Like a broken cell phone that can only text or take pictures, but not make a single call, more than 75 percent of the Earth’s land areas have lost some or most of their functions, undermining the well-being of the 3.2 billion people that rely on them to produce food crops, provide clean water, control flooding and more.

These once-productive lands have either become deserts, are polluted, or have been deforested and converted for unsustainable agricultural production. This is a major contributor to increased conflict and mass human migration, and left unchecked, could force as many as 700 million to migrate by 2050, according to the world’s first comprehensive evidence-based assessment of land degradation, released today in Medellín, Colombia.

Deforestation in Madagascar. Image: Dudarev Mikhail/Shutterstock

Land degradation—including deforestation, soil erosion, and salinity and pollution of fresh water systems—is also driving species to extinction and aggravating the effects of climate change, the report concludes. It was written by more than 100 leading experts from 45 countries for the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). 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. A major companion report was released Friday documenting the rapid and dangerous decline in biodiversity. It called for fundamental changes in how we live, run our societies, and the economy.

“This is an extremely urgent issue that we need to address yesterday,” said Robert Scholes, a South African ecologist and co-chair of the assessment. “Land degradation is having the single biggest impact on the well-being of humanity,” Scholes said in an interview in Medellín.

Human activities, mainly those involving agriculture and urbanization, have destroyed or degraded topsoil, forests, and other natural vegetation and water resources nearly everywhere, the report found. Wetlands have been hit hardest, with 87 percent lost globally in the last 300 years. Wetlands continue to be destroyed in southeast Asia and the Congo region, mainly to plant oil palm trees.

Less than 25 percent of the Earth’s land surface has escaped the substantial impacts of human activity—and by 2050, this will have fallen to less than 10 percent. Most of these future land losses will be in Central and South America, sub-Saharan Africa, and Asia. The only places left relatively unaffected will be polar regions and tundra, high mountains, and deserts, the report projects.

Ending land degradation is “an urgent priority to protect the biodiversity and ecosystem services vital to all life on Earth and to ensure human well-being,” said Luca Montanarella, a soil scientist from Italy and co-chair of the assessment.

“We’ve know about this for over 20 years, but it is only getting worse,” Montanarella said in an interview in Medellín. There is little public awareness and it is not considered an urgent issue by most governments. The only way to stop the decline is at the local level, and through the choices each of us make, he said.

River bank erosion in Bangladesh. Image: Sangib Kumar Barman/Shutterstock

Those choices include choosing to eat less meat and buying food from local growers who use the most sustainable farming practices. Up to 40 percent of food is wasted globally at various points, from farms to overstuffed refrigerators, said Robert Watson, IPBES Chair. Countries also need to end their production subsidies in agriculture, fisheries, energy, and other sectors, Watson told Motherboard.

Rich countries need to take responsibility for the impacts that their consumption of imported products may have. The country landscape of the United Kingdom is a tourist attraction because the country imports 35 to 40 percent of its food from other countries, said Watson. “People don’t see the impacts of their consumption.”

Ending land degradation and restoring damaged lands would provide more than one third of the most cost-effective greenhouse gas mitigation activities required by 2030 to keep global warming to below 2°C. And doing this would cost at least three times less than doing nothing and create much better livelihoods and jobs for local people, said Watson.

“Implementing the right actions to combat land degradation can transform the lives of millions of people across the planet, but this will become more difficult and more costly the longer we take to act,” he said.