Makarieva et al make the headlines with “Where do winds come from?” Paper

Posted: February 2, 2013 by tallbloke in solar system dynamics

The Makarieva et al story we broke on the talkshop a week ago has been hitting the headlines. From ‘the Australian’ interview with Doug Sheil via the GWPF:

NEW RESEARCH BLOWS CLIMATE SCIENCE WIDE OPEN
Graham Lloyd, The Australian

douglas-sheil

Australian scientist Douglas Sheil could turn accepted wisdom on its head with the theories set out in the paper ‘Where do winds come from?’ Picture: Vanessa Hunter Source: The Australian

THE world’s great forests have long been recognised as the lungs of the earth, but the science establishment has been rocked by claims that trees may also be the heart of its climate. Not only do trees fix carbon and produce oxygen; a new and controversial paper says they collectively unleash forces powerful enough to drive global wind patterns and are a core feature in the circulation of the climate system.

If the theory proves correct, the peer-reviewed international paper co-authored by Australian scientist Douglas Sheil will overturn two centuries of conventional wisdom about what makes wind. And it will undermine key principles of every model on which climate predictions are based.

The paper, Where do winds come from? A new theory on how water vapour condensation influences atmospheric pressure and dynamics, is not designed to challenge the orthodox view on climate science. But Sheil, a professor of forest ecology and conservation at Southern Cross University’s School of Environment, Science and Engineering, says he is not surprised that is how the paper has been received internationally.

Boiled down, he says, bad science is protecting shoddy climate models.

The paper, lead authored by Anastasia Makarieva, sparked a long-running and furious debate about whether it should be published at all. At the end of a bruising assessment process the editorial panel of the prestigious journal Atmospheric Chemistry and Physics chose to publish and be damned.

In an accompanying statement the journal editorial board said: “The paper is highly controversial, proposing a fundamentally new view that seems to be in contradiction to common textbook knowledge. The majority of reviewers and experts in the field seem to disagree, whereas some colleagues provide support, and the handling editor (and the executive committee) are not convinced that the new view presented in the controversial paper is wrong.

“The handling editor (and the executive committee) concluded to allow final publication of the manuscript in ACP in order to facilitate further development of the presented arguments, which may lead to disproof or validation by the scientific community.”

Sheil says the key finding is that atmospheric pressure changes from moisture condensation are orders of magnitude greater than previously recognised. The paper concludes “condensation and evaporation merit attention as major, if previously overlooked, factors in driving atmospheric dynamics”.

“Climate scientists generally believe that they already understand the main principles determining how the world’s climate works,” says Sheil. “However, if our hypothesis is true then the way winds are driven and the way rain falls has been misunderstood. What our theory suggests is that forests are the heart of the earth, driving atmospheric pressure, pumping wind and moving rain.”

In a blistering assessment of the paper, international climate scientist Isaac Held of the National Oceanic and Atmospheric Administration recommended that publication be rejected.

“The authors make an extraordinary claim that a term that is traditionally considered to be small, to the point that it is sometimes neglected in atmospheric models and, even when not neglected, rarely commented on, is in fact dominant in driving atmospheric circulations,” Held said. “A claim of this sort naturally has to pass a high bar to be publishable, given the accumulated evidence, implicit as well as explicit, that argues against it. I am afraid that this paper does not approach the level required.

“I have done my best to keep an open mind, but do not see any cogent arguments that overturn the conventional wisdom.”

In reply, the authors claimed Held’s logic was bad for science.

“A higher bar for unconventional ideas automatically implies a lower bar for conventional ones,” they said. “Introducing a positive feedback – relating the height of the higher bar to the number of studies that have passed the lower bar – in time, if this continues, a once-vibrating scientific community can be trapped in dogma.”

Shiel says he is not surprised at the resistance from within the climate science establishment. “These guys are under a barrage of claims every day and we are just another one,” he says. “But we are serious scientists, we have serious reasons for looking at this and if you can show us where our analysis is wrong, that’s fine, that’s how science works.

