Desertification, drought, and despair—that's what global warming has in store for much of Africa. Or so we hear.
Emerging evidence is painting a very different scenario, one in which rising temperatures could benefit millions of Africans in the driest parts of the continent.
Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.
If sustained, these rains could revitalize drought-ravaged regions, reclaiming them for farming communities.
This desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a lush savanna some 12,000 years ago.
Green Shoots
The green shoots of recovery are showing up on satellite images of regions including the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers).
Images taken between 1982 and 2002 revealed extensive regreening throughout the Sahel, according to a new study in the journal Biogeosciences.
The study suggests huge increases in vegetation in areas including central Chad and western Sudan.
The transition may be occurring because hotter air has more capacity to hold moisture, which in turn creates more rain, said Martin Claussen of the Max Planck Institute for Meteorology in Hamburg, Germany, who was not involved in the new study.
"The water-holding capacity of the air is the main driving force," Claussen said.
(See a map of global warming's impacts.)
Not a Single Scorpion
While satellite images can't distinguish temporary plants like grasses that come and go with the rains, ground surveys suggest recent vegetation change is firmly rooted.
In the eastern Sahara area of southwestern Egypt and northern Sudan, new trees—such as acacias—are flourishing, according to Stefan Kröpelin, a climate scientist at the University of Cologne's Africa Research Unit in Germany.
"Shrubs are coming up and growing into big shrubs. This is completely different from having a bit more tiny grass," said Kröpelin, who has studied the region for two decades.
In 2008 Kröpelin—not involved in the new satellite research—visited Western Sahara, a disputed territory controlled by Morocco.
"The nomads there told me there was never as much rainfall as in the past few years," Kröpelin said. "They have never seen so much grazing land."
"Before, there was not a single scorpion, not a single blade of grass," he said.
"Now you have people grazing their camels in areas which may not have been used for hundreds or even thousands of years. You see birds, ostriches, gazelles coming back, even sorts of amphibians coming back," he said.
"The trend has continued for more than 20 years. It is indisputable."
The article goes on to say that half of the climate models predict the wetter environment while the other half predict a dryer environment there. Glad that is settled.
At least now the evidence is in which shows that millions of Africans will suffer if "climate change" is halted. Wait. Climate change is already halted and has been for over a decade now. (Unexpectedly, and unmodeled of course). So maybe, just maybe, the continuing greening of North Africa is a phenomenon which is - can it be said? - independent of global climate change or AGW or whatever its nom du jour might be.
At a minimum, this large regional greening represents carbon sequestration that is not likely included in the doomsday models. One might well wonder what other unanticipated effects will be found, if one actually looks.
9 comments:
The concern is primarily with the expense associated with large shifts in population. The Sahara might very well become wetter, at the expense of some other regions which will become drier. Some of these regions support millions of people, and if they have to shift location relatively quickly, it is predicted to be a logistical nightmare and much more expensive than encouraging the development of cleaner technologies now instead of later.
"Climate change is already halted and has been for over a decade now. (Unexpectedly, and unmodeled of course)."
Climate is defined by the WMO as at least 30 years of averaged weather, and preferably 50. Anything less than that is noise. The models are not intended to be that fine-grained, and will not capture year-to-year and even decadal fluctations.
Besides, AGW rests on the presence of a cause, whether the effect is noticeable yet or not.
Consider a cause/effect relationship: X causes Y.
AGW does not look at effect Y and try to horseshoe cause X into it. AGW instead builds a large amount of evidence for the present existence of cause X, whether effect Y has shown up yet or not.
Martin,
You certainly know my position on AGW science and why I am so critical of it, primarily for the political and economic damage that it can do whether it is right or wrong. But I have to disagree with your X / Y analog, and here’s the reason why in 20,000 words or less. Or more. We’ll see.
Traditional empirical science depends on cause AND effect, and also requires replication and non-falsification of that relationship. Also it is typically sequenced by first observing effects inductively, forming an hypothesis or rule, and then projecting from the rule deductively, devising methods of causing the effects for observation and non-falsification. So going straight to cause without observable effects falls outside this realm.
I don’t think that AGW science ignores Y at all. Y is based on purported temperature observations and tree rings as well as glacier and sea bed readings, etc. But that is all historical (forensic). Y is not observed real time.
X is based on CO2 history projections, and AGW (the conclusion) is based on computer models which attempt to connect X to Y and which are of unknown predictive value, with that fault being excused by the granularity issue and noise volume (meaning that other major factors are swamping out the effect).
