Worsening land degradation caused by human activities is undermining the well-being of two fifths of humanity, driving species extinctions and intensifying climate change. It is also a major contributor to mass human migration and increased conflict, according to the world’s first comprehensive evidence-based assessment of land degradation and restoration.
The dangers of land degradation, which cost the equivalent of about 10% of the world’s annual gross product in 2010 through the loss of biodiversity and ecosystem services, are detailed for policymakers, together with a catalogue of corrective options, in the three-year assessment report by more than 100 leading experts from 45 countries, launched today.
Produced by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (
IPBES), the report was approved at the 6th session of the IPBES Plenary in Medellín, Colombia. IPBES has 129 State Members.
“With negative impacts on the well-being of at least 3.2 billion people, the degradation of the Earth’s land surface through human activities is pushing the planet towards a sixth mass species extinction,”
The IPBES report finds that land degradation is a major contributor to climate change, with deforestation alone contributing about 10% of all human-induced greenhouse gas emissions. Another major driver of the changing climate has been the release of carbon previously stored in the soil, with land degradation between 2000 and 2009 responsible for annual global emissions of up to 4.4 billion tonnes of CO2.
“By 2050, the combination of land degradation and climate change is predicted to reduce global crop yields by an average of 10%, and by up to 50% in some regions. In the future, most degradation will occur in Central and South America, sub-Saharan Africa and Asia – the areas with the most land still remaining that is suitable for agriculture.”
Climate Change Links Land degradation is a major contributor to climate change, and climate change is foreseen as a leading driver of biodiversity loss (along with crop agriculture and infrastructure development) through 2050.
The contribution of land degradation to climate change includes the release of carbon sequestered in soil. Between 2000 and 2009, land degradation was responsible for annual global emissions of 3.6–4.4 billion tonnes of CO2.
Over the past 200 years, soil organic carbon, an indicator of soil health, has dropped an estimated 8% globally (176 Gt C - equivalent to the carbon that would be lost from clearing an area of tropical forest approximately the size of Australia).
Without urgent action, further losses of 36 gigatons of carbon from soils - especially from Sub-Saharan Africa – is projected by 2050 (equivalent to nearly 20 years of emissions from the global transportation sector - all freight and passenger traffic by land, air, water and sea). The main processes include deforestation and forest degradation, the drying and burning of peatlands, and the decline of carbon content in many cultivated soils and rangelands because of excessive disturbance and insufficient return of organic matter to the soil.
Deforestation alone contributes approximately 10% of all human-induced greenhouse gas emissions, and can further alter the climate through changes in surface reflectivity and the generation of dust particles.
In mountainous and high latitude regions, permafrost melt and glacier retreat will result in mass land movements such as landslides and surface subsidence (cave-ins, sinking) and higher greenhouse gas emissions. In forests, the likelihood of wildfires, pest and disease outbreaks increases in scenarios where droughts and hot spells are projected to be more frequent.
The impacts of climate change on land degradation include accelerated soil erosion on degrade lands as a result of more extreme weather events, increased risk of forest fires, and changes in the distribution of invasive species, pests and pathogens.
Strong 2-way interaction between climate change and land degradation mean the issues are best addressed in a coordinated way.
Some activities aimed at climate change mitigation can increase the risk of land degradation and biodiversity loss - e.g. expansion of bioenergy crops. Planting trees where they did not historically occur (afforestation), can have an impact similar to deforestation, including the reduction of biodiversity and disruption of water, energy and nutrient cycles.
Avoiding, reducing and reversing land degradation could provide more than a third of the most cost-effective greenhouse gas mitigation activities needed by 2030 to keep global warming under 2°C, increase food and water security, and contribute to the avoidance of conflict and migration.
https://www.ipbes.net/news/media-release-worsening-worldwide-land-degradation-now-%E2%80%98critical%E2%80%99-undermining-well-being-32