“Accepting our theory would basically mean the climate models are wrong. It wouldn’t mean that theories about carbon dioxide and greenhouse gasses are wrong.

“The basic physical issues are still there. Winds are still caused to some degree by temperature differences, global warming will still be potentially caused by greenhouse gasses. But what we are saying is one of the major reasons that air moves around the surface of the globe, and one of the main reasons that rain falls where it does, is to do with these patterns of moisture evaporation and condensation.”

For Sheil, who returned last year from working at the Institute of Tropical Forest Conservation based in the Bwindi Impenetrable National Park in Uganda, the significance of the findings goes way beyond climate-change politics.

It could have dramatic consequences for how vegetation is considered and managed. And it could have ramifications for securing future rainfall for some of the world’s most impoverished regions.

“Our theory also explains how declines in both rainfall and rainfall reliability can result from forest loss elsewhere,” Sheil says. “Such patterns have been observed in various parts of the world and are clearly of major importance for many people – for example, those who are suffering from the increasingly irregular monsoon rains in West Africa.

“I would have said Australia is a desert because of the global climate cycles, but if you do the calculations, a forest across the surface of Australia would produce forces strong enough to water it and you wouldn’t need to irrigate.

“When we look at the Amazon and ask, is the forest there because there is a lot of rain, we are saying, no, it is the other way around: the rain is there because there is a lot of forest.

“It may sound strange – forests causing wind, forests causing rain – but the physics is quite convincing.”

Climate scientists, however, still say the significance is not as great as has been claimed.

“It has now gone from a discussion about mechanism to a discussion about magnitude,” Sheil says, adding that a key objective of his work is to make climate models more reliable.

“At present the models are incorrect,” he says, “because they are missing one the key mechanisms of how the global climate works. I know it does sound amazing to say this, but once you look at these models they are not as detailed and not as smart as you would think.

“A lot of it is, they are calibrated to fit. There is a little bit of people hiding the problems, and that is bad science.”

The Australian, 2 February 2013

Comments
  1. Stephen Wilde says:

    “When we look at the Amazon and ask, is the forest there because there is a lot of rain, we are saying, no, it is the other way around: the rain is there because there is a lot of forest.”

    The Amazon. the Congo and the jungles of south east Asia are all under the Inter Tropical Convergence Zone.

    The forest bands of the mid latitudes are all under the mid latitude jet stream tracks.

    Which came first ?

    However, I do agree that forests have a thermal and hydrological impact, that the water cycle is not adequately dealt with by climate models and that the energy exchanges in the phase transitions of water are both important and under appreciated.

  2. Stephen Wilde says:

    “I would have said Australia is a desert because of the global climate cycles, but if you do the calculations, a forest across the surface of Australia would produce forces strong enough to water it and you wouldn’t need to irrigate.”

    Australia gets very little frontal activity being away from the jet stream tracks and has little height to provoke orographic rainfall.

    I think irrigation would be required.

  3. Stephen Wilde says:

    Rog, I hope I don’t seem to be ‘swamping’ the Makarieva threads with comments but the water cycle aspect has been in the forefront of my mind since well before I started commenting in public back in early 2008 or thereabouts.

    I am keen that the value of the Makarieva work be established one way or the other as soon as possible and it is not against my interests if she is shown to be correct because her work doesn’t affect the broader AGW theory in any event. It just replaces human emissions of CO2 with the effect of human treatment of the forests as another similar human caused potential catastrophe.

    To my mind such a water effect would be dealt with by the system internally in the same way as the system deals with CO2.

    If it doesn’t rain in one place it will just rain more somewhere else with a shift in the general circulation.

    As you pointed out yourself specific humidity stays much the same and solar input to the oceans is the primary cause of evaporation so the Makarieva proposal is only ever going to be matter of rainfall redistribution.

    [Reply] “I hope I don’t seem to be ‘swamping’ the Makarieva threads”
    No problem! I’m glad you are engaging with them. I hope others will join in too. I do think we need to understand their theory so we can integrate it with ours though.

