# Drought: A Common Environmental Disaster
## 5 Environmental Degradation and Drought  
Desertification is the degradation of arid, semi-arid and dry sub-humid environments when productivity is limited by water availability. Drought has an impact on both ecological and economic systems. Drought, similarly to land deterioration, affects almost every section of the globe, even humid areas. Land and other environmental components [97; 98], such as vegetation, are critical resources for food production and other ecosystem goods and services, such as biodiversity conservation, hydrological regime regulation, soil nutrient cycling and carbon storage, among others [98]. The most important geo-resource or natural capital asset is, without a doubt, productive land and fertile soil [8]. Human well-being and sustainable livelihoods are fully dependent on and closely tied to the health and productivity of the land for those people who rely largely on land as their principal asset [98], especially the poor rural; in a situation where these areas are prone to drought, livelihood will be endangered in such regions. The world's croplands and pastures grew by 154 million hectares between 1985 and 2005. Humans have removed or converted 70 percent of grassland, 50 percent of savannah, 45 percent of temperate deciduous forest and 27 percent of tropical forest biome for agriculture in the last two centuries [99; 100]. Agriculture is thought to be responsible for roughly 80% of global deforestation [101], and productive land is growing scarce. Increased demand for productive land and water resources is caused by population growth, climate change, unsustainable land use, drought land degradation and expanding metropolitan areas [99]. At the same time, competition for productive land increases due to the growing demand for food, fodder and agricultural raw materials for industrial and energy use. According to a study titled \"The Economics of Desertification, Land Degradation, and Drought: Methodologies and Analysis for Decision Making\", land degradation costs the global community up to 5% of total agricultural GDP, amounting to USD 490 billion every year [102]. Land degradation has a wide range of direct economic implications of drought at the country level, with other countries suffering even greater losses due to drought episodes [103; 104]. Drought has an impact on both ecological and economic systems [104]; drought, similarly to land deterioration, affects most of the world's regions, including South Africa. The fraction of the Earth's land area affected by severe drought more than doubled from the 1970s to the early 2000s [99; 100]. Even though the world's drylands remain the most vulnerable to desertification, land degradation and drought, land degradation is a global occurrence, with 78 percent of the total degraded land occurring in terrestrial ecosystems other than drylands [105]. The links between land degradation and two other significant challenges of global environmental change are climate change and biodiversity loss, which provide another strong reason to see drought in its global context. Climate change adaptation and mitigation are inextricably linked, and land management provides a mechanism for tackling both. Maintaining and improving land quality contributes to biodiversity conservation and sustainable management, as well as providing a viable alternative to deforestation and ecosystem deterioration [106; 107]. According to a recent study, rising global temperatures may cause catastrophic events to occur more frequently and with higher severity in a globally synchronised manner. On a global scale, this might drastically diminish our resistance to drought and food system disturbances [71]. With its focus on improving soil structure and land cover, Sustainable Land Management (SLM) has the potential to make significant progress toward three critical global sustainability goals related to drought, namely, food security, energy access and water availability.