Bishop Hill Whither DeSmog?
Jun 2, 2015 Climate: WG2 GWPF Greens One of the very first briefing papers issued by GWPF was on the greening of the Sahel. The Foundation's then deputy director Phillip Mueller put forward the idea that rather than making droughts on the fringes of the Sahara more severe, climate change was, if anything, actually making things better. This observation was suitably couched in caveats that noted, quite correctly, that we really couldn't say one way or the other what would happen in the future.
I don't remember the paper garnering a lot of attention at the time, but there was a typically wild-eyed response from those mini-Ehrlichs at DeSmog, which included this shot from the hip:
It is wild speculation to assert that any recovery in the Sahel is a result of global warming and to dangle the prospect of a future green Sahara is the exact opposite of the message provided by Mueller's reference on the matter. However welcome the re-greening of parts of the Sahel, it cannot be relied on.
How amusing then to read in the Times that a team of mainstream scientists led by Rowan Sutton are now making just this claim:
Climate change has achieved what Bob Geldof and Live Aid failed to do by ending the drought in the Sahel region of Africa that killed more than 100,000 people in the 1980s, a study has found.
Rising greenhouse gases caused rains to return to the region south of the Sahara, from Senegal to Sudan, boosting crop yields since the 1990s and helping the population to feed itself without relying on foreign donations.
Now the study is a GCM-based attribution study, and as readers here are well aware GCMs don't do rainfall in any meaningful way, so I take the claims with a large pinch of salt. Nevertheless, it's going to be fun to see what DeSmog makes of them. Is a "debunking" of Rowan Sutton on the way or are they going to admit that GWPF might just have had a point?
Reader Comments (76)
Entropic man, out of respect to our host, I am going to keep this brief and polite. Sudan split on religious lines. North Sudan is run under sharia law, but people in South Sudan are either Christian, or Animist. Rwanda's dreadful violence arose from tribal hostility between the Hutu population and the Tutsi population. Another commenter has already disposed of your remarks about Syria.
Jorge, if you go to this site, you will see a graph of how increasing CO2 increases photosynthesis (assimilation rate), whilst simutaneously decreasing stomatal conductance. Transpiration (water loss) follows stomatal conductance.
www.scopenvironment.org368 × 311Search by image
Figure 10.5 The relationship between assimilation rate (A), stomatal conductance for CO2 (gs) and ambient CO2 concentration (Ca) for unstressed Populus deltoides.
Sorry I don't know how to insert a link.
EM: well, at least you read the comments, which is more than could be said of others. Now, the question has to be, do you fully understand them? If not, is the problem with your comprehension or in the writer’s flawed attempts at communication? The best answer to that would be from responses of others to the comment; sadly, you are the only one to respond to my comment – a nil response could be used, but involves too many suppositions (i.e. they actually read it; they are happy, and do not consider further comment necessary; it is too far beneath contempt to offer argument; etc.) to make a realistic conclusion – so, perhaps we should compare your response to comments that have other responders. I’m sorry, but a quick review does suggest that you might be having problems with comprehension.
Craig
My sarc antennae were in for servicing. Sorry!
Don Keiller
I did a quick literature search overnight and the PNI hypothesis is still very much in play. We'll probably have to agree to disagree on that. On a purely personal note, the name Idso popped up several times. That rather reduced my confidence in the negative view.
Let's talk about temperature. My plant physiology is rather rusty, but I agree with you that for C3 plants increased CO2 leads to decreased average stomatal opening and reduced transpiration. This would indeed allow the plant to reduce its water uptake and make it slightly more drought tolerant.
In the short term this will increase yield if the extra nitrogen can be made available, which is by no means a given for a Third World farmer (Their was no need for sarcasm), or for a civilisation under pressure to reduce its energy use (ie the Haber process)
The longer term problem is that in most farming areas increased CO2 will be accompanied by increased temperatures.The reduced transpiration which improved drought tolerance will reduce cooling. This has two consequences.
Firstly the maximum temperature tolerance of the plant is reduced. This makes the death of the entire crop more likely.
Secondly, increased photorespiration will cancel out increased photosynthesis, limiting yield.
Over the long term the consequences of increased CO2 are more likely to be negative than positive.
Over a couple of decades, you may well be right. Over a couple of centuries you are very probably wrong
EM
Do you have any hard information as to when all these downsides kick in? And since the current temperature range of the planet is around 100°C I'm not sure how an average increase of 2°C is going to be all that significant either way.
