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Up is Down, Brown is Green (with apologies to Orwell)

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In the alternate universe of Fox News, Anthony Watts, and many others, up is down. Now, it appears, brown is green. Following the total confusion over the retraction of a paper on sea level, claims of another “mistake” by the IPCC are making the rounds of the blogosphere. This time, the issue is the impact of rainfall changes on the Amazon rainforest.

A study in 2007 showed that the forest gets greener when it rains less. A new study, by Samanta et al. in Geophysical Research Letters shows that the earlier work was flawed. Aided by an apparently rather careless press release, this is being used as evidence that the Amazon is less sensitive to rainfall changes than the IPCC claimed. But the Samanta et al. paper actually does not address the central questions at all. It only addresses whether a single anomalous rainfall year had an impact that is measureable and interpretable from a satellite sensor. The conclusion is that they could not detect a change. As noted in a commentary from Simon Lewis, University of Leeds, “the critical question is how these forests respond to repeated droughts, not merely single-year droughts.”

Lewis – a broadly published expert on tropical forests – makes a number of additional important points in his commentary below. Bottom line: IPCC gets it right as usual.

—————
Guest Commentary by Simon Lewis, University of Leeds, UK

The new Samanta et al. study uses sensors on satellites to assess the colour of the rainforest canopy in the dry season of the year 2005, compared to the dry seasons of the years 2003 and 2004. More detected green colour in 2005 may suggest that the forest is being more productive (more green leaves photosynthesising), or more brown colours may suggest leaves dying and less productivity, than the previous years. The results show that 2005 was little different to the previous years, despite the strong drought.

This is important new information, as in 2007, a paper using broadly the same satellite-based method showed a strong ‘greening-up’ of the Amazon in 2005, suggesting tolerance to drought (Saleska et al. 2007, Science). The new study shows that those results were not reproducible, but also highlight the extreme caution that should be attached to satellite studies generally in this field, with instruments in space collecting data which is then used to infer subtle changes in the ecology of tropical forests.

In contrast to the 2007 paper, Oliver Phillips, myself, and others, published a paper in Science last year, using ground observations from across the Amazon, showing that while the 2005 drought did not dramatically change the growth of the trees compared to a normal year, as Samanta et al. also show, the deaths of trees did increase considerably. The new study of Samanta et al. does not contradict the Phillips et al. study, which itself shows the Amazon is vulnerable to drought via impacts on tree mortality. The Phillips et al. paper showed that remaining Amazon forest trees changed from absorbing nearly 2 billion tonnes of CO2 from the atmosphere annually over recent decades, as tree growth has been exceeding mortality, to being a large, but temporary, source of over 3 billion tonnes, from the elevated tree mortality associated with the 2005 drought event.

The evidence for the possibility of a major die-back of the Amazon rainforest is due to two factors,

1. That climate change induced decreases in rainfall in the dry season occur, and

2. The trees cannot tolerate these reductions in rainfall.

The Samanta paper does not directly address the first point; this is addressed using global circulation models (of which some, but not all, show a strong drying trend for the east of the Amazon over the 21st century). The second point is only addressed in a limited way. The critical question is how these forests respond to repeated droughts, not merely single-year droughts. The forests are of course able to withstand these single droughts (otherwise there would be no rainforest!) — it is their ability to survive an increased frequency of the most severe droughts that is critical to answer. Drought experiments, where a roof is built under the forest canopy to reduce rainfall, show that most forest trees survive a single year’s intense drought, in agreement with the ground observations in the 2005 drought, but can’t persist with repeated years of drought. The Samanta study does not address this point at all.

In conclusion, the new Samanta et al. study lends further weight to the emerging picture of the impact of the 2005 drought: that tree growth was relatively unaffected, but tree mortality increased, contributing temporarily to accelerating the rate of climate change, rather than as usual reducing it, via additions of carbon to the atmosphere from the dead trees. The mortality was far from catastrophic, but the impact on the carbon cycle was globally significant. This is hardly the ‘no impact’ of the 2005-drought on the forest suggested in various news reports.

