disciplinary fieldwork in Africa, Australia, India and China, he has made original and internationally recognised contributions to our understanding of the Quaternary geology, geomorphology, soils, climatology, hydrology, geo-archaeology, prehistoric environments and desertification. He has worked closely with teams of archaeologists. He is best known for his work in the Nile Valley, erosion in Australia and desertification. He contributed to many important international committees dealing with aridification. He is an excellent communicator of his science and its implications for humanity's future.
Williams's many books include Climate Change in Deserts; Nile Waters, Saharan Sands; and The Nile Basin.
He applied the “Page 99 Test” to his new book, When the Sahara Was Green: How Our Greatest Desert Came to Be, and reported the following:
Page 99 is part of a section called "Herodotus and the Libyan War on Saharan Winds" which is part of a chapter called "A Handful of Dust."Visit Martin Williams's website.In Book Four of The Histories, Herodotus (c. 485-425 BC) tells the story (perhaps quite apocryphal) of a group of people from the small town of Sirte in northern Libya who were enraged by the south wind (most likely the khamsin) because it had dried out the water in their cisterns. In a quite irrational fury, the people of Sirte declared war on the wind and marched into the desert, where ‘the wind blew and buried them in sand’.To my surprise, I found that page 99 is a curiously good indicator of what the book is about, namely the contrast between the present-day austere and waterless landscape of the Sahara and the evidence that it was once much wetter and able to support an abundance of plant and animal life as well as flourishing human societies.
Later in Book Four Herodotus describes ‘salt-hills and springs’ in Libya and noted that ‘the houses are all built of salt-blocks – an indication that there is no rain in this part of Libya, for if there were, salt walls would collapse. The salt which is mined there is of two colours, white and purple. South of the sand-belt, in the interior, lies a waterless desert, without rain or trees or animal life, or a drop of moisture of any kind.’ When I visited Kufra Oasis in southern Libya in 1962 and 1963, the main road was made of rock salt, a clear sign that rain was very rare.
Another example cited by Herodotus involved the Persian army of 50,000 soldiers led by King Cambyses II, the son of Cyrus the Great. They were on their way to quell a rebellion in Siwa Oasis in the Western Desert of Egypt in about 524 BC when they were caught in a sandstorm and never seen again. In the account told to Herodotus ‘a southerly wind [again, very probably the khamsin wind] of extreme violence drove the sand over them [the Persian soldiers] in heaps as they were taking their mid-day meal, so that they disappeared for ever.’ In light of the engrained memory of these ancient disasters it is small wonder that in his great poem The Waste Land, T.S. Eliot wrote ‘I will show you fear in a handful of dust’.
However, as we saw in Chapter 3, life in the desert has not always been as grim as it was during the time when the army of Cambyses II was engulfed in sand. Only a few thousand years before Herodotus visited Egypt, numerous small bands of pastoralists grazed their herds of cattle across what is now the arid Sahara. They left behind them a legacy of rock paintings depicting Neolithic cattle, sheep and goats. Earlier still, as we saw in chapter 3, the prehistoric hunters of the Sahara carved rock engravings showing antelopes, giraffes, elephants and other large animals that live today in the savanna lands of East Africa. In those times…”
Page 99 tells us a small part of the story about Saharan desert dust, as seen through the eyes of the Greek historian and inveterate traveller Herodotus, nearly 2,500 years ago. Herodotus visited Egypt and asked the people he met for information about that mysterious land. His curiosity was aroused by tales of houses made of salt. He considered this strong evidence of how little rain ever fell in that region. He also described how a mighty sandstorm engulfed an invading Persian army. Page 99 concludes by reminding us that the desert was not always dry. Just a few thousand years earlier, herds of domestic cattle were grazing throughout the Sahara at a time when it was a well-watered green and pleasant land. The memory of those times is preserved in prehistoric rock engravings and multi-coloured paintings on favourable rock outcrops across what is now a dry and desolate wilderness.
My aim in writing this book was to draw upon my own experience of the Sahara and to ask why it was once wetter and able to support so much life and why it is no longer able to do so. Did humans cause the Sahara to dry out or has the climate changed? If so, why? I also discuss the causes of prolonged droughts and their impacts upon people living on the desert margins. I conclude by showing how the human inhabitants of the Sahara have adapted so successfully to life in this harsh environment.
--Marshal Zeringue