“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.”
The study, which is scheduled for publication Friday, Dec. 16, in the Journal of Arid Environments, was based upon climate change records, aerial photos dating back to 1954, recent satellite images and old-fashioned footwork that included counting and measuring over 1,500 trees in the field. The researchers focused on six countries in the Sahel, from Senegal in West Africa to Chad in Central Africa, at sites where the average temperature warmed up by 0.8 degrees Celsius and rainfall fell as much as 48 percent.
They found that one in six trees died between 1954 and 2002. In addition, one in five tree species disappeared locally, and indigenous fruit and timber trees that require more moisture took the biggest hit. Hotter, drier conditions dominated population and soil factors in explaining tree mortality, the authors found. Their results indicate that climate change is shifting vegetation zones south toward moister areas.
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  IMAGE:Rainfall in the African Sahel declined more than anywhere else in the world in the period of recorded measurements, causing increased aridity, as evidenced by this dust storm in Senegal.Click here for more information. |
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“In the western U.S., climate change is leading to tree mortality by increasing the vulnerability of trees to bark beetles,” said Gonzalez, who is now the climate change scientist for the National Park Service. “In the Sahel, drying out of the soil directly kills trees. Tree dieback is occurring at the biome level. It’s not just one species that is dying; whole groups of species are dying out.”
The new findings put solid numbers behind the anecdotal observation of the decline of tree species in the Sahel.
“People in the Sahel depend upon trees for their survival,” said Gonzalez. “Trees provide people with food, firewood, building materials and medicine. We in the U.S. and other industrialized nations have it in our power, with current technologies and practices, to avert more drastic impacts around the world by reducing our greenhouse gas emissions. Our local actions can have global consequences.”
Other co-authors of the study are Compton J. Tucker, senior earth scientist at NASA’s Goddard Space Flight Center, and Hamady Sy, country representative for Mauritania at the Famine Early Warning Systems Network.
Funding from NASA and the U.S. Geological Survey helped support this research.
Just what does this have to do with NASA? Someone needs to get NASA back on topic.
If this has been going on since the 50’s, Al Gore’s Warming can’t be to blame. /sarc
On a less humorous note, I wonder if they studied the actual cause, such as a shifting weather pattern, the tropical jet stream or anything else not man created.
Oh my. I’m sure this has never happened anyplace in earth’s ancient past.
Don’t have a problem with people noticing that the climate is getting drier in some places, causing some trees to die.
The unanswered question is – “Is this caused by AGW?”
I’d be interested in knowing about the impact of regional deforestation, grazing patterns for livestock, diversion of waterways (as in China), application or withholding of pesticides and/or other chemicals (or fertilizers for that matter). Moreover, in the scheme of things, considering the age of the Earth, I’d like to see projections on rainfall patterns for longer than the data provides.
I’m not skeptical about science, but I am eternally skeptical about political science.
The last time that I checked, using a tree as firewood killed, looking out window at two stumps right now!
“Journal of Arid Environments.”
This itself is the problem; Make-work journals to serve the interests of a few whacko paper writers whose alarmist “findings” are needed to keep them and their funding going.
It’s amazing how you can arrive at the answer you want by closely picking the start-end dates of your study. Quoting from a 2008 article at The Encyclopedia of Earth, “The Greening of the Sahel” (here):
NASA provides satellite pics that the Warmies can Interpret to show Climate Change is the culprit. Any Body that supplies funding to warmies, is an ally,and they like to give them creds.
They think the Sahal is in trouble? Hell, the North Pole is melting,and Santa is losing his home. Don’t believe it? Google David Suzuki Foundation Christmas ad. Scared the heck out of kids, when it was shown. He was seeking donations for his Climate Change Foundation.
What a SCUMBAG this guy is. He is a Geneticist masquerading as a Climatologist[I believe he took a couple of courses on climate science to make himself an “EXPERT”]
My sentiments echo others. Why is is just presumed that this is caused by man emissions of a trace gas into the atmosphere? Did they start looking at trees with that prejudgement in position already, sounds to me as if that is precisely did!
Just a few thousand years ago the whole of Sahara, where wind now blows about sand dunes for hundreds of miles, has been covered with grass and trees, supporting innumerable herds of grazing animals, giraffes, elephants, monkeys, and predators.
Yes, climate has changed, and continues changing. Earth’s axis of rotation changes its angle, the Sun is never constant, volcanoes cover the skies with ash, cosmic rays create more or less clouds as Solar wind oscillates, and as Solar system flies through different regions of space. Not to mention “unknown unknowns” of biological and astrophysical nature.
It may be that overpopulation and excessive agricultural activity in Sahel countries contribute to the natural change somewhat (how much? how little? who is to say? alarmists interested in getting grants?) — but it should be obvious even to a visiting scholar in Berkeley that the largest desert in the world is not a human creation.
