One of the greatest environmental challenges of this decade has been the ongoing land degradation in our drylands including arid, semi-arid and dry sub-humid areas of the world. Driven by multiple factors, but predominantly by climate change and human activities, this process, known as, desertification not only threatens present and future food security and livelihood of more than 2 billion people but it can also exacerbate climate change-induced extreme weather events. Desertification is not just confined to people inhabiting deserts and its surroundings but it has been expanding much beyond that. Over 2.7 billion people live in the drylands which are most susceptible to desertification owing to water scarcity from lesser and fluctuating rainfall and poor soil fertility. 90 per cent such people come from developing nations. Today, drylands account for 38 per cent of the Earth’s land area which includes regions of North and southern Africa, western North America, Australia, the Middle East and Central Asia.
While desertification may have many factors contributing to it but the poor use of land and its management, and global warming causing climate change have been the major ones. Natural forces breaking down and removing rock and soil, eroding the topsoil layer or human activities such as ploughing, overgrazing of livestock, over-cultivation of crops, poor irrigation practices and deforestation have been exacerbating the ongoing land degradation. The loss of soil fertility, loss of vegetation cover, declining water table can further reduce land quality, making it dry and severely degraded. Climate change can result in intense and frequent periods of drought or floods; the variation and fluctuation of rainfalls due to climate change may further dry the land in case of lower rains, and it can erode the soil in case of floods. For instance, in the latter half of the 19th century, the Sahel region of Africa was lashed with intense drought and related desertification which study suggests were due to natural variations in the Atlantic, Pacific and the Indian ocean. However, the warming Mediterranean sea led to some recovery of rain later. The instances of wildfires have shot up in recent years. Warmer temperature conditions have made the conditions dry, making it more susceptible to catching fire and leaving degraded pieces of land. Deforestation leads to loosening of soil as the trees are cleared or uprooted, causing more erosion and contributing to desertification.
The impacts can be seen in the form of the global loss of biodiversity and a drastic reduction of fertile land. As per a study, desertification and drought claims around 12 million hectares of fecund land, annually, which is equivalent to a loss of 20 million tonnes of grain! People from poorer nations already plagued with poor governance, poverty and inequality and with no adequate economic support to farmers, are more prone to challenges of desertification as they depend on agriculture, for their food and livelihood. Additionally, desertification is also expected to increase sand and dust storms as the wind can easily blow away loose sand and soil particles from desiccated land.
We can’t predict how the rate of desertification would shift in future, with certainty. However, as climate change means warmer temperature, the rate of evaporation would be more, expanding the dry area further. Experts warn that if we continue with the emission of greenhouse gases, drylands could expand between 50 and 56 per cent of Earth’s land surface! The sure shot way to restrain desertification is limiting greenhouse gases emission and thus limiting global warming. Further, with sustainable land management and land degradation neutrality, we can reduce the rate of desertification to some extent, if not completely.