Guest Post by Willis Eschenbach
The Sahel, that stretch of harsh territory south of the Sahara desert, is a bleak region. I did some work there, in a couple three countries. I came away with the conviction that if every day, every person in the Sahel planted one fruit tree and killed one goat, in about twenty years it would be worth visiting.
Figure 1. Map of the Sahel region, shown in orange.
Anthony highlighted some science by press release in “Climate change blamed for dead trees in Africa“. The press release is about a paper that won’t be published until this coming Friday. The lead author provided the following quotes for the press release. (emphasis mine)
“Rainfall in the Sahel has dropped 20-30 percent in the 20th century, the world’s most severe long-term drought since measurements from rainfall gauges began in the mid-1800s,” said study lead author Patrick Gonzalez, who conducted the study while he was a visiting scholar at UC Berkeley’s Center for Forestry. “Previous research already established climate change as the primary cause of the drought, which has overwhelmed the resilience of the trees.”
I thought, “Really”? Because I was sure I remembered all kinds of recent articles about the “greening of the Sahel”. In any case, I’ll take any excuse to learn something new. So I went off to see what the rainfall records had to say about the “world’s most severe long-term drought”.
I found three rainfall records that covered the Sahel in the time period from 1901 to the present. Two (CRU and GPCC) are available from KNMI Climate Explorer, and one (Sahel Index) can be downloaded from the University of Washington. I used the same geographical area as used by the University of Washington, from 10-20°N, and from 10°W to 20°E. The results are shown in Figure 2.
Figure 2. Three different estimates of rainfall in the Sahel region, 10-20°N, 10°W-20°E. Bright red line shows the 9 year Gaussian average of the median of the three estimates. Photo is of the Sahel region, Senegal
I’m sorry, but I’m not seeing either a “severe long-term drought”, or a drop of “20-30 percent in the 20th century”, or a human fingerprint in that record. Modern times are drier than mid-20th century, but not much different from the first part of the century. Rainfall has gone up, and it has gone down, and then back up again. Nor is there any obvious correlation with the general warming of the planet over the same time period. Given the close agreement of the three records, I think we can have reasonable confidence in the data.
I did enjoy his claim that “Previous research already established climate change as the primary cause of the drought.” Climate change causes droughts? Interesting theory. Does climate change also cause not-droughts? I wonder what else is caused by climate change, given that the climate has always been changing.
Finally, I was not mistaken that I remembered articles about the “greening of the Sahel”. Here’s information from the Encyclopedia of the Earth, from National Geographic, and from the Global Warming Policy Foundation regarding how the Sahel has been getting, not drier and browner, but wetter and greener ever since the 1980s.
Conclusions? My only conclusion is that folks are getting desperate for funding, and that the manufacturing of climate pseudo-catastrophes is a booming cottage industry.
w.
PS—I’m dead serious about planting trees and killing goats. The main cause of what desertification occurs in the Sahel is humans, but not by way of CO2. We do it by burning whatever will burn to cook our food, and by letting the goats destroy the rest.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Don’t forget donkeys — they are vegetation destroyers in Southern Africa. They cannot climb like goats, but they can uproot plants and completely destory them.
Overherding is the major factor. Numbers of animals constitute the measure of wealth, not the health of the animals. Consequently there are usually far too many skinny animals grazing per unit area.
While goats and sheep are very effective at killing by eating seedling trees, they don’t generally kill mature trees.
If mature trees are dying as this study says then the likely reason is a lowered watertable which tree roots can no longer reach. Which indicates misguided damming and irrigation practices as mentioned in earlier comments.
RGB, thanks for your effort in answering Garretts claims in such a detail. The only mistake you made concerns the Nobel Peace Prize, it was not awarded to the IPCC Hockey Team on the basis of scientific achievements, it could not since the Nobel Committee consists of Norwegian retired politician with no scientific compentence to review any science. It was based on the political achievements of the IPCC hockey team. In fact, the Hockey Team members that use the Nobel Peace Prize as some kind of cerificate for the quality of their science are only able to show their own vanity for publicity.
Traveling across unpopulated areas of the Sahel (where I did some work back in the 1970s), you could see a lot of scrub growth. But when the shrubbery disappeared, you knew you were within a few kilometers of a settlement…and in range of the grazing goats. Solution to desertification: eat more goats!
Best clue to the cluelessness of the report: “since measurements from rainfall gauges began in the mid-1800s” So the most recent 100 years are the worst in 150 years…statistically meaningless.
rukidding says:
December 13, 2011 at 2:00 am
What’s the latitude there? The Shahel gets a heck of a lot of sun, that’s gotta lead to a lot of evaporation and transpiration.
