The Sahara is undoubtedly the largest hot desert and harshest environments of the world. It engulfs most of the nations of North Africa, including Algeria, Egypt, Mali, Libya, Morocco, Mauritania, Western Sahara, Niger and Tunisia. However, reports have suggested that the desert is expanding more at an average of around 10 percent over the past century. It is expanding towards more tropical terrains of Chad, thereby turning the areas of green vegetation, which were once used by farming into barren grounds and dry.
Typically, deserts are defined to be places that get less than 25 centimetres (10 inches) of rainfall annually, as recorded by the U.S Geological Survey. Considering the same, the Sahara Desert is known to be the third-largest one in the world with a total surface area of 9.6 million square kilometres (3.6 million square miles). While throwing light on the area coverage of cold deserts, the frozen desert of Antarctica spans about 14.2 million square kilometres (5.5 million square miles) and the Arctic desert has a total regio of around 13.98 million square kilometres (5.4 million square miles).
Strong Driving Forces of Area Expansion
Researchers of the study has examined the seasonal cycles of rainfall and temperature all across Africa due to global warming and climate change, observing the records from 1920-2013. While analysing the records, they observed that the precipitation trend in Sahel (a typical semiarid region which links the savannas of Sudan to Sahara) is facing a drastic declining flow. Thus, boundaries of many deserts contract and expand seasonally, since the conditions fluctuates between drier and wetter.
Generally, climate changes driven by the abnormalities in sea-surface temperatures is considered to be the reason for overall increasing size of the Sahara desert. This, in turn, affects the precipitation level on land, affect surface temperature and their impact can expectantly last for several decades.
This transition in the temperature pattern and geographical periphery due to global warming and climate change is affecting the lives of wildlife and inhabitants. However, as the regions which, are cultivated for food production are increasingly drier, they are becoming more vulnerable to droughts thereby facing a greater threat of famine for the inhabitants.