New research shows the Aral Sea has emitted 748 million metric tons of carbon dioxide since 1960 as it dried into a salty plain the size of Ireland. The study, published in the journal Science, reveals the former lake has become a major source of greenhouse gases.
The Aral Sea sits between Kazakhstan and Uzbekistan. It was once the fourth-largest inland body of water on Earth before irrigation for cotton crops reduced it over the past 60 years.
Rafael Marcé of the Centre for Advanced Studies in Blanes led the research. His team sampled sediment along the lakebed's drying timeline and found that half the carbon dioxide escaped in the first 15 years after exposure. Wind-blown dust accounted for nearly one-fifth of emissions.
The study estimates another 605 million metric tons remain stored in the lakebed. Marcé said protecting this carbon could create opportunities through carbon credit programs.
Other shrinking lakes face similar risks. These include the Caspian Sea, Lake Chad, and Utah's Great Salt Lake.