“People in the Sahel depend upon trees for their survival,” said Gonzalez. “Trees provide people with food, firewood, building materials and medicine.
Firewood, do they replant after felling? after all it is well known that trees make clouds which make rain. There has been a similar problem with the Snows of Kilimanjaro after all.
“In the western U.S., climate change is leading to tree mortality by increasing the vulnerability of trees to bark beetles,” said Gonzalez, who is now the climate change scientist for the National Park Service.
Utter crap. We need weeks of -20°F to kill off the beetles. How often has that happened. Not in the 40+ years I’ve been in Colorado.
http://www.eoearth.org/article/Greening_of_the_Sahel
http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html
The Sahel has been drying for hundreds, perhaps thousands of years. This article is a monument to ignorance.
I thought it had been known for decades that the region concerned was susceptible to the Sahara shifting cyclically poleward and then equatorward.
Latitudinally shifting climate zones moving in response to combined solar and oceanic variations is clearly the cause.
The impression I had was that severe Sahel droughts occurred during the mid 20th century cooling spell and then there was some greening of the area during the late 20th century warmup and now drying again as the troposphere starts to cool once more.
Entirely consistent with routine shifting of the permanent climate zones in response to natural solar and oceanic forcing.
Just like everything else then 🙂
http://rs.resalliance.org/2005/11/14/the-greening-of-sahel-passive-recovery-or-active-adaptation/
This study is a pile of garbage. Logging could easily explain the disappearance of the trees but then that wouldn’t fit into the ideologically driven story that burning fossil fuels is destroying the planet. The Climate Liars attribute everything to Co2. I wonder if we can blame their lies and corruption on excess Co2 in the atmosphere.
[ written as he was flying over the Sahara, emphasis mine ]
_______________________
“It is remarkable to think that these treeless desert lands were, half a million years ago, humid tropical forest lands, with now-extinct primates and a rich diversity of plants and animals— a far cry from the impoverished biota that populates the interior of northwestern Africa today.
If the reader is wondering what happened to the rainforest, the unsurprising answer is… global climate change. It is not a new phenomenon: climate change is the rule, not the exception. And climate change was the rule long before humankind came to dominate our earth or to infuse our atmosphere with greenhouse gases. Climate change, extinction, and speciation have been acting in concert for many millenia. Past climate changes in the climate of northern Africa certainly caused local extinction pulses. These have been well documented by paleontologist Scott Wing, who has written of the Koobi Fora flora and fauna— a now vanished humid tropical world in northern Africa.”
Bruce M. Beehler, Ph.D.
“Lost Worlds: Adventures In The Tropical Rainforest”
p. 201
Yale University Press
New Haven, 2008
( Dr. Beehler is vice-president of Conservation International and a leading authority on birds of paradise )
“People in the Sahel depend upon trees for their survival,” said Gonzalez. “Trees provide people with food, firewood, building materials and medicine. We in the U.S. and other industrialized nations have it in our power, with current technologies and practices, to avert more drastic impacts around the world by reducing our greenhouse gas emissions. Our local actions can have global consequences.”
They, these so called scientists, seemingly cannot resist the issuing of speculative and overtly political statements in conjunction with their research papers. Does Gonzalez’s professional knowledge extend to expertise on “current technologies and practices” such that he can speak with authority on control or limitation of greenhouse gas emissions? Why can they not just present their work in an unbiased and professional manner? Is it too much to expect them to shut up about issues where they lack expertise? At least they should qualify their opinions on matters outside their expertise as personal and not professional.
Ten years ago I remember reading articles on how green the Sahel was getting. Now that we are cooling off, guess what?
Apparently modern AGW is retroactive… The drought that caused the rapid collapse of the Egyptian empire would not have happened without our influence? According to recent findings that show the cause of the annual flooding of the Nile region was seasonal rains in a neighboring region, which stopped, and resulted in mass starvation and the end of the great society.
A widespread 140 year drought about 4,000 years ago, called the First Intermediate Period … couldn’t happen today? It could only happen as a result of AGW?
Pushing the start date of the timeline back a little shows a totally different regional climate picture.
My cat died due to climate change.
No proof. Just sayin’.
They get away with this crap bs science every day! Garbage!
My cat did die but she was 22 years old…
How old was that tree?
Just askin’.
One factor in the changes in North Africa which was the breadbasket of the Roman Empire may well have been the introduction of large numbers of goats whose browsing is well known to have an adverse effect on trees. So the global warming is man-made after all! Bloody goatherds…
Thanks, Juraj V. for the links to articles on the “greening” of the Sahel. That was the last thing that I recall reading about it, and those articles were published in 2008 and 2009. An illustration of the great difficulty that part-time readers of climate science (like me) have difficulty with. This should be easy enough to differentiate though – is it greening or not?