I should add that there is considerable uncertainty associated with the models suggesting decreases in rainfall, and uncertainty as to how Amazon forests may react (especially when one considers the impacts of deforestation, logging, and fire combined with climate change impacts). But this uncertainty is being chipped away at by scientists, a task in which the Samanta et al. paper assists.

Oddly, the Boston University press release to accompany the paper was titled, “New study debunks myths about Amazon rain forests”. The opening line runs: “A new NASA-funded study has concluded that Amazon rain forests were remarkably unaffected in the face of once-in-a-century drought in 2005, neither dying nor thriving, contrary to a previously published report and claims by the Intergovernmental Panel on Climate Change.” So, have scientists, myself included, been peddling myths? Have respected journals being publishing them? Have the IPCC? The answer is no, no and no.

The reality is that the IPCC have largely ignored the papers on the model results of decreasing rainfall in the east of the Amazon, and the diverse evidence used to assess the sensitivity of these forests to such rainfall reductions. There are a couple of lines in IPCC Working Group I (“New coupled climate-carbon models (Betts et al., 2004; Huntingford et al., 2004) demonstrate the possibility of large feedbacks between future climate change and vegetation change, discussed further in Section 7.3.5 (i.e., a die back of Amazon vegetation and reductions in Amazon precipitation).”). And in Working Group II there is a now infamous single sentence:

“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 statement is not as carefully worded as it should be, and incorrectly referenced, but basically scientifically correct and defensible with recourse to the peer-reviewed literature available at the time. Rainforest persists above a threshold of rainfall, below which one finds savanna. If this threshold is crossed a landscape dominated by rainforest can ‘flip’ to savanna. Therefore a ‘slight’ reduction can lead to a ‘dramatic’ reaction. Of course, evidence of a shift to a new lower rainfall climate regime is needed, and evidence of large areas of forest close to that rainfall threshold would be required for the IPCC statement to be reasonable; there is ample published evidence for both.

Overall the conclusions in the IPCC 2007 Fourth Assessment Report are strengthened (because the anomalous result of the Saleska et al. 2007 paper appear to be at fault), not weakened, by the new Samanta et al. study as their press release implies.

Update: Saleska responds, pointing out that a) their 2007 paper is not contradicted by Samanta et al. (2010); b) nor is the IPCC report weakened by either paper. Confused? Then read what he has to say: here.

Reader Interactions

235 Responses to "Up is Down, Brown is Green (with apologies to Orwell)"

  1. “the message is communicated that we are partisan political hacks and shouldn’t be trusted because we are obviously dishonest in denying that. You might see the problem here. – gavin”
    Reference: “Fighting Identity” by Michael Vlahos, page 80: “Those who critically examine sacred narrative are of course always heretics”.
    But what Vlahos means by “sacred” isn’t what most of us think of when we use that word. To Vlahos, “The Market” and “The Iraq War” are sacred narratives. To Vlahos, YOU, RC, are trying to CHANGE THE IDENTITY of the American people. That is tantamount to a religious conversion.
    Now how else would a preacher of the old religion of “Fossil fuels are good $$$$$” see us besides as all those bad things?
    I am only the messenger. It is Vlahos’s opinion, not mine. I hope I have understood him correctly so far. I am on page 114. Vlahos is difficult reading.

    From me: Anger should be expected; but anger may be the first stage of learning. Luckily, we have the First Amendment.

  2. “[The IPCC] is still not advocating for a specific policy.” – Gavin.

    Are we splitting hairs here? The IPCC is clearly an advocacy group over and above its scientific theorizing and resulting conclusions. Note it does not lay out for anyone’s consideration the policy of non-mitigation, and why should it given its beliefs? I don’t recall reading about any objections from the IPCC’s rank and file (though there may well have been some) to its acceptance of the Peace Prize, a political award if ever there was one. I get it that many in the organization (and here) would prefer it to be viewed as an objective, dispassionate group simply following the evidence to its logical ends — what conceit could be more flattering to a group of scientists? Pachauri, though, has no qualms about advocacy, and he is the relevant party, no?

    [Response: Read the whole comment thread, we went through all this before. – gavin]

  3. @ Geoff Wexler #226

    It now seems to be official policy of Ukip (United Kingdom Independence Party) that AGW does not exist.

