A new study published in Science reveals that the dried bed of the Aral Sea has released an estimated 825 million tons of carbon dioxide into the atmosphere since 1960. That is roughly three times Spain's annual emissions and comes from a source largely absent from climate budgets. The exposed sediments turned a former carbon sink into a major emitter across Central Asia. Researchers walked the dry lake bed in 2022, pulling sediment cores and measuring gas seepage. They found that half the carbon escaped within the first 15 years after each section of bed dried out. Wind also carries carbon rich dust off the surface, a pathway earlier studies mostly missed. The study estimates that protecting the remaining carbon still buried could be worth about 18 billion dollars in carbon credits. Other shrinking lakes face the same problem, including the Great Salt Lake and Lake Chad. The authors argue that reflooding the Aral Sea could lock carbon back in the sediment, but that would require governments to redirect water currently used for farming. The findings suggest that drained lake beds are a live carbon source large enough to matter in national emissions inventories.