  4. Scute says:

    Does this mean Amazon forests contribute to ENSO? Seductive thought but I suppose we would have noticed the winds howling across Ecuador if that were the case! Or is there a subtler answer to that?

    I have often wondered if the South Atlantic Anomaly enhances the Amazon basin total water content in line with varying GCRs. The water content does vary noticeably according to satellite gravitational anomalies. The extra water vapour in the system would then lead to more cloud cover due both to conventionally understood mechanisms and any persisting GCRs.

    I had always been luke warm about an ENSO link because the Andes are sort of in the way whether it’s the clouds that have to make their way westward or, in this case, the winds they produce. If somehow they did, then it would be the cyclical nature of their movement and intensity that would lead to variation in easterly winds sufficient to drive the Pacific currents.

    I remember a climatologist remarking on the NOAA time lapse satellite footage for ENSO saying it was, paradoxically, “a transoceanic phenomenon” (if I remember the quote correctly). He was referring to the warm ocean currents flowing westward across the north of South America and appearing to flow ‘through’ Central America before carrying on across the equatorial Pacific. Of course, it was one westward flow of winds that was driving the currents in both oceans and which flowed unhindered across Central America. Where do these winds come from? Could it be that they are flowing northwards out of the Amazon basin and arcing round the northern tip of the Andes?

    Scute

  5. mitigatedsceptic says:

    “A claim of this sort naturally has to pass a high bar to be publishable..”,..In reply, the authors claimed Held’s logic was bad for science. “A higher bar for unconventional ideas automatically implies a lower bar for conventional ones,” they said. “Introducing a positive feedback – relating the height of the higher bar to the number of studies that have passed the lower bar – in time, if this continues, a once-vibrating scientific community can be trapped in dogma.”

    Regardless of the merit of this paper, this notion of a higher bar for unexpected observations/hypotheses is utterly disreputable! One black swan should be enough!
    Science has come to a pretty pass when a supposedly honest and sincere scientist can utter such destructive advice. Held should be ashamed!

  6. tgmccoy says:

    As an old Aerial Firefighter with more than a bit of Scientific training and real world experience.
    they are on to something. I’ve seen big fire in a stand of old growth ( that has been managed.,btw.)
    Where the was little undergrowth, prescribed burns, done a clean forest, and the fire was manageable.
    What I noted, was the activity of thunderstorms in the area during,say the “Moonsoon” season of
    the American southwest. What happened in my estimation, was,again this is personal opinion,
    that a fire that is just creeping around through healthy trees, does not get intense,this is a fact.
    Also a fact is if you don’t keep a forest healthy by keeping it clean,you get big, over the hill,
    bullroaring fires. Ok the managed stands (Private usually) had wetter less wind driven storms.
    Working fires in Government stands (Usually US Forest Service) due to the “DON”t TOUCH”
    Policies of the last couple of decades, they have (with exceptions) made things worse.
    I noticed that the Storms near a fire that is in this type of fire were drier, and a bit more
    wind driven due to the addition of intense heat, and particulates added by the fuels in the fire.
    Also after a wet storm the healthy trees seem to “hold the moisture” far better.
    Note: this is purely an unscientific,undocumented,observation of a personal nature.
    However, I do think there is something to this…

  7. tallbloke says:

    MS: “Science has come to a pretty pass when a supposedly honest and sincere scientist can utter such destructive advice. Held should be ashamed!”

    read this non-technical reply to Held from Makarieva:

    Anastassia Makarieva: Science: One Bar For All

  8. w.w.wygart says:

    “It may sound strange – forests causing wind, forests causing rain – but the physics is quite convincing.”

    Sounds perfectly reasonable to me and seem to be what we should already know goes on when ever you try it.

    When Charles Darwin visited Ascension Island in 1836, he described it as arid and treeless, and the water supply for the British garrison there was always a worry. Having only risen up out of the Atlantic relatively recently it had been colonized by only a few species of grasses and plants. The islands weather system, dominated as it was by the St Helena High tended to bring little precipitation to the island. It was a ‘desert’ island.