Where this pursuit fails the standards of science is in its inability to directly relate the effect immediately and specifically to the cause to which scientists wish to attribute the guilt / responsibility. Hume would have apoplexy. Should there be an actual direct and mathematical relationship between excessive heat retained on earth and excessive CO2, then there is no obvious reason why the relationship is not relatively quickly observed, certainly not decades. Heat flow happens much more quickly, as going through the four seasons attests. So time delays of decades or half centuries seems out of bounds, even if the intent is to average out noise. The term "noise" is deceptive because it refers to other valid responses to other causes which are congruent with the AGW /CO2 issue, and which are large enough to swamp out AGW / CO2.
Further, the inability to create and test the actual effect as produced by the proposed cause, plus the short duration of readings that are direct and accurate (if they exist), means that the inferences being drawn are neither deductive nor inductive. That leaves speculative.
If, as you say, X is defined as the cause of Y without empirical standing, then the basis is that AGW is man-made by definition (A = anthropogenic); that CO2 has to be presumed to be the culprit since that’s what man produces irresponsibly and en masse; that warming has to be presumed to be bad in a zero sum sense, therefore a crisis is imminent (and must be prevented or accommodated, politically speaking).
What we have is this:
a) no direct empirical confirmation or attempt to directly falsify the cause / effect relationship;
b) presupposition of a cause;
c) presupposition of primary consequences;
d) presupposition of secondary consequences;
e) a conclusion drawn on this basis;
f) If acted upon, probable global economic and political chaos, all acting on a chain of presuppostions. This is the definition of the Precautionary Principle, which is actually the bane of science in other disciplines.
The only reason that this type of study continues is that it is able to claim disaster and world-wide destruction. The unknowns are so large and many that no other reason could account for its continued funding. No other non-crisis science would survive under these conditions.
I think that this response is actually pro-science, in the sense that integrity is demanded of "scientific" conclusions that are purported to be so immensely important. This is not a condemnation of science, only of those miscreants who deserve it.
"no direct empirical confirmation or attempt to directly falsify the cause / effect relationship"
John Tyndall empirically verified CO2's heat-absorbing abilities in the lab in 1861. (Tyndall 1861)
The rising CO2 levels in the atmosphere are increasing in C12/C13 ratio, an indicator of plant-based CO2 rather than volcanic CO2. If this was not true, it would falsify AGW. (Manning 2006 (PDF))
Satellites are currently measuring more heat coming into the upper atmosphere than is leaving it, at wavelengths that CO2 absorbs. If the satellites measured no such thing, then it would help to falsify AGW. (Harries 2001, Griggs 2004)
Heat at the surface level is increasing at wavelengths assocated with CO2 absorption. If this were not happening, it would be a falsification of AGW. (Philipona 2004, Wang 2009, Evans 2006)
An enhanced greenhouse effect is expected to make the nights warm faster than days. This is happening. If it wasn't, it would help to falsify AGW. (Braganza 2004, Alexander 2006)
Even while atmospheric warming might be flat, the heat budget of the entire climate system including oceans, ice, and land continues to increase. The planet is accumulating heat at a rate of 0.77 Watts/M2. If it wasn't, it would help to falsify AGW. (Murphy 2009)
Since models are intended to predict the future, the only way to evaluate them is how well they can back-predict the past. None of the GCCs can recreate the 20th Century climate without adding in anthropogenic CO2 forcing. (IPCC WGI TAR)
Martin,
I think maybe you missed my main caveat, which was the word “direct” used for both cause and effect.
"no direct empirical confirmation or attempt to directly falsify the cause / effect relationship"
Because of the indirect and second order nature of climate science, it does not satisfy the direct “force and measure” method of analyzing natural cause and effect. Measurement of second order effects and possible epiphenomena are made and then extrapolations are performed.
”John Tyndall empirically verified CO2's heat-absorbing abilities in the lab in 1861. (Tyndall 1861)”
No argument there.
The rising CO2 levels in the atmosphere are increasing in C12/C13 ratio, an indicator of plant-based CO2 rather than volcanic CO2. If this was not true, it would falsify AGW. (Manning 2006 (PDF))”
However, increasing the base of plants also sequesters carbon. This is not a direct relationship and is (imho) probably epiphenomenal to normal heating.
”Satellites are currently measuring more heat coming into the upper atmosphere than is leaving it, at wavelengths that CO2 absorbs. If the satellites measured no such thing, then it would help to falsify AGW. (Harries 2001, Griggs 2004)”
Of course that always happens, otherwise there would not have been a release from the ice age.
