The world’s soils may be holding far more carbon than climate models have long assumed. New research released Wednesday finds that topsoils store about 45% more carbon compared to earlier estimates, adding weight to calls to put soil health much closer to the center of climate change planning.
The analysis — produced by the International Union for Conservation of Nature, Save Soil, Aurora, and the World Commission on Environmental Law — estimates that the top meter of soil holds about 2,822 gigatons of carbon, which shows how much could be lost if soil degradation accelerates. For context, global greenhouse gas emissions in 2024 were 57.7 gigatons.
But scientists say that this carbon reservoir comes with a warning: The system only works if soils remain healthy, but soil health is declining in many parts of the world. Degradation from erosion, nutrient loss, and declining organic matter sharply reduces how much carbon they can retain. Current rates of degradation also risk pushing stored carbon back into the atmosphere, an estimated 4.81 billion metric tons of carbon dioxide each year — roughly the annual emissions of the U.S. in 2023.