    Since the 1840’s a sustained effort at afforestation [these were all ‘introduced’ species of plants BTW] lead by Joseph Hooker [at Darwin’s suggestion] lead to the creation of a permanent cloud forest ecosystem on the island by the 20th century, thus securing the islander’s water supply. The islands largest peak, originally know as White Mountain, is now referred to as Green Mountain.

    W^3

  9. Roger Andrews says:

    “When we look at the Amazon and ask, is the forest there because there is a lot of rain, we are saying, no, it is the other way around: the rain is there because there is a lot of forest.”

    This is a testable hypothesis:


  10. tallbloke says:

    Heh, thanks Roger A. There are various ways to interpret that plot. On balance I think I’d go with the idea that rainfall measurements agglomerated over such a wide area might not have been so well organised in the mid 1800’s. The plot from 1900 onwards seems to tally with the theory reasonably well.

  11. Roger Andrews says:

    TB: Yeah, pity about the data before 1900, although the rainfall records actually don’t look too bad before then.

    I’ll look around for some more examples. The problem is getting data on forest extent.

    [Reply] Lol, enjoy the hunt for “the roebuck in the thicket

  12. tchannon says:

    Water burden in the atmosphere will rise to a limit case if there is no way out but it only take uplift to bring fallout, then in rush the predators on wet land.

    I wonder how many have twigged the connection with rain systems forming over ocean? The extreme cases are hurricanes and typhoons. For that matter water spouts forming over sea.

    If Makarieva explains an internal detail to do with evaporation creating gas and gas vanishing again, all well and good, but I am very unhappy about a treehugger justification, a political agenda.

    You get water and heat, convection is there immediately. Was getting this earlier here when I was doing some chores. Seem to be out of trees inside the house.

  13. Roger Andrews says:

    TB:


  14. tallbloke says:

    Thanks Roger A: No argument there, except Makarieva has stats on rainfall for the Amazon basin which disagree with yours.

  15. Roger Andrews says:

    They’re not my rainfall stats, they’re GHCN rainfall stats.

    Could you point me towards Makarieva’s? I can’t find them in any of the links.

  16. tallbloke says:

    “According to recent analyses, during 1973-2003 precipitation in the Amazon River basin was declining at a rate of 0.3 percent annually, which means a trend of about 10 percent for the entire period. This does not include the most recent devastating droughts of 2005 and 2010. In the meantime, deforestation in the basin has amounted to about 30 percent during the same period. Deforestation mostly disturbed southern and south-eastern parts of the basin, where the precipitation/evaporation is less than in the basin core. ”

    No link given for ‘recent analyses’ unfortunately.

  17. Roger Andrews says:

    TB: Thanks. I think this is the paper:

    http://onlinelibrary.wiley.com/doi/10.1002/joc.1791/pdf

    “Rainfall spatio-temporal variability is studied based on a varimax-rotated principal component analysis (PCA)”. I think I’ll stick with GHCN.

    shows three precipitation records in the Amazon Basin – Belem at the mouth of the Amazon, Manaus in the middle and Rio Branco near the west edge. Rio Branco is in the middle of a large deforested area.

  18. Douglas Sheil says:

    thanks for the exposure — I should begin by saying that I am not 100% happy with this article. It suggests I am Australian and it suggests I have some hostility to climate modellers — neither is true.

  19. Douglas Sheil says:

    Looking at the thread I see you are discussing evidence so hope you may value the post I just made at JC’s:

    The theory is published: now we need evidence …

    Much of the discussion has been about theory. But I suspect many readers are interested in evidence. Dr Held too asked for “evidence” to pass his “high bar” – we rejected the argument as a point of principle. The question at issue then was whether we had presented a case coherent and interesting enough to answer: it is a theory. Theories come first the evidence comes later.

    But that does not mean we don’t have extraordinary evidence.

    We wrote a little about this in the paper (most points below can be explored by looking at the reference list there or at http://www.biotic-regulation.pl.ru/index.html), but it may be useful to highlight a few again here so you can make your own assessments. What is our evidence so far? How does out theory match reality?