    I noted recently that Lord Monkton has joined Ukip, and seems to be one of their advisers on climate/energy.

    What I find interesting is that, as far as I know, my own Ukip MEP (Member of the European Parliament) Ian Coleman, for the Southwest Region is pretty sceptical, but has not talked to the people at the Hadley Centre, which is situated in Exeter, so the scientists he doubts are his own constituents, and if he wanted to talk with them, as an MEP, he would be happily received by the top people there.

    Ditto, Giles Chichester, the Conservative MEP (and fairly sceptical) for the Southwest has also not talked to Hadley. Chichester seems to have a problem with Hadley/Met Office because they did not predict the cold weather over Christmas.

    (I am corresponding with all my Southwest MEPs, to check if they are sceptics – and if so, have they talked to Hadley)

  4. Walt the Physicist #212

    Ed Witten. Philip Anderson. Frank Wilczek.

    Ever seen any of them on Oprah…Or anywhere else in the media for that matter?

    Who are they? They are the highest ranking physicists according to their h-index (well they were in 2008, the most recent measure I could find in 5 minutes of googling.)

    Being a physicist I’m sure you’re familiar with their work but I confess – as an ecologist – I hadn’t heard of any of them. Still they are evidently doing well, Witten has an h-index of 110 & has more than 40 papers with 100+ citations.

  5. Jean B (1979): “Ergo, they didn’t use fossil fuels despite having a growing and vibrant economy.”
    Did you read the end of my comment ?

    BPL: You don’t know your Roman history. They very much knew about both coal and oil, both having been described by Greek philosophers and also studied by Roman philosphers (e.g. the Plinies). There was an ancient-world debate over using machinery, since 3rd century BC Alexandria had seen a primitive steam engine invented. They never used steam on a practical scale, but they had a debate about machines versus slaves. They decided in favor of slaves. Not only was there a huge and economically important slave trade, but slaves were essential to agriculture and comfortable living for the upper and middle classes as well. And what would you do with the suddenly-unemployed slaves? Kill them? Let them starve to death? Can’t settle them in North Africa because there isn’t enough colony space. In short, they decided–very consciously–much the way you’ve decided about fossil fuels–“That’s how things run, and it’ll be a disaster if we change it.”

  7. Jean B (193),

    The difference in lifespan between modern and ancient cultures was primarily due to infant mortality, not the very real difference in medical technology. I imagine doing away with the widespread infanticide by which Rome controlled its population may have had something to do with why the lifespan increased later on. Well-designed sewers helped, too. They were using plenty of fossil fuels in 19th century London, but infant mortality took a long time to decrease. Seems more babies survive when you feed the poor.

  8. AB (210 and many others),

    Allow me to inform you that my father, Dr. Myron Herbert Levenson, Ph.D. (chairman of the department of sociology and anthropology, Indiana University of Pennsylvania, and author of the first low-cost, paperback sociology textbook, Human Relationships, 1974), and my mother, Beverly L. Darwin Ph.D. (author of “An Operational Theory of Medical Anthropology”) were both social scientists. I grew up reading ethnographies. And you know what? I NEVER ran across a social scientist who did what you do–arguing with the group being studied about all the things they’re doing wrong. For all their other faults, one thing the old school of Boaz and Mead had down pat was nonjudgmentalism–the social scientist was there to observe, record, analyze, and interpret–not to interfere. You don’t act anything like an anthropologist or a sociologist. You act like a missionary. And, evangelical Christian though I am, that’s not a compliment.

  9. 251 BPL: I imagine doing away with the widespread infanticide by which Rome controlled its population may have had something to do with why the lifespan increased later on.

    The first time I have to disagree with you, BPL ;) The abandoned babies tended to end up as slaves, companions for other children, or were adopted by childless couples, hence the abandonment took place in very public places (the well travelled Velabrum, and Olitorium with its nursing columns were the most used locations). Sorry for the OT.

  10. Sorry, I added to the noise ratio another comment on Gilles before noticing that Saleskas had joined the fray here with a retort to Samanta et al. This could get interesting, so could we all please stay on topic for a bit, or pipe down?