I haven’t seen the paper but when reading the press release quotes, I took it to mean that the rainfall for the entire 20th century was down 20-30%, compared to the last half of the 19th century. It does appear that the GPCC record was much higher preceding 1900 (the dashed line in the original chart.) Are the 19th century data available somewhere?
Also, I would guess that by saying “Climate Change” the author was implying “caused by AGW” but I don’t see that in the abstract. However, it’s not surprising that a change in the climate affects the environment. It’s been happening for billions of years now and it’s not news that it’s still occurring.
Garrett, have /you/ analysed any Sahel precipitation data? The abstract of the paper, which is available on line, though the article itself sits behind a paywall of about $31, makes no direct mention of any time series analysis, or any reference that might be accessed if one wished to make an independent assessment of what has been observed. No doubt you have read the paper carefully. How else could you be so sure about its full content. Perhaps you could verify for us that the actual primary data have been archived, and if so where they may be found. I would be delighted to look really closely at the relevant time series.
Robin
Overuse of firewood is because the do-gooders do not want them to have electricity, and the too-many-goats problem is because of lack of roads and banks. Without a bank, the only way to store your wealth is as livestock so you keep lots of them.
Willis,
The IPCC 2007 WG I report does not indicate any pronounced future drying of the
Sahel band, rather the opposite. The precipitation loss, based on regional models
is projected to occur more to the North, e.g the Mediterranean coast area.
I think the most important insight of Willis is in the third to last paragraph, and can be summarized in the seemingly paradoxical statement that climate change is a constant.
Constants cannot explain variance. Period.
A couple decades ago, churches were sending farm animals all around the globe to local poor families in need of a cottage industry. What kind of animals you ask? Americun of course. Those goats just might be the ones we sent.
Satellite images show very dramatic impact of grazing on one side of a fence and not on the other. E.g. see ranches.
I’ll second Willis’ observation on goats.
From 2005:
Global warming could end Sahara droughts, says study
http://www.guardian.co.uk/science/2005/sep/16/highereducation.climatechange
quote:
Writing in the journal Geophysical Research Letters, the scientists say the increased rainfall could “strongly reduce the probability of prolonged droughts”.
Reindert Haarsma, who led the research, said: “We were surprised that it was such a big rainfall signal. There is a lot of uncertainty in this kind of prediction but it is possible the Sahara region could benefit from climate change.”
—
So … no matter how the climate changes (more rain / less rain) there are climate models that predict it and thus the change will confirm “climate change” (formerly known as global warming).
Willis, I don’t know if I told you yet. I think I have discovered a correlation between the leaf area index (LAI) and the entrapment of heat (warming). You will get this if you carefully study my tables here.
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
However, to be able to put a figure to that correlation I need to actually get the actual LAI figure at the places where I measured.
Is there anyone here who can help me to get the actual figures of the LAI that is being talked about here:
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
?
eeeehhhh
I generally agree with Willis but I have to disagree somewhat with him this time. The average rainfaill from 1900-1950 appears to be about 470mm while from 1950-2010 it is closer to 410, a drop of almost 20%. Hoiwever, if you analyze the trends a little more closely you see that dropoff in rainfaill happened from 1950 to the 1970s, when the earth was supposedly headed for an ice age. From the 1980s up ithe rainfaill has been increasing as the worst part of AGW was supposedly occurring.
I liked this the excerpt from the “Global Warming Policy” document referenced in the article.
“However, the greening cannot be explained solely by the increase in rainfall. There were vegetation increases in areas where rainfall was decreasing, suggesting another factor was responsible for the greening in these areas. This other factor might have been the rise of atmospheric CO2 levels. The aerial fertilization effect of the ongoing rise in the air’s CO2 concentration increases greatly the productivity of plants. The more CO2 there is in the air, the better plants grow. Rising atmospheric CO2 levels also have an anti-transpiration effect, which enhances the water-use efficiency of plants and enables them to grow in areas that were once too dry for them.”
Willis,
you figured out the GOAT problem and valuable info was added by the goat keeper Caleb, and then also by Frosty and Hexe Froschbein…..Well, goats are wonderful, pleasant, cute ….animals… I live here in Spain, bought a plot of land, which is under nature protection (no HUMAN action permitted), rainfall as in the Sahel of 400 mm/year, now I will get a contractor in with goats and they will clear my plot NATURALLY from all those heather/rosmarin and “mata”-shrubs….