    For me the most powerful evidence comes from looking at how rainfall varies as we travel inland from the coast (over relatively flat terrain): Why does rainfall not decline over forest? It declines over non-forest in a relatively constant manner that is easy to understand (This seems to be a global pattern: see the figure in my previous blog here http://judithcurry.com/2011/03/30/water-vapor-mischief-part-ii/). Recycling is not an explanation – it would reduce the rate of decline but it could not prevent it. There is no alternative explanation at present.

    This effect – the drawing of rain into continental interiors – requires a biologically functioning forest so we would predict that the effect will be smaller over boreal forests in deep winter (when the forests are metabolically inactive and not transpiring moisture). Observations support these predictions. There is no alternative explanation at present. See, e.g. Makarieva, A. M., Gorshkov, V. G., and Li, B.-L.: Precipitation on land versus distance from the ocean: evidence for a forest pump of atmospheric moisture, Ecol. Complex., 6, 302–307, 2009.

    Our paper (discussed in this post) shows that we can estimate the power of global atmospheric circulation. This is the first ever such estimate developed from first principles and, though intended as a rough estimate, is remarkably close to the measured values. No alternative theory can currently explain this value.

    Where we have good data on forest loss and rainfall change there are some observations suggesting a regional decline in rain regularity (as we would predict). See E.g. Webb TJ, et al. 2005. Forest cover-rainfall relationships in a biodiversity hotspot: The Atlantic Forest of Brazil. Ecological Applications 15: 1968–1983.

    The work by Anastassia and co. (not me!) on hurricanes is also impressive: it shows that the condensation generated pressure gradients can give a physically and analytically consistent model of how such storm systems function and can be used to estimate several characteristics from first principles. E.g. Makarieva, A. M. and Gorshkov, V. G.: Condensation-induced kinematics and dynamics of cyclones, hurricanes and tornadoes, Phys. Lett. A, 373, 4201–4205, 2009.

    So the score-card so far is 7:nil in favour of our theory (I rate the hurricane work as three points … but even if you don’t 5:nil is a good margin). That’s a good score line. Extraordinary? Well I acknowledge too that the search for counter-evidence is in its infancy.

    So now the theory can and should be tested further. All those who think it is right, all those who think it is wrong and all those who are uncertain but recognise why it matters, can I hope agree that the ideas should be tested. That is a common goal.

  20. tallbloke says:

    Douglas: or should I call you Doug and Sheila? 🙂

    Due to the strong division along political battle lines and the heavy regime of regulation and the threatened tax implications of proposed policy, the climate debate is very heavily polarized and … err… robust… in Australia. ‘The Australian’ is on the more sceptical side of the debate. If you hadn’t realised this when you did the interview, you were a … babe in the wood… 🙂

    Thanks for continuing to contribute here, we appreciate it enormously when working scientists engage with our examination of their science. Your list of supporting evidences is impressive, though as you said, the search for counter evidence is not so well developed.

    Peter Berenyi put some up on Judy’s site which Anastassia replied to. I’ll reproduce the exchange here because her replies answer some of the points raised here too, though in a pretty technical way in places. She seems to have missed answering points 2) and 4)? If you could add any explication for laymen it would be most welcome!

    Berényi Péter | February 2, 2013 at 8:22 am | Reply
    Dear Dr. Makarieva,

    how do you explain several prominent features of the global wind field?
    1. winds are strongest above mid latitude oceans
    2. there is a sharp drop in wind energy at continent boundaries
    3. winds are low above continental areas except over deserts
    4. winds are weakest over the tropics where precipitation rate is highest
    5. the windiest continent is Antarctica, also the driest

    see Annual 50 m Wind Speed (July 1983 – June 1993)

    Anastassia Makarieva | February 2, 2013 at 11:35 pm | Reply
    Thank you for your question. Let me give some context to my replies below. Our theory constrains the rate at which the kinetic energy of winds is generated. In hydrostatic equilibrium this rate q defines the work per unit time of the horizontal pressure gradient, see Eq. (4) in the post. It is given by u∇p, i.e. it is proportional to the horizontal velocity component u_p that is parallel to horizontal pressure gradient.