It seems that you are assuming:
that plants cannot adapt;
that the temperature increase is going to be outwith anything mankind has adapted to before;
that we have suddenly lost our scientific skills (though looking at climate science that is increasingly possible) and cannot develop plants that are capable of coping with that increase ... or just as likely with the inevitable fall into a little ice age which some reckon could be with us in 10 years.
Always there is this assumption that nothing good can come of a couple of degrees of warming when the whole history of mankind says you're wrong.
Owen Morgan, TTY
Both of you are only looking at the surface level of the problems. Look a little deeper.
In a society with sufficient resources there is less survival competition between groups and less reason for violence.There will be rivalry, but not violence.
Now stress that society. The competition for resources becomes much more intense and conflict ensues. For most people the banner they fight under is ideological, but the underlying cause is the same.
The link between climate change as a stressor and conflict is still under discussion and may not apply in every case.
For Rwanda, in particular, the death toll included 800,000 Tutsis, but also a number of disabled or otherwise unproductive Hutus. This was an attempt to reduce the number of mouths to feed.
Entropic man, I did Natural Sciences at Cambridge, followed by a PhD in Plant Physiology and a couple of post-docs, one of which was specifically on photosynthetic mechanisms. However I am not going to argue from authority, rather from established facts.
To addess your two key points
"The longer term problem is that in most farming areas increased CO2 will be accompanied by increased temperatures.The reduced transpiration which improved drought tolerance will reduce cooling. This has two consequences.
"Firstly the maximum temperature tolerance of the plant is reduced. This makes the death of the entire crop more likely."
No increased CO2 increases temperature tolerance, the danger comes from increased temperature in the absence of increased CO2- which according to the alarmist paradigm is impossible.
"Secondly, increased photorespiration will cancel out increased photosynthesis, limiting yield".
NO - again increased CO2 reduces photorespiration by a greater amount than increased temperature by reducing RUBISCO oxygenase activity- that is why C4 plants, which concentrate CO2 within their leaves to approx 1000ppm, have little or no photorespiration (and increased temperture optima).
Radical Rodent
My apologies. When you stick it out and waggle it like that, the impulse to pull your leg become irresistible. :-)
Returning to Dung's Minoan Warm Period. I did not reject tty's paper lightly.
If I based a major claim on a single datum point in a known noisy and unreliable dataset you would reject it, and you would be right. That is what I did here.
Please dont wave the "it was once warmer, so it will be all right when it warms again" straw man at me. If we transitioned instantly to the conditions you referred to, some 2 million years ago, most of our population, most of our agricultural land and most of our infrastructure would be underwater.
Rather ironic for EM to try all these little scaremongerings, when the species has shown time and again an enormous and increasing level of resiliency despite the world being so hostile to it. We've occupied the whole planet and apart from a large asteroid there's no chance of anything approaching extinction level for Homo Sapiens. Adaptation is our strongest weapon.
As it happens humanity has survived giant volcanoes and several ice ages, with wildly different sea level conditions already.
Mike Jackson
To address your points, if not your sarcastic tone.
"Plants adapt."
Over evolutionary timescales, perhaps. In natural ecosystems over timescales relevant to our discussion they die out and are replaced by another species more tolerant to the new conditions.
If the plant in question is a crop, you change crops. Crop breeding and GM can only produce small changes.
"that the temperature increase is going to be outwith anything mankind has adapted to before;"
This looks probable.
Holocene peak temperatures plateaued at anomaly 0.4C +/- 0.2C 10,000 years ago. held roughly constant to 5,000 years ago and then declined, bottoming out at -0.4C +/-0.1 in 1910.
In lay terms, our entire lifetime as a civilisation is unlikely to have experienced global temperatures outside the range13.5C and 14.6C. Hadcrut4 shows an increasing trend with 2010 and 2014 sharing the current maxima of 14.56C.
Even by Hadcrut4's rather conservative standards we are bumping up against the upper limit of our past experience.
"Ice age in 10 years"
Against a background of increasing temperatures that does not look credible. "Some" may say it, but I see no evidence.
" there is this assumption that nothing good can come of a couple of degrees of warming when the whole history of mankind says you're wrong."
As a world civilisation our whole existence has been under constant or declining global temperatures (as I discussed above). Regionally out record of surviving climate change is poor. Research the Mycenian Greeks, the Mayans, the Chaco Canyon culture, Angkor Wot or read Jared Diamond's book "Collapse".
We have NO experience of surviving as a hi-tech civilisation under long term warming conditions, and our past form is poor. Current attempts to adapt or mitigate lag a long way behind the problems. Post your bets. :-(
Omnologos
I gave a partial answer to you complaint in my answer to Mike Jackson.
