Land degradation and desertification concern us all. They reinforce the effects of global warming, impacting on soils, vegetation, and the hydrological cycle.
Desertification, or degradation of terrestrial ecosystems, occurs when there is overexploitation of land beyond their productive capacities, resulting from unsustainable management practices. This is especially true in drylands (around 41% of all land; and home to more than one billion people). The degradation of land resources (soil, water, vegetative cover) put vulnerable populations at higher risk due to the insufficient availability of food, energy, housing, and income. This in turn increases the pressure put on productive land, which results in its degradation. This vicious circle is a primary cause of desertification and the loss of agricultural land. With global warming, the vicious circle is now intensifying. In Africa, millions are surviving on land with diminished and declining productivity.
Desertification and drought are slow-moving processes that directly threaten the incomes of rural populations, often forcing smallholder farming families to migrate. The abandonment of agricultural activity may, in tandem with climate change, be the largest driving of biodiversity loss by 2050.
Agriculture contributes to a fifth of global greenhouse gas emissions, and it is estimated that 80% of these agricultural emissions are produced in developing countries. Agriculture also accounts for 70-85% of water use and 70% of this water for agriculture is drawn from aquifers, streams and lakes. The anticipated increase in demand for water for food production, projected to double by 2050, will place yet more stress on water management and incur an even heavier toll on agricultural land.
Acting on climate change in agriculture with innovative options that integrate the management of land resources can improve the conditions of human populations and ecosystems and prevent the loss of fertile soil and biodiversity. In marginal rural populations, sustainable agroforestry and livestock programs combined with widened market access and adequate energy resources (including renewable energy options) can increase incomes and guarantee food security.
The impact of climate change may lead countries to respond with approaches that promote collective ownership of and responsibility for the long-term management of ecosystems and the services they provide. These services include soil fertility and water conservation as necessary conditions for food security, poverty reduction and biodiversity protection.
Carbon sequestration in terrestrial ecosystems plays a major role in mitigating climate change and contributes to the implementation of adaptive strategies in agriculture. Climate smart agriculture, sustainable land-, forest- and water-management are all part of this potential solution. Sustainable land management contributes to increased carbon stocks in the soil and plant biomass. Such management techniques include integrated erosion control, afforestation and woodland regeneration, agro-forestry, silvo-pastoralism, conservation agriculture, mobile livestock management, water conservation and harvesting, and the sustainable use of legumes. According to the IPCC, the total carbon stock in drylands is 36% of the total carbon stock in terrestrial ecosystems, thus making it a significant potential sink for carbon sequestration.
Possibly the most significant long-term contribution within a process of combating land degradation and desertification is the identification and enhancement of agriculture’s capacity to mitigate climate change. This would include creating a broad coalition of those with a stake in agricultural land, especially focusing on smallholder farmers in developing countries.
Sergio Zelaya is the Senior Land and Water Officer for the Food and Agriculture Organization (FAO), part of the United Nations.