  11. Three comments about reordering much of this:

    First, with Scott Saleska joining the discussion it is time to recognize that the principal author of the Samanta paper is Ranga Myneni. Why Samanta stepped up and took the hit is an interesting point, pushing grad students in front of the bus is an ancient, but unethical, tradition, on the other hand, some of them just like to play in traffic.

    Second, the whole Gilles back and forth points out the need for threading the comments.

    Third, Eli STILL wants to know why the Amazon modeling studies are not being discussed. Have they been discarded as unreliable? If so why?

  12. 247 Chris S, you forgot one more important name – Jan Hendrik Schön, receipient of the Otto-Klung-Weberbank Prize for Physics in 2001, the Braunschweig Prize in 2001 and the Outstanding Young Investigator Award of the Materials Research Society in 2002. During his best year he coauthored about 50 articles! By now he would have surpass all the fellas you mentioned. Too sad he was exposed to rig his experimental data by just one Princeton Prof while hundreds of peers were either silent or supportive. Chris, there is unspoken requirement in academia and publically funded research labs for those of us who do natural or applied sciences to publish at least 2 – 4 articles per year in the peer reviewed journals. To the defense of promotion committees it is really difficult to judge quality of work, it is much simpler to judge by quantity. So, majority comply and publish whether they have something to say of don’t. Few publish only when they really discover something worthy. And some produce fantastically large number of publications. Those fellas have citation index soaring just because of mere number articles. Who can tell the quality? Sorry for long post, I thought you would be interested in sharing experiences. How is it in ecology?

  13. @258 I would echo CM, might the sociological/energy/etc. discussion move to perhaps the IOP thread?

  14. [Response: It is also worth stating that this was an aberration, and has stopped. The statement on scientific openness by the then-head of NASA, Michael Griffin, is the ideal that is (mostly) lived up to. – gavin]

    Yes, in those days, climate scientists from other agencies were getting “pressure” too, not just NASA- cited from peer review:

    “A widely publicized example involved James Hansen, PhD,
    director of the National Aeronautics and Space
    Administrations’s (NASA’s) Goddard Institute for Space
    Studies. A vocal spokesperson on the urgency of
    taking action on climate change, Hansen was warned
    of “dire consequences” by a low-level agency public
    affairs political appointee if he continued to make
    such statements.”

    “Other federal climate scientists have reported similar pressure.”

    Rest and Halpern American Journal of Public Health | November 2007, Vol 97, No. 11

    http://ajph.aphapublications.org/cgi/content/abstract/AJPH.2007.118455v1

  16. > CM says: 19 March 2010 at 7:47 AM
    > Sorry, I added to the noise ratio another comment on Gilles before
    > noticing that Saleskas had joined the fray here with a retort to
    > Samanta et al. This could get interesting, so could we all please
    > stay on topic for a bit, or pipe down?

    Oops, dagnabbit, me too. Saleska? Where? What’d he say? Good grief, it was right before the pager rolled over, too, and got pushed back to the previous page by all this blithering. Can we put a cork in Andreas or give him his own topic over at Deltoid or, um, quit taking his bait. I promise….

    Thank you Dr. Saleska for commenting. Thank you CM for noticing.

    Can we restart with this one?
    It’s: Comment by Scott Saleska — 18 March 2010 @ 9:13 PM

  18. This topic seems to have been totally derailed. Could we institute a thread purely for Gilles, Andreas Bjurström and co who can’t seem to prevent themselves from hijacking any and every thread. (Maybe resurrect the open thread?)

    Is Eli Rabett the only person who noticed the comment from Scott Saleska, which sticks out like a sore thumb because it is the only comment relevant to this topic out of the last 100 or so comments, from what I’ve seen. (Well, I might be exaggerating a bit, but then again maybe not.)

    With all the interest in the wonderful Amazon region over the decades, I’d have thought there’d be a whole lot more information around. But it looks like climate and the Amazon is a whole other new area for research.

    If anyone who has expertise is able to comment on Saleska’s post or otherwise add to the main topic, that would be excellent.

    [Response: Agreed. All OT comments should now go to the new open thread. – gavin]

  19. Ray: “2)Scientific consensus has nothing to do with panels or polls. It is measured by what techniques, ideas and theories are used or implied in work being published and cited.”

    It is also accepted because IT WORKS!