I agree that as a species we are now very difficult to wipe out. Hunter/ gathering or subsistence farming are successful default options under most conditions. As small groups we adapt well.
The problem comes when we go beyond subsistence and build civilisations. These tend to last a few centuries, then fail to adapt and collapse when conditions change. Each of those past collapses was probably preceded by someone like yourself, convinced that everything would be fine.
Sorry, EM, but it's still flannel.
You need to define the "problem". We have no experience of surviving as a hi-tech civilisation under any conditions because we have only recently become hi-tech so you don't really know any better than the rest of us.
You challenge the evidence that previous warm periods were warmer than now and you may be right but just as you reject what you call a single, known-to-be-unreliable data set so I reject a single, dubious data set called Hadcrut 4 which was used ( inter alia) to "prove" that 2014 was the hottest year in record, provided you believe that it is possible to measure temperature to hundredths of a degree, provided you ignore the error bars, and provided you ignore the fact that the headlines and the PR and the spin were subsequently revised to "there was a 38% chance that 2014 was the hottest year on record".
Which is all getting us nowhere — including you.
And you bury under all this flannel the fact that temperatures are not doing what they are told by the Climateers but are following what appears to be a fairly well-established and moderately well-understood pattern which has got a lot to do with ocean currents and the sun and feck all to do with CO2, much as the eco-activists are desperate to make ius believe that it has.
I'll follow up your suggested reading list but since Wikipedia suggests no fewer than 88 different hypotheses for the collapse of the Mayans forgive me if I don't (as apparently you do) jump to the conclusion that it was all to do with global warming.
From my relatively limited (and just about as ancient) study of Ancient Greece the decay of the Mycenians was largely due to invasion (Dorian, if I remember) probably compounded by internal unrest.
The idea that this collapse was also due to climate change is of very recent origin. Why does that not surprise me?
Don't Keiller
Alas, all I have is 1970s undergraduate plant physiology and what I've picked up since staying current to teach A Level.
Regarding crops, how do I square your assertion that crop yields will increase wit papers such as Asseng et al(2014) who are expecting crop yields to decrease.
Regarding C4 plants, perhaps I am obsolete, but I was taught that RuBisCo evolved repeatedly as a response to drought, high temperature photorespiration and low CO2.. If photo respiration is a large enough handicap to drive the evolution of a whole new CO2 fixation pathway, why do you give it such a low priority? Since most full C4 plants are tropical and the tropics are warming more slowly than temperate latitudes, this may be peripheral to our discussion.
Mike Jackson
God spare me from people who attack datasets without knowing enough statistics to do so properly. What is your quantitative estimate of the uncertainty in Hadcrut4 and how did you calculate it?
The Mycenians successfully defeated Troy, collapsed into dissenting factions and then weakened rapidly to the point where they were easily conquered by their neighbours. Sounds like another stressed society. On the more general topic of climatic effects on societies you might find this interesting.
"Regarding C4 plants, perhaps I am obsolete, but I was taught that RuBisCo evolved repeatedly as a response to drought, high temperature photorespiration and low CO2"
Obsolete indeed and completely wrong.
RUBISCO evolved some 3.5 BILLION years ago, under conditions of very high (>10% that is 100,000 ppm) CO2. Under such conditions it didn't matter that RUBISCO had the potential to act as an oxygenase. Even when CO2 levels fell to 1000ppm, some 30 million years ago, it still wasn't much of an issue.
It really only became an issue in the current cycle of Ice-ages where low CO2 (caused by cold oceans absorbing atmospheric CO2), combined with high temperatures (in the Tropics, which were largely unaffected) caused massive photorespiratory losses.
C4 photosynthesis evolved repeatedly, as a CO2 concentrating mechanism to counter this.
Two take-home lessons;
1) High CO2 is good for plants
2) Stick to teaching what you know- which, hopefully, is not plant physiology.
You can read all about it in this review;
http://research.eeescience.utoledo.edu/lees/papers_pdf/Sage_2004_NewPhyt.pdf
I remember at the times of usenet some crazy guy who kept predicting the collapse of the Dow. Eventually 2008 did happen, however it'd be hard to use that as evidence that the doomster was right. Analogously for the unending stream of climate gloom. Vague pessimism is of no practical use.
As for resilience, our history is unbroken now for around 56 centuries. That is, somebody somewhere has been using writing every single year for the whowhole of that time, including several volcanic eruptions and a series of differing global climate sets. More, the norm has been that a civilisation has replaced another, often borrowing from the previous one: lost cultures such as the one of the Indus valley are very few.