    Thus, Eq. (4) does not constrain the velocity component that is perpendicular to the pressure gradient (e.g., the geostrophic wind). Nor does it separately constrain u_p and the pressure gradient, only their product. In order to find all the velocity components one equation is obviously insufficient. So, while q in (4) is proportional to precipitation P, this equation cannot be interpreted as a kind of rule of thumb “where precipitation is high, wind is strong”. Eq. (4) provides a constraint on the generation of dynamic power, but we certainly need additional information on dynamics as per Euler and N-S equations to solve the problem in full.

    After this preambule, I do not think that my replies below will be anywhere surprising.
    1. Strongest winds in midlatitudes. Unlike the Hadley cell, the midlatitude circulation cell goes against the gradient of solar power (with the ascent occurring where there is less solar power and hence less potential evaporation). This “forced” cell is heavily impacted by the dynamic processes in the much larger tropical area, with geostrophic winds enhanced by a larger Coriolis force at a higher latitude.
    2. there is a sharp drop in wind energy at continent boundaries
    3. winds are low above continental areas except over deserts
    Surface roughness is higher on land than over the ocean, and is minimal on land in deserts. Note that condensation-driven winds, like any circulation, have an ascending branch (where it rains) and a descending branch (where it is dry). So the existence of winds in deserts per se is not an argument against condensation-driven dynamics.

    5. the windiest continent is Antarctica, also the driest.
    Antarctica is outstanding not only in being the driest. Unlike in Hadley cell where the ascent and hence precipitation occur over a longer radius (because of low latitude) than the descent, in the polar cells situation is the opposite. So there is an opportunity for the dynamic power that is generated in the midlatitude rain belt of the ascending air to be concentrated over a relatively small area in the area of descent over the poles. Concentration of wind energy produces large local winds over the poles.

  21. Ray c says:

    Trees make wind and rain.

    What does the water vapour condense onto above forests? There are limited supplies of aerosols coming in on oceanic winds , sometimes. ! Is there always enough of them present for condensation?
    Especially where the trees are evergreen, but deciduous trees and other types of vegetation too produce gasses called terpines and isoprenes. These go through gas to particle conversion, solid and liquid mass is formed, and they are extremely hygroscopic. They attract water condensation vapour onto their surfaces. In other words the trees have evolved to produce water attracting molecules. They make it rain. Macros scale from mycrophyisacal scale dynamic process.

    Anyway an increase in wind speed due to the increased transpiration from evergreen trees must happen if they are creating mass from photosynthesis (increased density of warm rising gasses of plant metabolism which actually assists condensation or provide sites for condensation (more increased density) Trees make wind and rain don,t they, in part of their biotic regulation.

  22. Ian W says:

    This is an interesting concept. Perhaps there should be some involvement from botanists in this area. Plants and transpiration have been covered in detail with metrics for sap rates etc. and some of the figures can be surprising for people that have not studied the area. Plants try to maintain a steady temperature and bring nutrients from the soil by taking in water at their roots and evaporating the water from the stomata in their leaves. Plants need therefore to reach down to the water in the soil to obtain the required water for this cooling and transport of water. A broad leaved mature tree in summer can transpire water at the rate of 200 liters an hour this is a lot of water especially if a forest of several million tress is considered. Plants adapt to the amount of water available fir trees with leaves adapted with thick cuticles transpire significantly less at around half a liter an hour.

    If two similar coastlines with similar ambient winds could be compared one with a forest of broadleaved trees the other with conifers it may be possible to use them as ‘control’ for validation of the hypothesis

    Similarly, comparison of an area that was broad leaved rain forest that has been changed to a monoculture palm plantation may show an alteration in rainfall and wind patterns. Unfortunately, there are many such areas.

