Staying on the subject of North Africa, this post concerns the Sahel. Previously known as the Sudan, which is now the name of a country at one end of the Sahel, the other end being the Atlantic Ocean. It is basically grassland. As we noted in the earlier post the Sahara itself was very much like the Sahel for a few thousand years. Is that telling us something? What would have become of the Sahel if the climatic zone had shifted northwards? Would it have been semi tropical?
What is clear is that the Sahel supported herds of animals better known from further south, such as giraffe, elephants, ostrich, crocodiles, and lions and cheetahs etc. These still exist to some extent in southern Sudan as they have a direct link by land to East Africa [Kenya, Tanzania, and Uganda for example]. During the various cooling episodes in the mid to late Holocene, aridity became more and more a problem. Are we again to blame pastoral societies? In fact, it has been pretty arid in the Sahel in the very recent past. At https://thegwpf.com/images/stories/gwpf-reports/mueller-sahel.pdf … which tells us that the Sahel, is curently growing – eating into the desert. Vegetation now exists where not long ago it was absent. Why is the southern Sahara in retreat?
It seems there has been an increase in rainfall since the mid 1980s. However, we are also told the increase in vegetation cannot entirely be attributed to a small increase in rainfall. Some other factor has come into play. Others suggest changes in wind patterns may disperse monsoon rains across the southern boundaries of the desert. Pastoral tribesmen still inhabit the grassland zone – yet it is growing. An article in the journal Nature has upset the applecart by attributing the greening to the increased levels of co2 in the atmosphere. They call it co2 fertiisation – see https://www.nature.com/articles/nclimate3004 … as well as https://doi.org/10.1038/nature11299 … and https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/grl.50563 …
This is also the subject of a post at Science Daily – see https://www.sciencedaily.com/releases/2013/07/130708103521.htm … which begins, increased levels of co2 has boosted green foliage across the arid regions of the world over the past 30 years – through a process known as co2 fertilisation. This research was via satellite observations, and by CSIRO, in collaboration with the Australian National University. Australia itself witnessed an 11 per cent increase in foliage – but it also affected North America, the Middle East, and Africa. So, co2 is not a pollutant. It is clearly beneficial to plants – and therefore, food production. Indeed, market gardeners introduce a high level of co2 into their greenhouses, in order to boost yields. The fact this is rarely mentioned by the doomsters, as they are sometimes referred to, a rather mild derogatory terminology compared with some labels aimed at them, is significant. It actually blows a hole in their argument. Humans are not doomed. Far worse environmental downturns, and upticks, have occurred in the past, some of which had catastrophic events as a vector.