”Heat at the surface level is increasing at wavelengths assocated with CO2 absorption. If this were not happening, it would be a falsification of AGW. (Philipona 2004, Wang 2009, Evans 2006)”
Same comment as the previous.
”An enhanced greenhouse effect is expected to make the nights warm faster than days. This is happening. If it wasn't, it would help to falsify AGW. (Braganza 2004, Alexander 2006)”
Maybe you meant “cool more slowly”? Otherwise I don’t know what you mean. Assuming that you do mean “cool more slowly”, then the previous two comments apply.
”Even while atmospheric warming might be flat, the heat budget of the entire climate system including oceans, ice, and land continues to increase. The planet is accumulating heat at a rate of 0.77 Watts/M2. If it wasn't, it would help to falsify AGW. (Murphy 2009)”
First off I doubt this. The rate of solar insolation is variable, so heat accumulation is also variable. Second, heat accumulation has been occurring since the ice age, etc. Perhaps a changing rate of accumulation occurs, but not merely the static rate of accumulation itself. And even a changing rate of accumulation might be explainable without human intervention, as some of the runaway models wanted to predict.
”Since models are intended to predict the future, the only way to evaluate them is how well they can back-predict the past. None of the GCCs can recreate the 20th Century climate without adding in anthropogenic CO2 forcing. (IPCC WGI TAR)”
This is not a direct measurement. And because there is a 30 to 50 year period required for confirmation, there is no proof that the models are correct.
If science is defined by its ability to shed internal error by virtue of replication and falsification, then climate science fails this duty, at least in the period of usefulness to the human race. Results of hypothetical projections that aren’t available even for potential falsification for another half century are not useful as knowledge in my lifetime. Yet easily within my lifetime the Chicken Littles want to redesign the political and economic structure of the world around this non-knowledge. And like it or not, when one uses the term “AGW”, the political and economic issues are firmly attached to it, non-detachable parasites. Perhaps that's not science, but it is reality, and science is an attempt to understand reality... right? I.e. AGW is a cause, and hysteria with global overtones is an effect.
Martin said: The rising CO2 levels in the atmosphere are increasing in C12/C13 ratio, an indicator of plant-based CO2 rather than volcanic CO2. If this was not true, it would falsify AGW. (Manning 2006 (PDF))”
You replied: However, increasing the base of plants also sequesters carbon. This is not a direct relationship and is (imho) probably epiphenomenal to normal heating.
Plant based CO2 in the atmosphere is the result of burning plants. The carbon in the CO2 in your breath is plant based. Burning a tallow candle releases plant based CO2, as does burning fossil fuels. With this in mind when you say: However, increasing the base of plants also sequesters carbon. You are not wrong, it's just (it seems to me though I might be misreading you) that your statement is a non sequitur.
Mmm, yeah I skipped a step there. Increasing CO2 will increase the plant base, which in turn sequesters more carbon... a self-correction of sorts, and not necessarily predictable with any certainty.
Isn't it true that the amount of plant life, including sea and water based plant life, is rapidly decreasing?
Can you see a situation where the amount of carbon released into the atmosphere out-paces the ability of plant life to store it?
As I recall, possibly incorrectly, the models do account for extra greening, with retreating ice caps being replaced by new growth. But there also is new release of CO2 as the tundra decomposes more rapidly.
But there are other variables. The last dairy farm for miles around just went out of business. There are abandoned farms all around which have gone back to "sprouts", which are trees planted by birds and squirrels. A ten year old cedar tree can sequester a lot of carbon. They grow close together and produce more biomass than grass in pastures. The economy is producing more forests this way.
Just this week, the cooling of the last ten years has been attributed to the burning of sulfurous coal by the Chinese, which if true would be an admission that man's affect on the climate can be in the direction of reducing the temperature.
Who knows all the variables and can predict the impact of all the variables including the massive forest fires, the rebound seen in Yellowstone after their fires, the return of the Japanese to coal fired power, etc?
"Just this week, the cooling of the last ten years has been attributed to the burning of sulfurous coal by the Chinese,"
By "cooling", you mean "slowing the upward trend".
If you look at papers from the National Academy of Sciences, sulfur, amongst other materials, has been known to reflect sunlight back into space (not directly but by "whitening clouds") for years. It's not a new discovery.
"if true would be an admission that man's affect on the climate can be in the direction of reducing the temperature."
"Admission"? That mankind's activities could have the effect of change in temperature has been the message for years.
This question still stands: Isn't it true that the amount of plant life, including sea and water based plant life, is rapidly decreasing? Even taking into account abandoned farms and retreating ice caps.
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