The outcomes of an assessment of land degradation and restoration launched in April 2018 draw a grim picture of the future if land degradation continues to spread.
Produced by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the three-year IPBES Assessment Report on Land Degradation and Restoration was written by more than 100 leading experts from 45 countries.
Rapid expansion and unsustainable management of croplands and grazing lands is the most extensive global direct driver of land degradation, causing significant loss of biodiversity and ecosystem services. This has reached ‘critical’ levels in many parts of the world, the report says.
The wellbeing of at least 3.2 billion people is undermined by the degradation of the Earth’s land surface through human activities, according to the authors. Moreover, they warn that these developments are pushing the planet towards a sixth mass species extinction and point out that land degradation is a major driver of climate change.
Wetlands have been particularly hard hit by land degradation, the authors say. There have been losses of 87 per cent in wetland areas since the start of the modern era – with 54 per cent lost since 1900.
There are many ways that land degradation manifests in: land abandonment, declining populations of wild species, deterioration of soil health and loss of soil, rangelands and fresh water, as well as deforestation.
The underlying drivers of land degradation, says the report, are the high-consumption lifestyles in the most developed economies, combined with rising consumption in developing and emerging economies. High and rising per capita consumption, amplified by continued population growth in many parts of the world, can drive unsustainable levels of agricultural expansion, natural resource and mineral extraction, and urbanisation – typically leading to greater levels of land degradation.
By 2014, more than 1.5 billion hectares of natural ecosystems had been converted to croplands.
Less than 25 per cent of the Earth’s land surface has escaped substantial impacts of human activity – and by 2050, the IPBES experts estimate, this share will have fallen to less than ten per cent.
The report says that increasing demand for food and biofuels will likely lead to a continued increase in nutrient and chemical inputs and a shift towards industrialised livestock production systems, with pesticide and fertiliser use expected to double by 2050.
The authors forecast that in just over three decades from now, an estimated four billion people will be living in drylands. By then, it is likely that land degradation, together with the closely related problems of climate change, will have forced 50-700 million people to migrate.
Decreasing land productivity also makes societies more vulnerable to social instability – particularly in dryland areas, where years with extremely low rainfall have been associated with an increase of up to 45 per cent in violent conflict.
By 2050, the authors of the report say, the combination of land degradation and climate change is predicted to reduce global crop yields by an average of ten per cent, and by up to 50 per cent 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.
What can be done to avoid further agricultural expansion into native habitats? The authors recommend to achieve yield increases on the existing farmlands, shifting towards less land degrading diets, such as those with more plant-based foods and less animal protein from unsustainable sources, and reducing food loss and waste.
Stopping and reversing land degradation is not only vital to ensure food security, reduce climate change and protect biodiversity, according to the authors, it also makes sense economically. The report found that higher employment and other benefits of land restoration often exceeded by far the costs involved.
On average, the benefits of restoration are ten times higher than the costs. For regions like Asia and Africa, the cost of inaction in the face of land degradation is at least three times higher than the cost of action.
On the other hand, the dangers of land degradation costs the equivalent of about ten per cent of the world’s annual gross product in 2010 through the loss of biodiversity and ecosystem services.