Shrinking Great Salt Lake could become a major greenhouse gas problem

Famous Utah lake has lost 73% of its water, and dried areas have released 4.1m tons of carbon dioxide, studies show

https://www.theguardian.com/us-news/article/2024/aug/02/great-salt-lake-shrinking-greenhouse-gas-emissions

For years, scientists and environmental leaders have been raising alarm that the Great Salt Lake is headed toward a catastrophic decline. Now, new research points to the lake’s desiccating shores also becoming an increasingly significant source of greenhouse gas emissions. Scientists have calculated that dried out portions of the lakebed released about 4.1m tons of carbon dioxide and other greenhouse gases in 2020, based on samples collected over seven months that year.

Last year, environmental and community groups sued Utah officials over failures to save the famous lake from irreversible collapse. In recent decades, as more and more water has been diverted away from the lake to irrigate farmland, feed industry and water lawns, a report last year estimated that the lake had lost 73% of its water and 60% of its surface area. Its decline was accelerated by global heating and a mega-drought in the US south-west.

The declining lake has exposed a dusty lakebed laced with arsenic, mercury, lead and other toxic substances that threaten to increase rates of respiratory conditions, heart and lung disease and cancers. As its volume shrinks, the lake is also becoming saltier and uninhabitable to native flies and brine shrimp. Eventually, scientists have warned that it may be unable to support the 10 million migratory birds and wildlife that frequent it.

Other research has documented emissions from other saline lakes, including the Aral Sea in central Asia, though more research is needed to fully understand the extent. Both saline and freshwater lakes can act as carbon sinks, he noted – in some cases locking up huge amounts of carbon in their sediments. But as the climate crisis hastens the decline of these lakes, they could begin unleashing large amounts of carbon dioxide that in turn could exacerbate global heating, creating a vicious feedback loop.