    If it doesn’t, it doesn’t find a consensus. Rather like GCR effects on cloud seeding in the earth’s atmosphere.

  21. [Response: It is also worth stating that this was an aberration, and has stopped. The statement on scientific openness by the then-head of NASA, Michael Griffin, is the ideal that is (mostly) lived up to. – gavin]
    _______________________________________________________________________

    Another peer reviewed statement which perhaps sheds a bit more light…

    “””Environmental geoscientists working within government agencies usually are restricted to existing institutional means of distribution or communication with external agencies or the public… (see Nield 2008)”””

    Geological Society, London, Special Publications; 2008; v. 305; p. 197-209;
    DOI: 10.1144/SP305.17
    © 2008 Geological Society of London

    Articles
    Environmental geoscience; communication challenges
    David G. E. Liverman

    http://ajph.aphapublications.org/cgi/content/abstract/AJPH.2007.118455v1

  22. John Eggert (198): the fact that Jo Nova, Anthony Watts and Steve McIntyre (among other skeptics/deniers/whatever) all prominently display active links to realclimate whilst you show no such desire to extend them the same courtesy is . . . questionable.

    BPL: By the same logic, isn’t it a shame that the Journal of Evolutionary Biology doesn’t extend links to Kent Hovind’s Dinorama and the Institute for Creation Research? How discourteous can you get?

  23. J. Bowers (209) — Tacitus writes, “We drown infants born sickly or deformed.” Wikipedia adds “Three thousand bones of young children, with evidence of sacrificial rituals, have been found in Sardinia… Pelasgians offered a sacrifice of every tenth child during difficult times (as in the verb “to decimate” the population). Syrians sacrificed children to Jupiter and Juno…

    …A letter from a Roman citizen to his wife, dating from 1 BCE, demonstrates the casual nature with which infanticide was often viewed:

    “I am still in Alexandria. … I beg and plead with you to take care of our little child, and as soon as we receive wages, I will send them to you. In the meantime, if (good fortune to you!) you give birth, if it is a boy, let it live; if it is a girl, expose it.”

    …At the end of the 12th century, notes Richard Trexler, Roman women threw their newborns into the Tiber river even in daylight.”

    Note also:

    Faerman, M., G.K. Bar-Gala, Dvora Filon, C.L. Greenblatt, L. Stagerd, A. Oppenheimer and P. Smith 1998. “Determining the Sex of Infanticide Victims from the Late Roman Era through Ancient DNA Analysis.” J. Archaeol. Sci. 8, 861-865.

    “Infanticide has since time immemorial been an accepted practice for disposing of unwanted infants. Archaeological evidence for infanticide was obtained in Ashkelon, where skeletal remains of some 100 neonates were discovered in a sewer, beneath a Roman bathhouse, which might have also served as a brothel. Written sources indicate that in ancient Roman society infanticide, especially of females, was commonly practised, but that females were occasionally saved and reared as courtesans. We performed DNA-based sex identification of the infant remains. Out of 43 left femurs tested 19 specimens provided results: 14 were found to be males and 5 females. The high frequency of males suggests selective preservation of females and that the infants may have been offspring of courtesans, serving in the bathhouse, supporting its use as a brothel.”

  24. Dr. Saleska/Samanta:

    So what? You are approaching this research question as if there aren’t other plants and animals out there competing with or feeding on those whose canopy currently dominates your measurements. What if the drying of a forest stressed by seasonal high water allows it to achieve more growth? A bald cypress tree will grow way better in my front yard than it will in its natural swamp habitat as it won’t be stressed from prolonged flooding and I’m sure canopy greenness measures would support this supposition. Yet my suburbia isn’t full of cypress swamps and alligators. Strange isn’t it?

    The forest’s existing species composition is dictated by the differential success in reproduction, growth and survival of species under current climactic conditions.

    If the climate dries, sure the existing seasonally stressed forest will grow more; until it is replaced by competing plant species that can not tolerate the current levels of flooding.

    The forest will change. The edges of the forest will drawback as they are converted into savannah. Likely any level of drying will greatly exacerbate forest loss to fire as well. Maybe no more savannah, but rather more cattle pasture and hectares of cogon grass. Oh boy, what a fun future for Brazil’s greatest asset. The other amazonian habitats will change as well. Fish assemblages will be lost as river flows and flood timing, intensity and duration changes.

