When The Sahara Was Green

The little-known history of how the Sahara was transformed from a green and fertile land into the largest hot desert in the world The Sahara is the largest hot desert in the world, equal in size to China or the United States. Yet, this arid expanse was once a verdant, pleasant land, fed by rivers and lakes. The Sahara sustained abundant plant and animal life, such as Nile perch, turtles, crocodiles, and hippos, and attracted prehistoric hunters and herders. What transformed this land of lakes into a sea of sands? When the Sahara Was Green describes the remarkable history of Earth’s greatest desert—including why its climate changed, the impact this had on human populations, and how scientists uncovered the evidence for these extraordinary events. From the Sahara’s origins as savanna woodland and grassland to its current arid incarnation, Martin Williams takes us on a vivid journey through time. He describes how the desert’s ancient rocks were first fashioned, how dinosaurs roamed freely across the land, and how it was later covered in tall trees. Along the way, Williams addresses many questions: Why was the Sahara previously much wetter, and will it be so again? Did humans contribute to its desertification? What was the impact of extreme climatic episodes—such as prolonged droughts—upon the Sahara’s geology, ecology, and inhabitants? Williams also shows how plants, animals, and humans have adapted to the Sahara and what lessons we might learn for living in harmony with the harshest, driest conditions in an ever-changing global environment. A valuable look at how an iconic region has changed over millions of years, When the Sahara Was Green reveals the desert’s surprising past to reflect on its present, as well as its possible future.

Atlantis is not hiding at the bottom of the Atlantic Ocean but in plain view on top of the Sahara Desert. The prosperity of the Atlas Empire and the inundation of Atlantis corresponded to a lush Green Sahara started around 12,000 years ago. About 5700 years ago, the Green Sahara suddenly began to wither from the Atlas Basin, the heartland of the Atlas Empire. This is the rain shadow area of the Atlas Mountain range in today's Northeast Algeria and South Tunisia. When the water cycle stability in this standalone catchment was broken, the Chotts Megalakes (the Atlantic Sea) dried rapidly and the strong rain shadow effect of the Atlas Mountain became fully active. Deserts formed immediately in this area and gradually expanded east and south, like a spreading wildfire powered by the prevailing winds. This led to desertification and aridification in North Africa, West Asia, and the Mediterranean synchronously until this day. This timeline spans most of human history as we know it, including the thriving and dispersion of Atlas Empire, the rise and fall of Egypt, the prosperity and desolation of Mesopotamia, and the civilization shifts first from west to east and then from east to west across the Mediterranean and the Atlantic. The Atlantic Sea had a surface area over 26,000 sq km, which generated a great amount of water vapor, sufficient to eliminate the strong rain shadow effect of the Atlas Mountain, so that the Green Sahara was stabilized for about six thousand years. The Earth's precession (wobbling) has been blamed as the main control for the flipping between desert and green in the Sahara. This view has misled the academic society away from seeking the true primary cause for so long. The water cycle stability of the Sahara is governed by the non-linear relationship between precipitation and evaporation, which depends on surface conditions and atmospheric circulation. The Earth's precession only moved the water cycle closer to its unstable point so that a perturbation could trigger the transition from wet to dry state. This book explains the start and step-by-step spread of the Sahara Desert and its impact on West Asia and the Mediterranean regions. Archaeological records and paleoclimate data corroborate this new insight of the Sahara expansion process and the consequential desertification in these areas. The desertification process in Northwest China is an independent validation for the same control mechanism. Based on the new understanding, approaches are suggested to revive the Northwest China ecosystem, to turn the Sahara back to green and to ameliorate Australia to a water abundant country.

"Poetic language, attractive illustrations and a positive message about Islam, without any didacticism: a wonderful combination," declares Kirkus Reviews in a starred review. Lalla lives in the Muslim country of Mauritania, and more than anything, she wants to wear a malafa, the colorful cloth Mauritanian women, like her mama and big sister, wear to cover their heads and clothes in public. But it is not until Lalla realizes that a malafa is not just worn to show a woman's beauty and mystery or to honor tradition—a malafa for faith—that Lalla's mother agrees to slip a long cloth as blue as the ink in the Koran over Lalla's head, under her arm, and round and round her body. Then together, they pray. An author's note and glossary are included in the back of the book.

This book explains the structure and geographical and organisational mobility of criminal and migratory movements in the Sahara and the Sahel with a view to helping establish better development strategies for the region.

This open access book provides a multi-perspective approach to the caravan trade in the Sahara during the 19th century. Based on travelogues from European travelers, recently found Arab sources, historical maps and results from several expeditions, the book gives an overview of the historical periods of the caravan trade as well as detailed information about the infrastructure which was necessary to establish those trade networks. Included are a variety of unique historical and recent maps as well as remote sensing images of the important trade routes and the corresponding historic oases. To give a deeper understanding of how those trading networks work, aspects such as culturally influenced concepts of spatial orientation are discussed. The book aims to be a useful reference for the caravan trade in the Sahara, that can be recommended both to students and to specialists and researchers in the field of Geography, History and African Studies.

Demonstrates that the pre-Islamic Sahara was a more connected region than previously thought, with trade an essential linking element.

Catastrophic climate change overshadows the present and the future. Wrenching economic transformations have devastated workers and hollowed out communities. However, those fighting for jobs and those fighting for the planet have often been at odds. Does the world face two separate crises, environmental and economic? The promise of the Green New Deal is to tackle the threat of climate change through the empowerment of working people and the strengthening of democracy. In this view, the crisis of nature and the crisis of work must be addressed together—or they will not be addressed at all. This book brings together leading experts to explore the possibilities of the Green New Deal, emphasizing the future of work. Together, they examine transformations that are already underway and put forth bold new proposals that can provide jobs while reducing carbon consumption—building a world that is sustainable both economically and ecologically. Contributors also debate urgent questions: What is the value of a federal jobs program, or even a jobs guarantee? How do we alleviate the miseries and precarity of work? In key economic sectors, including energy, transportation, housing, agriculture, and care work, what kind of work is needed today? How does the New Deal provide guidance in addressing these questions, and how can a Green New Deal revive democracy? Above all, this book shows, the Green New Deal offers hope for a better tomorrow—but only if it accounts for work’s past transformations and shapes its future.

Quartz sand is anywhere and everywhere imaginable on the surface of the Earth. It forms the vast sandy Sahara and Arabian deserts where dunes can reach a staggering 180 meters in height. It makes up the world’s immense sandstone deposits, forms our beaches and is present in most soils around the globe. But where did all the sand come from?