On February 8th, the seminar ‘ The expedition to the Aral Sea: witnesses of a sea ‘, conducted by researcher Rafa Marcé, was organized in the Conference Hall of ICRA-CERCA. A talk that was well received by ICRA-CERCA staff and other members of the scientific community in Girona and Barcelona. In the talk, Marcé reviewed the history of the environmental disaster of the Aral Sea, considered the fourth largest lake on the planet and which has been drying up since the 1960s as a result of the large irrigation programs promoted by the Soviet Union. This has represented a catastrophe for the ecosystem and the hundreds of thousands of people who depended on the world’s most productive freshwater fishery. In this sense, the expedition to the Aral Sea that the team led by ICRA-CERCA and Rafa Marcé himself undertook in August 2022 to sample evidence of sediment and find out if the most important natural catastrophe of the 20th century also led to the release of tens of millions of tons of carbon dioxide into the atmosphere promoted by the decomposition of organic carbon accumulated in ancient sea sediments over millennia. At the seminar, Marcé detailed the goals and adventure of the research team within the framework of the Alter-C project, and also advanced some of the results that have already been able to be processed. “Our work in the Aral Sea does not only have a scientific side: if we demonstrate that the drying of the lake has consequences in terms of carbon emissions in Central Asia, we would begin to assess whether the savings in carbon emissions that we would have if the waters returned to the sea, could be considered an option to mitigate climate change”, says Rafa Marcé.