These animals are a MENACE to nature, ripping the plants out with the roots….GREAT!….
GOATS belong to the steep mountains, where they survive on ripping out moss….
They do not belong into the flatlands where they damage indigenous nature (which includes insects, smaller and larger animals, which live in symbiose with regional plants…), GOATS do not belong into the Sahel zone….., now other alternatives: As in the Bible: the true
FLATLAND animals are SHEEP…..
Lamb stew and sheep cheese are very delicious…. The Bible says: ….”and then they sacrifized a LAMB to welcome the guests…..Why not stick with the old tradition? And continue with animals of the high mountains, which harm the Sahel….?
What is neededd for Africa is as Willis says, get one goat off a day…… but now: BRING one sheep in a day… the sheep respect the plants and the roots but nibble on the tops…….
Willis,
ca. 515 (max 9 yr avg.) to ca. 410 mm/yr (2009) is ca. 25% so cherrypickingly, they’re right, 20 to 30%.
Garrett says:
December 13, 2011 at 2:35 am
LOL. That abstract is priceless. They site two rainfall studies. One is for the period 1950-1980, so….. not so much “long term”. The other is much longer term! 1900-2100!! Yep. They predicted the future with their models, so this paper can use it as “facts”. “Peer review” is a joke in climate science.
As for the rainfall chart in this article, the period from 1970 to 1990 would be a real tear jerker if you had a farm in the Sahel. In just a few years, the rainfall went from 500mm a year to less than 300mm a year. A dry land farmer in West Texas would not be able to grow anything in that time frame. The plant distribution would shift from from a grassland to a desert sagebrush. Most grasses, trees in the wetter canyons and bushes in other areas would die. This is significant.
So, I think the conclusion that the Sahel was in a long term drought is true and its also true that while it is getting wetter, its nothing like the turn of the century when there were some very wet years. They are critical for groundwater recharge. It is also true that the Sahel has been much wetter in the past and much drier.
I’d agree with Willis that overgrazing is the most pressing issue in most subsistence grassland societies with respect to maintaining biological productivity. The trees and grasses that might have survived a drought or two are eaten by the goats and their reserves are exhausted and they die. The plants also help with the water cycle in that they put moisture into the air and keep the ground cool and slow runoff.
In reading the various articles on the internet, the Sahel is entirely dependent on monsoon flow and the ITCZ. Which are entirely dependent on global weather patterns.
Another wonderful deconstruction !!!!
Great job Willis.
There have been many recorded periods of drought in the Sahel, and there is nothing to suggest the drought of the 60’s into the early 90’s was in any way unusual. Recent studies in 2006 and 2009 suggests a leading role is played by the AMO. From wikipedia: A 2006 study by NOAA scientists Rong Zhang and Thomas L. Delworth suggests that the Atlantic Multidecadal Oscillation plays a leading role. An AMO warm phase strengthens the summer rainfall over Sahel, while a cold phase reduces it.[29] The AMO entered a warm phase in 1995 and, assuming a 70-year cycle (following peaks in ≈1880 and ≈1950), will peak around 2020.[30]
A 2009 study by Shanahan et al. found further evidence for a link between the AMO and West African drought.[31]
Assuming this is true, we can expect the recent greening of the Sahel to continue for another decade or so.
This “study” of Gonzalez’ is nothing more than one more pathetically desperate and
fraudulent attempt by government-funded “scientists” to link “manmade climate change” with naturally-occurring climatic events.
@Garrett: As Warmist trolls go, your meager attempts come off as mere arm-flailing. Please try to do better. Thanks.
“While goats and sheep are very effective at killing by eating seedling trees, they don’t generally kill mature trees.
If mature trees are dying as this study says then the likely reason is a lowered watertable which tree roots can no longer reach. Which indicates misguided damming and irrigation practices as mentioned in earlier comments.”
Well, as a farmer with experience in this, during droughts, goats will eat the bark off mature trees. Humans will cut off the branches to feed them to the goats. As trees are further stressed, insects will also feast.
I agree about groundwater levels, but where there are goats, it is far worse.
The main cause of what desertification occurs in the Sahel is humans, but not by way of CO2. We do it by burning whatever will burn to cook our food, and by letting the goats destroy the rest.
Willis, may I implore you to be careful with the use of the “we” word? I am not burning Sahel vegetation, and I am not letting or forbidding any goat to do anything. I have no goats.
The climalarmists say I am responsible for global warming using the “we” technique, and say I must personally offer sacrifices to appease the mighty ugly bitch from hell, Gaia.
I’m sure your use was a simple oversight.