Desertification: The Vicious Cycle Between Land Degradation and Climate Change
Although it’s commonly misperceived as a natural expansion of deserts, desertification of once fertile land is seen as one of the most pressing environmental issues facing the modern world, affecting agricultural land and soils around the globe. So, what causes soils to degrade and what could it lead to if desertification is not addressed?
What is desertification?
Desertification is the degradation of land in dry sub-humid, arid and semi-arid landscapes. Generally, this decline in the ‘quality’ of the land associated with desertification is thought to be caused by direct or indirect human activities, with consequences on the long-term loss of either biological productivity, ecological biodiversity or value to humans.1 This process is occurring in many regions across the world; from northern Chile to the Taklamakan Desert in China. While desertification is not a process commonly associated with Europe, climate change scenarios developed by the EU to investigate different ways climate change could affect precipitation and temperature increase in the continent show an increased vulnerability to desertification in the EU throughout this century. Portugal, Spain, Italy, Greece, Cyprus, Bulgaria and Romania have all been found to be the countries that will most acutely experience the negative consequences of desertification, partly due to their reliance on agricultural production in dryland areas.2,3
What are drylands?
Drylands are regions characterised by low precipitation. These regions cover over 40% of the world's land and host more than one-third of the global population.4
They provide a large part of the world’s grain and livestock, with up to 44% of the world’s cultivated land being found in drylands. Around 70 percent of people living in drylands earn their income from natural resources.4,5
Photo: A farmer in Turin, Italy checks his heavily damaged corn fields. In 2022, Italy experienced its worst drought in 70 years, threatening 30% of agricultural yields. (Stefano Guidi/Getty)
What causes desertification?
Desertification is caused by both human activity and climate change. The main human activities driving desertification are:
Overuse or inefficient use of water
This is often caused by poor or inefficient irrigation techniques, particularly in areas where readily available water supply is already reduced. Over time, this potentially leads to vegetation loss and eventually desertification.
Overgrazing and deforestation
Removing or consistently damaging vegetation that protects the land and keeps it moist and fertile is a key driver for the declining health and ability of soils to retain water and nutrients between seasons.
Research has found that land abandonment after initial agricultural use for extended periods can lead to soil being at risk of degradation and desertification. Having said that, a lack of human activity can also be beneficial for land by bringing about processes such as soil recovery, increased biodiversity or reforestation.4
While not a directly causal factor, climate change impacts can heighten the effects of human-induced land degradation. Climate change is mainly contributing to desertification through increasing temperatures and dry regions experiencing more frequent droughts causing land to become dry and be more prone to erosion in extreme weather events, such as flooding. In turn, degraded land releases carbon and nitrous oxide, worsening climate change and consequently further increasing land degradation.2,3
Consequences of desertification
Desertification has already affected the lives of 250 million people and could displace a further 135 million by 2045, making it one of the most serious environmental problems facing humanity.6
While not exhaustive, some of the main impacts of desertification include decreased food production, soil infertility, a decline in the land's ecological resilience to remain healthy through disturbances such as droughts, storms or heat waves, a reduction in local water quality, and increased emissions deriving from soil carbon. Inhabitants of dryland regions affected by this process often have to resolve to change the way they use their land. Examples of this include cover crops or rotational crops, which help to prevent soil erosion and drought and reforestation to reactive moisture and to generate bioldievisity.9 These are just some of the solutions which help to combat desertification and prevent biodiversity loss.
According to the UN, globally, around 24% of the land is currently degrading.10 The declines in productivity of cropland resulting from this can have wide-ranging social implications by causing food shortages, volatility and rise in food prices and even conflict and migration.2
Desertification in Europe
While Europe boasts a diverse ecological landscape, the dryland areas susceptible to desertification are common in parts of Southern and Eastern Europe, two notable regions for European food production. According to one recent study, the land in southern, central and eastern Europe with high vulnerability to desertification has increased by an area equivalent to the size of Greece and Slovakia combined in less than a decade. This is largely a result of changing weather patterns and increased human (and agricultural) activity. As water also becomes scarcer in many parts of Europe, the increased incidence of heat waves and droughts has fed further into a heightened vulnerability to desertification in a number of growing regions. Unfortunately, this is only expected to worsen as climate change impacts intensify. According to climate change models, temperatures are expected to rise by more than 2°C in some regions (e.g Spain) by the end of the century. Simultaneously, summer precipitation is expected to fall by 50% or more in southern European countries.3 Without active mitigation of desertified land, these changes could have severe and widespread impacts on not only the land and ecological systems, but also on food producers and ourselves as consumers of European grown produce.
