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"Africa's deserts are in retreat," according to New Scientist magazine
According to a story on CNN summarizing New Scientist magazine...
Plants fighting back against African desert
An analysis of satellite photographs taken this summer show vegetation is edging out sand dunes in an area ranging from Mauritania to Eritrea in a trend that began in the 1980s.
"Africa's deserts are in retreat," New Scientist magazine said on Wednesday.
Unfortunately the New Scientist website is down at the moment with a message that they are trying to get it back on line 'as soon as possible'. According to the CNN summary, researchers did an aerial survey of the Sahara this summer and then compared he results with a survey done in the 1980s, and have concluded that the desert is retreating. They state that they believe that trend began after the 80s and "has gone largely unnoticed. Only now is the evidence being pieced together," the magazine added.
Greenness April/September 2002
Infrared cloud image for September 18th, 2002
The image for the end of November, 2002 indicates that trend continues...
The images above show the greenness maps for the desert in April of this year, before the rains failed, and the greenness disappeared. Rains began returning with increasing tempo towards the end of July and the map on the right shows both a newly emerging green streak in the western Sahara, where most of the recent rains have been concentrated. As well a comparison of the line of latitude on the two photos from this spring and for today, September 18th, shows that since this spring the vegetation line has climbed rapidly several degrees northward and has met, and even crossed the latitude line on the map crossing the southern sahara. The blue areas are those with extremely healthy vegetation, and so, it would seem, based on my observations, that these changes are actually taking place quite rapidly, and not gradually over decades. It is certainly true that the rains have been exceptional and I have been an avid desert watcher for years, monitoring the desert, the cloud cover, the precipitation and the vegetation and can say that what has been happening is very unusual, that desert having been nothing but a terrible disappointment for years, and now finally its becoming very interesting, with much happening, as all the signs come together to indicate that a climate change is finally taking place. I also took exception to the fact that the scientists stated that change had been taking place 'and no one noticed it'. Certainly the farmers on the savannah would be the first to notice, and last fall it was reported by the FAO that farmers had ventured north into what was previously desert to experiment with planting crops. I never did hear how they did, but it really is impossible for that desert to retreat without the Sahel agriculturists noticing it right away and migrating northword as they reportedly did last fall. As present trends continue it looks, from the maps, that the Sahel will continue to push northwards, as the rains have been building in tempo, and not just on the Sahel but on the Sahara itself, which, this year has been oscillating between desert and vegetation, and now, with the cooler winter on the way I expect to see another surge of vegetation and increased precipitation (plants and rain being partners, one reinforcing the other - it has been said that one of the reasons the Sahara has been a desert for so long is that it has no plant life, so it only remains for vegetation to get a better foothold than it apparently had breifly this spring for a cycle of renewal to take firm hold, and the desert to return to life.)
In any case, it has been a very interesting desert this year and not the same disappointing thing it has always been in years past...
Changing climate on the Sahara brings floods
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