What are drylands and why are they important? Present in each continent and covering over 40 per cent of the earth, drylands generally refer to arid, semi-arid and dry subhumid areas, and are home to more than 2 billion people, or one in three people in the world. Drylands are key to global food and nutrition security for the whole planet, with up to 44 per cent of the world’s cultivated systems located in drylands.
Drylands also support important ecosystems ranging from rangelands and grasslands to semi-desert, and host 1.1 billion hectares of forest – more than a quarter of the world’s forest area.1 Rangelands support 50 per cent of the world’s livestock and are habitats for wildlife, while livestock production and croplands dominate in more arid and dry subhumid areas, respectively. Drylands, despite their relative levels of aridity, contain a great variety of biodiversity, with many animal and plant species and habitats found only in drylands and playing a vital role in the livelihoods of many dryland inhabitants (IUCN, 2012). They are also important for climate regulation: according to the Millennium Ecosystem Assessment (UN, 2005, chapter 22), total dryland soil organic and inorganic carbon reserves make up 27 per cent and 97 per cent, respectively, of the global soil organic and soil inorganic global carbon reserves.
Drylands are under threat across the world. Despite their importance, drylands are being degraded through a complex combination of climatic (e.g. decreasing rainfall and evaporation of water) and human stresses, such as unsustainable farming techniques, mining and overgrazing. Water scarcity is increasing, and in many areas, desertification is expanding with serious human and environmental consequences.
While soil can take up to thousands of years to build up, desertification of drylands, where soils are already fragile, is happening at an alarming rate; today, the pace of arable land degradation is estimated at 30 to 35 times the historical rate (UN, 2016 web). According to the United Nations Convention to Combat Desertification (UNCCD), desertification and degradation could be costing developing countries up to 8 per cent of their gross domestic product a year (EMG, 2012). The UNCCD also stresses that the costs are not in economic terms alone, but encompass social and well-being dimensions (UN, 2013 web); for example, desertification of drylands also leads to migration, with some 50 million people estimated as being displaced within the next 10 years (UNCCD, 2016 web).
Investing in drylands pays off
Investing in drylands, therefore, pays significant human and environmental dividends. Environment-friendly and water-efficient agriculture for smallholders is key to reducing poverty, boosting smallholder adaptation to climate change, as well as rehabilitating degraded lands. Improving smallholder productivity in drylands can be particularly challenging compared to other areas, but the aggregate benefits are considerable given the high combined populations (EMG, 2012), as well as the total land area they represent.
Global calls to action
Despite the importance of drylands and the urgency of the need to protect them, they have not always attracted the investment they deserve – this may be due to misconceptions of drylands being ‘wastelands’ without potential (IUCN, 2009). Things began to change when, during the 1992 Rio Earth Summit, desertification, climate change and the loss of biodiversity were identified as the planet’s greatest challenges to sustainable development. The United Nations Convention to Combat Desertification was established in 1994, and the Convention addresses specifically the arid, semi-arid and dry sub-humid areas, where some of the most important but vulnerable ecosystems and people can be found. Today, the Sustainable Development Goals (SDGs) also reaffirm the importance of drylands, “recognis(ing) that social and economic development depends on the sustainable management of our planet’s natural resources”;2 and pledging to conserve and sustainably use drylands, as expressed in Goal 15.1: “By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements”.