Photo: In 2017, record-breaking drought in Spain dried resevoirs across the country. Leon, Spain. (Alvaro Fuente/NurPhoto/Getty)
Strategies on a global scale
The UN Convention to Combat Desertification (UNCCD) was adopted in 1994 and legally requires 197 countries to implement different actions to reverse and prevent desertification.
Italy is one of many countries that are not only responding to desertification in its own region, but is also working with other countries across the Mediterranean to help respond to environmental threats caused by droughts, forest fires and land degradation. One example includes the involvement in the Desertification Information System for the Mediterranean (DISMED) initiative, which aims to assess and monitor the extent, severity and trend of desertification and drought through a shared, common information system to combat desertification and prevent biodiversity loss.11
A small village in northern Ghana brought Wugulu close to a social and economic collapse due to longer than expected dry seasons, bush fires, poor farming practices and overgrazing. In 2000 with the support of Friends of the Earth-Ghana and the Japan Fund for Global Environment, a tree planting and community initiative was launched, addressing deforestation caused by excessive felling of trees. As a result, 2,000 acacia saplings were planted on 13 acres of land. Harvesting of the trees began in 2005, giving the villagers a sustainable source of trees for home use and income-generating purposes. Due to the village’s success in preserving the environment and promoting economic stability, similar projects are going on throughout the country.11
Apart from increasing political awareness, countries like Italy and Ghana among others are facing the challenges head-on by focusing on mainstreaming land degradation issues by adapting them into the overall policy plans of both developing countries and development agencies by improving the coordination between donors, national focal points and ministries.
At a European Level, the Soil Framework Directive was proposed in 2006 and called for EU Member States and Non-EU Member States to identify areas at risk of soil degradation, define targets for soil protection, and carry out programmes to achieve these targets.3 Unfortunately, in 2014 the proposal was withdrawn due to lack of support. Today, the EU Soil Strategy for 2030 takes existing legislative instruments with relevance for soil protection to set out a framework for the sustainable use of soil. The Strategy aims to achieve good soil health by 2050 by encompassing a combination of new voluntary and legally binding measures, some of which include enhancing the protection of organic soils and peatlands; supporting the Commission initiative for sustainable carbon cycles, by rewarding the practices of carbon sequestration in agricultural soils; and support the reuse of excavated soils by introducing a ‘passport’ to guarantee they are transported, treated and reused in a safe way.12,13 Examples of existing instruments related to soil are in the Common Agricultural Policy, as farming practices are at the heart of soil degradation or conservation.
Photo: In response to desertification, community members of Wuwei, China lay down sand barriers made of straw to create viable sowing ground for the drought-hardy Saxaul plant. (Wang HE/Getty)
Carbon farming - a practical solution?
On a farm level, a practice that has been gaining traction has been carbon farming, referring to different approaches to farming that increase carbon stored in the soil. Examples of effective carbon practices include the use of cover crops, agroforestry, limiting tillage or embracing conservation tillage practices, establishing permanent grasslands in uncultivated lands and limiting the number of grazing animals per field. At a glance, by enhancing the biodiversity of the soil, these increase the organic carbon stored in the soil which in turn, by affecting their chemical and physical properties, improve the soil’s water infiltration rates, plant nutrient availability and moisture holding capacity.7
The EU is promoting incentives for Carbon Farming in its Common Agricultural Policy (CAP), hopefully making carbon sequestration and healthy soils resilient to desertification an attractive and viable option for farmers across the continent. In addition, aiming to turn agricultural lands into carbon sinks and therefore mitigating climate change, this policy tool can in the long term, reduce the threats of climate change on desertification.8
What do you think countries around the world should coordinate efforts to address desertification?
Climate migration: Displacement caused by climate change.