  23. Ray c says:

    “how the world’s climate works,” says Sheil. “However, if our hypothesis is true then the way winds are driven and the way rain falls has been misunderstood. What our theory suggests is that forests are the heart of the earth, driving atmospheric pressure, pumping wind and moving rain.”

    Staring with the basics, What role do aerosols play. The water cycle would be very different without them, in fact, Would there be one?

  24. Douglas Sheil says:

    ” If you hadn’t realised this when you did the interview, you were a … babe in the wood…”
    I certainly had an inkling – but I gave all the context and caveats. I also said I was not able to answer several questions. Still I guess controversy is a big part of what makes this news: and it is certainly contraversial

  25. Douglas Sheil says:

    You asked for an explanation to
    2. there is a sharp drop in wind energy at continent boundaries
    4. winds are weakest over the tropics where precipitation rate is highest

    I think Anastassia thought she had answered by extension.
    Let me try:
    2. Surface roughness is a break on systems building up energy. Also the fact that the forest based evaporation system is not “on” during the nightime but depends on transpiration during daylight. Both of these prevent formations from building up high momentum as they can over oceans.
    4. this is the corollary of the strong wind at the poles effect (5). The circulation is constrained over a smaller area at the poles and a larger area at the tropics. There are fairly strong winds near the equator but variour factors (Coriolis etc) tend to draw them away to higher latitudes if they develop into major storm systems.

    I’m not sure if the heat (as opposed to our condensation) arguments would offer anything much different.

  26. Douglas Sheil says:

    The point about aerosols is certainly interesting. There has been a lot of research on this. Certainly there are many and various materials and compounds that have been examined as condensation nucleii.
    Arecent one by Pohlker et al. Science 2012 – 337, 31: 1075-1078 is especially intriguiging as it seems that that the Amazon forest emits potassium salts into the atmosphere.
    Here … http://web.mit.edu/qichen/www/pdf/Poehlker_Science2012.pdf
    Hope that helps.

  27. Douglas Sheil says:

    Ian W
    I am a vegetation ecologist.
    Indeed – this was essentially the angle that Daniel and I came at the issue from.
    See the text we wrote for other biologists here (unfortunately without the figures):

    Click to access HowForestsAttractRain.pdf

    Hope it is of interest

  28. Roger Andrews says:

    “When we look at the Amazon and ask, is the forest there because there is a lot of rain, we are saying, no, it is the other way around: the rain is there because there is a lot of forest.” As I noted earlier, this is a testable hypothesis.

    Here are a couple more plots that test it. Again there’s no relationship between rain and forest cover:


  29. tallbloke says:

    Yikes, lookk at the loss of forest in the Philippines. Doesn’t seem to have affected rainfall much. Monsoon too big to be affected?
    http://opinion.inquirer.net/5809/protect-philippine-forests
    Large-scale, export-oriented commercial logging was introduced by American colonizers. At the start of the American occupation in the 1900s, the Philippines had 21 million ha of old-growth forests covering 70 percent of the land area. Logs were exported mainly to the United States and used to support the mining industry set up by the Americans. By the 1940s, only 9 million ha of forests covering 30 percent of the Philippine land area were left.
    Deforestation further worsened during the Marcos regime. The logging industry was controlled by foreign companies and the local elite, some even holding public offices. Timber Licensing Agreements (TLAs) were given out by the Marcos regime to loyalists. From 1965 to 1986, the Philippines lost 7 million ha of forests.

  30. Douglas Sheil says:

    Roger Andrews
    Yes at these gross aggregate scales you dont see it. We need to look at local patterns (best as you move inland as we are talking about flows in from the ocean). The references above include various examples where this has been done.
    See e.g. the figure in my previous blog here http://judithcurry.com/2011/03/30/water-vapor-mischief-part-ii/
    But we do need more work on this. I understand that there are a number of studies underway that will help clarify these effects.

    p.s. Sorry — I see I pasted the wrong citation yesterday into the seasonal effect link (which is also a tested prediction).
    I meant this one
    Makarieva, A. M., Gorshkov, V. G., and Li, B.-L.: Revisiting forest impact on atmospheric water vapor transport and precipitation, Theor. Appl. Climatol., 111, 79–96, doi:10.1007/s00704-012-0643-9, 2013.
    Dont know if you can access this but I can send to Tallbloke if you like.