In this respect, humans have never lost their ways, at a planetary level. Rome may have collapsed for the Romans, but it was a great time to be a Barbarian.
This means the onus on the doomsayers is almost impossible to bear. Scenarios of collapsed global civilisation are close to implausibility, asteroid aside.
There's also the not simple matter that the same dreamy words about a nice and gentle climate coming to an end, have been used 40 years ago alongside predictions of global cooling. This makes those words look like empty rhetoric.
None knows the future. Why is that so difficult to admit.
Don Keiller
Probabably a good idea. :-)
By the way, if you want to incorporate a website address into text as a link use this format
You say that global temperatures have more-or-less flat-lined for 10,000 years until recently; that goes against all the information I have seen to date (though none of the sources will be acceptable you, so I will not bother looking them up again).
As for your assertion that high temperatures AND high CO2 is a death-knell for plants, perhaps you should inform greenhouse farmers about this, as they do insist on growing their plants in temperatures deliberately “forced” upwards, in CO2 concentrations that the present rate of CO2 rise will take the atmosphere several millennia to achieve. Do you ever wonder why you cannot get anyone to agree with you?
is entropic man the same guy as psychotic man?
Radical Rodent the " background of rising temperatures" is the one in the outdated/inaccurate textbooks, that are used in our modern underfunded education system. This is a great excuse to carry on preaching yesterdays failed theories to tomorrow's future.
Radical Rodent
Courtesy of Woodforthetrees, these are the Gistemp monthly global surface temperature figures since 1970.
I have added the linear trend and its 95% confidence limits.
As I said to hunter, I am finding it difficult to see any pause, let alone a cooling trend. Perhaps you could explain how I might see them in this data
Why limit yourself to just 45 years? Why not take it further back? Over 100 years: ooh, look – it is upwards! Good! However, if you start 1,000 years ago, you will find the line is downwards; 2,000 years, and it is still downwards. 6,000 years? Take a guess.
However, all this is from sources you will hold no truck with, so any further discussion does seem rather pointless. I do hope the rise continues at the rate it has been over the last hundred years; I fear that it might not, and will cool – then, there will be problems.
The trouble is, EM, you cannot see the wood for the trees. Take an upper floor of a building; how far from the top step are you? Is the floor between you and that top step level? Or is it a continuous slope upwards from the bottom step? If the building is in total darkness except for where you have trodden, how far away is the next flight of stairs? And are they up, or down?
Take the present temperature records that we have. How far are we from when the temperatures stopped rising (as agreed by NASA, IPCC, UKMO et al – swallow your pride and accept their pronouncements)? Is that a sign that temperatures have levelled out? Of course not (using your logic); we have to look further. For how long were the temperatures rising prior to levelling out? Most records agree that it was a little under thirty years. So, what was it doing prior to that? Well, it would seem that it had been falling for a little over 30 years, and so much so that there were fears of us descending into another ice age. Phew! Thank goodness for CO2 and its warming, eh?
All that is utter balderdash, but it does show that you cannot tell the future merely by extrapolating a very, very small amount of data from such a chaotic system that is the Earth’s atmosphere.
To take the wood for trees analogy further: a wood is planted with three distinct sections – a large section that is all pine; a small section of mixed oak and pine; a large section that is all oak. Using your logic, you will never be in woodland that is all oak or all pine; you will always be in woodland that is mixed oak and pine, no matter how small the mixed oak and pine section is.
Together with the 97%, the way one talks about the "pause" is a clear-cut sign for honesty. Because it is about definitions and accepting reality as it is.
Quick summary:
1. Is there now a pause in the multidecadal globally-averaged temperature rising for the last 150 years? No
2. Is there now a pause in the rising of global temperature in the last 18-20 years ? Yes
3. Does the pause at item 2 mean anything regarding the warming at item 1? Not yet
Alarmists are afraid of 3 so will fight tooth and claw against even admitting 2. This shows how anti-scientific alarmism is, since there is a long list of perfectly good scientists who have spent time to analyse the pause that alarmists cannot possibly recognise the existence of, at least in public.
I hope EM will show some honesty now. The 1970 graph seems otherwise.
ps the pause debate could and should raise alarm bells in the minds of Betts and friends - their topic of study is mangled by alarmism as soon as the alarmists see it fit to distort the science.
IOW scientists, for an alarmist, are just idiotic minions who _have_ to follow the Established Path, or else - cue the L'Aquila threats made by Lew and O(g)reskes.