Global soils are the source of all life on land but their future looks “bleak” without action to halt degradation, according to the authors of a UN report.
A quarter of all the animal species on Earth live beneath our feet and provide the nutrients for all food. Soils also store as much carbon as all plants above ground and are therefore critical in tackling the climate emergency. But there also are major gaps in knowledge, according to the UN Food and Agriculture Organization’s (FAO) report, which is the first on the global state of biodiversity in soils.
The report was compiled by 300 scientists, who describe the worsening state of soils as at least as important as the climate crisis and destruction of the natural world above ground. Crucially, it takes thousands of years for soils to form, meaning urgent protection and restoration of the soils that remain is needed.
The scientists describe soils as like the skin of the living world, vital but thin and fragile, and easily damaged by intensive farming, forest destruction, pollution and global heating.
“Soil organisms play a crucial role in our everyday life by working to sustain life on Earth,” said Ronald Vargas, of the FAO and the secretary of the Global Soil Partnership.
Prof Richard Bardgett, of the University of Manchester, who was a lead author of the report, said: “There is a vast reservoir of biodiversity living in the soil that is out of sight and is generally out of mind. But few things matter more to humans because we rely on the soil to produce food. There’s now pretty strong evidence that a large proportion of the Earth’s surface has been degraded as a result of human activities.”
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Since the Industrial Revolution, about 135bn tonnes of soil has been lost from farmland, according to Prof Rattan Lal, the 2020 winner of the World Food prize.
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People should be worried, said Bardgett. “If things carry on as they are, the outlook is bleak, unquestionably. But I think it’s not too late to introduce measures now.”
Prof Nico Eisenhauer, of Leipzig University, another lead author of the report, said: “It is a major issue that we are dependent on this thin layer that is sometimes just a couple of centimetres, sometimes several metres, but a very vulnerable, living skin.”
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Soils simultaneously produce food, store carbon and purify water, he said, so they are “at least as important” as the climate and above-ground biodiversity crises. “If you’re