MEDELLIN, COLOMBIAMore than 75 percent of Earth’s land areas are substantially degraded, undermining the well-being of 3.2 billion people, according to the world’s first comprehensive, evidence-based assessment. These lands that have either become deserts, are polluted, or have been deforested and converted to agricultural production are also the main causes of species extinctions.
If this trend continues, 95 percent of the Earth’s land areas could become degraded by 2050. That would potentially force hundreds of millions of people to migrate, as food production collapses in many places, the report warns. (Learn more about biodiversity under threat.)
“Land degradation, biodiversity loss, and climate change are three different faces of the same central challenge: the increasingly dangerous impact of our choices on the health of our natural environment,” said Sir Robert Watson, chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), which produced the report (launched Monday in Medellin, Colombia).
IPBES is the "IPCC for biodiversity"—a scientific assessment of the status of non-human life that makes up the Earth’s life-support system. The land degradation assessment took three years and more than 100 leading experts from 45 countries.
Rapid expansion and unsustainable management of croplands and grazing lands is the main driver of land degradation, causing significant loss of biodiversity and impacting food security, water purification, the provision of energy, and other contributions of nature essential to people. This has reached “critical levels” in many parts of the world, Watson said in an interview.
Wetlands have been hit hardest, with 87 percent lost globally in the last 300 years. Some 54 percent have been lost since 1900. Wetlands continue to be destroyed in Southeast Asia and the Congo region of Africa, mainly to plant oil palm.
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, are driving unsustainable levels of agricultural expansion, natural resource and mineral extraction, and urbanization.
“We’ve know about this for over 20 years but it is only getting worse,” said Luca Montanarella, a soil scientist from Italy and co-chair of the assessment.
Land degradation is rarely considered an urgent issue by most governments, even though many have signed an international agreement to reach land degradation neutrality by 2030. “We need to find a stable balance between our lifestyle and our impacts on nature,” Montanarella said in an interview in Medellin.
Ending land degradation and restoring degraded land would get humanity one third of the way to keeping global warming below 2°C, the target climate scientists say we need to avoid the most devastating impacts. Deforestation alone accounts for 10 percent of all human-induced emissions.
For developing regions like parts of Asia and Africa, the cost of inaction in the face of land degradation is at least three times higher than the cost of action. And the benefits of restoration are 10 times higher than the costs, the report found.
Ending production subsidies in agriculture, fisheries, energy, and other sectors would go a long way to reducing pressure on nature. Roughly 25 percent of Africa has shifted out of cattle and sheep production simply because it has become too dry and unproductive to be profitable, said Robert Scholes, a South African ecologist and co-chair of the assessment.
“These lands are reverting back to wildlife, which are better adapted to those conditions,” Scholes said. “The same things is happening in Australia.”
There are many proven approaches to reversing these trends, including urban planning, replanting with native species, green infrastructure development, remediation of contaminated and sealed soils (e.g. under asphalt), wastewater treatment, and river channel restoration. Land needs to be managed at a landscape scale, where the needs of agriculture, industry, and urban areas can be balanced in a holistic way, Scholes said.
Better, more open-access information on the impacts of traded commodities is also needed, he adds. Many rich countries “offshore” their environmental impacts by importing huge quantities of food, resources, and products from other countries. The European Union imports 30 to 40 percent of its food, for example.
“Through this report, the global community of experts has delivered a frank and urgent warning, with clear options to address dire environmental damage,” said Watson.