2010-10-04 06:14:46Basic rebuttal no. 96: The IPCC were wrong about the Amazon Rainforests
Rob Painting


An article in a British newspaper claimed that the Intergovernmental Panel on Climate Change (IPCC) published wrong information about the Amazon Rainforest in their 2007 report. The issue centred on the statement that about 40% of the Amazon was susceptible to the effects of drought, or more specifically "slight reductions in rainfall".

The Amazon is the world's largest tropical rainforest, and due to its immense size, has a global effect on the Earth's climate. Despite being well adapted and resilient to wet and dry periods which occur throughout the year, the rainforest is vulnerable to extended periods of drought. Any major decline in the health of the Amazon rainforest is likely to impact the world climate.

The skeptic claims relate to section 13.4.1 of the IPCC Fourth Assessment Report (2007) which made the statement: 'Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation' (Rowell and Moore, 2000)

The reference is to a non-peer reviewed report prepared by the World Wide Fund for Nature (WWF) which itself cites an original peer reviewed study (Nepstad 1999) as the basis for the claim. The citations in the WWF and IPCC reports are not complete, Nepstad 1994, Nepstad 1999 and Nepstad 2004 support the claim that up to half the Amazon rainforest were severely affected by drought. Further studies, carried out since the 2007 IPCC report, reinforce the Amazon's susceptibilty to long term reductions in rainfall .

The IPCC could have avoided confusion by simply citing the peer reviewed studies themselves, rather than the WWF report and perhaps "slight reduction" should have been better defined or qualified. Despite the error in citation, the statement made by the IPCC is factually correct. Maybe the last word should go to the lead author of the papers upon which the statements were based, Daniel Nepstad, who made a public press release to clear up the mainstream media confusion over the subject. Nepstad concludes:

"In sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement."

2010-10-04 06:23:02



My usual complaint about the reading level still applies.

Think about the barmaid.

2010-10-04 06:32:22well done
Dana Nuccitelli

A few minor comments.

"well adapted" -> well-adapted

"El Nino" -> El Niño

"Despite the error in citation [comma]"

Personally I'm a fan of linking to the referenced  studies, even in the basic version.

Overall it may be a bit long for the basic version, but I like it.  Good explanations and not too complicated.

2010-10-04 06:49:18


This covers all the important stuff. It's a sacred cow so we can expect intense criticism. 

Some quibbles etc.:

"On the back of an article published in a British newspaper..." Does that mean "buried in" or the like? Seems a little awkward.

"it's" --> "its" in a few places, a mistake I make when typing fast... 

"The Amazon is the world's largest tropical rainforest covering some 6.7 million square kilometers, and aside from it's considerable ecological value, the region is significant from a global climate perspective for a number of reasons, but perhaps the two most important being, firstly, that it currently acts as a carbon sink, meaning it is absorbing more carbon dioxide from the atmosphere, than it emits." Putting on my Neal hat, that seems a pretty challenging sentence for the average reader.  

Might emphasize, the words in the press release are Nepstad's own.  


2010-10-04 08:00:04


Nothing to add.

The sentence quoted by Doug can be easily splitted. If you want to make the post shorter, you may omit it,. Same thing for the third paragraph. Though, both are well written and informative.

2010-10-04 17:56:18
Rob Painting
Cheers, points duly noted. I'll have another crack at it.  
2010-10-16 22:46:01
Rob Painting
Bump. 2nd attempt.   
2010-10-17 03:27:45


"...Daniel Nepstad, whom made a..." ---> "...Daniel Nepstad, who made a..."

Unfortunately it's plain fact that "World Wildlife Federation" drops a red veil over the vision of exactly the same crowd driven mad by global warming. If IPCC had cited a grey paper from the American Enterprise Institute there would have been no problem here.

So this won't satisfy skeptics but is a reasonable explanation. All the same, is it worth possibly a -few- words on what a grey paper is, that is to say they may be written by scholars or other experts, with a scholarly approach informed by expertise, but not peer-reviewed? Probably not worth it...


2010-10-17 10:01:57
Rob Painting

Doug, I could write "the IPCC was wrong about the Amazon" to satisfy the skeptics, but then it wouldn't be true. There is nothing we can say that a contrarian won't whine about.  

I did consider explaining the difference with peer review & grey literature, or maybe linking to an explanation, but sometimes these things have a tendency to distract from the essential points. I'll perhaps link to something if others consider it worthwhile. 

I've got the nuts and bolts of the advanced version sorted out, (I didn't realize there was so much literature on the topic) and will try to get that finished soon. 




2010-10-17 10:51:36

I think it's ok now.
2010-10-17 23:08:23


"10-4," Dappledwater; the rebuttal's good to go. 

On a general note, at some point maybe it would be helpful to do an article on what "grey literature" really is. It's a lousy term, for starters; "grey literature" suggests failed laundry or what goes down the sink after washing up, when in reality we're talking about factual utilitarian reports for the most part.

2010-10-17 23:35:36WWF = World Wide Fund For Nature


Globally, the meaning of the abbreviation "WWF" was updated from "World Wildlife Fund" to "World Wide Fund For Nature" in 1986, just not in the US and Canada.

This is from WWF's A&Q-page:

What do the initials WWF stand for?

  • WWF originally stood for "World Wildlife Fund".
  • However, in 1986, WWF had come to realize that its name no longer reflected the scope of its activities, and changed its name to "World Wide Fund For Nature".
  • The United States and Canada, however, retained the old name.
  • The resulting confusion caused by the name change in 1986, together with its translation into more than 15 languages, led the WWF Network in 2001 to agree on using the original acronym as its one, global name - the acronym that it had always been known by since its inception way back in 1961: WWF
  • Find out more on the panda symbol and how it has changed over the years...

Not sure what is the best name to use on a globally read website...


2010-10-18 06:47:40
Rob Painting
Baerbel, World Wide Fund for Nature is the term used here in NZ too. I've changed it as you've suggested.
2010-10-20 05:44:51
Bruce Worden

Looks good.

"The citations are not complete" => "The citations in the WWF report are not complete"

You could add a footnote to WWF explaining that it is known as the World Wildlife Fund in the U.S. and Canada, but I don't think it's a big issue.


2010-10-20 07:00:47
Rob Painting
Amended as suggested.
2010-10-25 07:19:25Comment
Robert Way

I like it.
2010-10-26 15:43:16
Andy S


Yes, this is very good. This ought to be clear enough to a non-technical reader and I don't think that it could be safely simplified any more. 

I would imagine that anyone stumbling across this for the first time would want to know which newspaper(s) broke it, why they pushed the story, how the IPCC responded and the fact that the Sunday Times eventually retracted it. I know, this veers into politics, an area this blog correctly opts to steer clear of, but that's the essence of this sorry tale, unfortunately. But perhaps that belongs in the advanced version.

2010-10-30 00:32:41Published
John Cook


Added this. Thanks Rob (and nice clean HTML, good stuff!)

Can I just say I love the headline? Graham Wayne would be proud of that one.