    Species will be lost and the world and its nutrient, carbon, water, etc. cycling will take one more step to homogeinity and loss of robustness.

    Of course it is way more complicated than this. Assembling a model of the earth’s climate from individual physical laws is child’s play compared to doing such to the unbelievable number of individual species interactions involved in forest ecology.

    Seasonally flooded savannahs like the llanos where tree survival is hampered by prolonged inundation may dry out and be converted to closed canopy forest. Palm swamps converted to dry land forest. Likewise, savannah maybe converted into brushland if it isn’t converted to soybeans first. And on and on.

    Yes, the idiots out there are crying up is down and cats and dogs are sleeping together; I’m not arguing that. Nor am I saying that getting refining satellite and aerial photographic estimates of tree growth and levels of photosynthetic activity isn’t vital research. But climate change science needs to be better married to ecology. In the past it may have been the lack of regional models and climate projections that prevented this; but no more. The IPCC’s WWF (World Wildlife Fund) citation was no mystery to me. Their ecologists are world reknown and Thomas Lovejoy and others have spent most of their careers conducting massive field experiments in the Amazon.

    Ecological changes are often more easily visible to the general public and a greater concentration on studying this may provide a way of making climate change real to a lot more folks. The die-off of the western US and Canada’s evergreen forests due to more beetle infestations due to increased winter temperatures has been a real wake-up call.

  27. > Hannity
    Wow.

    It begins:
    March 5th, 2010, 6:27 pm rmyneni rmyneni is offline
    Man On The Street
    Join Date: Mar 2010
    Posts: 1
    Default New Science Paper Debunks IPCC Claims About Amazon
    An article published yesterday (March 4, 2010) in the scientific journal Geophysical Research Letters (GRL), the authors report that Amazon forests did not green-up during the 2005 drought, contrary to a 2007 report published in the prestigious journal Science and the IPCC claims about these forest response to precipitation declines. This article corrects much of the mis-information regarding the drought sensitivity of this important biome. The abstract of our article is shown below. I hope you will find this article interesting enough to write about it and/or help disseminate the news. If you wish to talk to us about this article, please contact the first author, Arindam – arindam.sam@gmail.com

    ——
    That would be this guy?
    http://cliveg.bu.edu/people/rmyneni.html

  29. So, now Drs Saleska and Samanta will be treated to lavish vacations at exclusive resorts in exchange for an hourlong PowerPoint presentation of their weak research. Like Lindzen – but unlike Suet and Baloney – they’ll stress that none of their research was funded by political or fossil fuel industry interests.

  30. @226 – I got a message: “Sorry. The administrator has banned your IP address. To contact the administrator click here.”

    Must be a Hannity fan club only forum, though how they could tell that I’m not a fan of Hannity’s by my IP address is quite a mystery!

  31. While the ancient world did not use a significant amount of coal or “pitch”, they did burn a very significant amount of wood. Unfortunately many forests were clear cut, and the eventual erosion took place. So what ever the case, wood, coal, oil or natural gas, CO2 results. Only in the last 70-80 years, where I live have the woods grown back, after being almost cut down for firewood.

    In many high mountain areas, solar reflector ovens are now being used to cook, instead of firewood. This results in less work gathering wood, and a chance for the trees to grow.

  32. I wonder if the reason for bad PR, Orwellian references, etc. is that the #1 “vehicle” for media messages is the silver screen and most of the “Climate Disaster” movies have been so far into the realm of science fiction that the message just doesn’t get across.

    Perhaps something much longer. Like a miniseries.

    And I’m being serious here, because so much of what’s discussed in this particular thread is how cats sleeping with dogs type of information evolves — the sky hasn’t actually fallen yet, and the only =other= message is that it never will.

  34. #233 Hank – Yes, I realized my mistake. Reading the letter on Hannity’s site made me even ditzier than normal. My sincere apologies to Dr Saleska, but I’ll stand by what I wrote in regards to Samanta. It just seems like a ploy to get into some very deep pockets.

    Politicizing the science indeed!