking for new details about once a week.
I subscribed to your Feed too. scoliosis surgery
https://0401mm.tumblr.com/ scoliosis surgery
I always emailed this website post page to all my contacts, because
if like to read it afterward my contacts will too.
scoliosis surgery https://coub.com/stories/962966-scoliosis-surgery scoliosis surgery
When someone writes an article he/she maintains the image of a
user in his/her brain that how a user can know it.
Thus that’s why this paragraph is amazing. Thanks! ps4 games https://bitly.com/3z5HwTp ps4 games