  31. tallbloke says:

    Douglas: I’ll try to access it tomorrow. If not, I’ll mail you.

    Forestry isn’t just about rainfall but what happens with the water after it lands.
    from the same link:
    Effects of deforestation
    Disasters such as floods and landslides that result in loss of life and livelihood are the most visible and devastating effects of forest destruction. The most unforgettable of these is perhaps the Ormoc flood on Nov. 5, 1991, which killed almost 8,000 people.
    The Citizens’ Disaster Response Center noted that at least 27 floods and 17 landslides happened each year in 2000-2010. In the same period, at least 1.6 million people were affected each year by floods, and 24,212 by landslides. Damage to agriculture and infrastructure ran into tens of millions of pesos a year.
    Human rights violations related to deforestation include land grabbing, militarization, abuse of the free and prior informed consent requirement and killings. Indigenous peoples are the usual victims because their ancestral domains are generally found in forests.
    Antilogging leaders such as Alberto Pinagawa of Misamis Oriental and even forest workers like Elpidio Malinao of UP Los Baños and botanist Leonard Co were killed while actively involved in forest protection. Joey Estriber, a known antilogging advocate in Aurora, is a victim of enforced disappearance.
    Other effects of deforestation are loss of biodiversity and continuing threats to endemic plants and animals. The Philippines has 6,091 endemic plant species and 591 endemic animal species. Among the animal species, 151 are endangered.

  32. Douglas Sheil says:

    Tallbloke
    Just mailed you the PDF.
    Certainly forests have many other values and influences. That is what a lot of my work has been about.

  33. Douglas Sheil says:

    Let me take advantage of the interest and exposure here and offer a link that may interest some of you about these bigger forest issues (not climate). Its a video we made about, and for, forest communities in Indonesian Borneo. We made an English version too:
    see http://www.youtube.com/watch?v=eVIsN5-C1AA
    Best wishes
    Douglas

  34. Ray c says:

    Douglas Sheil says:
    February 3, 2013 at 10:49 pm
    “The point about aerosols is certainly interesting. There has been a lot of research on this. Certainly there are many and various materials and compounds that have been examined as condensation nucleii.
    Arecent one by Pohlker et al. Science 2012 – 337, 31: 1075-1078 is especially intriguiging as it seems that that the Amazon forest emits potassium salts into the atmosphere.
    Here … http://web.mit.edu/qichen/www/pdf/Poehlker_Science2012.pdf
    Hope that helps.”

    Thank you for your interesting reply Mr Sheil. Especially Intriguing as it seems that the Amazon forest emits potassium salts into the atmosphere.

    So trees can increase their net primary product, by increasing fertiliser salt out put and produce gas to particle aerosols for the transportation method , and make it rain , Oh! And of course cause wind to move it inland too, to grow more trees, amazing. Very interesting stuff to this layman, thanks.

  35. tallbloke says:

    At last, a ‘good news’ forestry story, under my nose in the UK
    http://www.bbc.co.uk/news/science-environment-21275432

  36. tallbloke says:

    More good news:
    http://www.rainforestrealities.com/newsroom/press-releases/app-commits-to-an-immediate-halt-to-all-natural-forest-clearance/
    JAKARTA, 5 February 2013 – Asia Pulp & Paper Group (APP) has announced an end to the clearing of natural forest across its entire supply chain in Indonesia, with immediate effect.

    From February 1st, all of APP’s suppliers have suspended natural forest clearance whilst independent assessments take place to identify areas of high conservation value that will be protected through a long-term management programme.

  37. Eli Rabett says:

    Amusing how video shows that this is just a bag of wind going in the wrong direction. When clouds form by condensation they expand because of the energy available from the heat of condensation.