By studying fossils from ancient aquatic plants, Northwestern University and University of Wyoming (UW) researchers are gaining a better understanding of how methane produced in Arctic lakes might affect — and be affected by — climate change.
In a new study, the researchers examined the waxy coatings of leaves preserved as organic molecules within sediment from the early-to-middle Holocene, a period of intense warming that occurred due to slow changes in Earth’s orbit 11,700 to 4,200 years ago. These wax biomarkers — which were once a part of common aquatic brown mosses — were preserved in sediment buried beneath four lakes in Greenland.
Monitoring changes in methane levels
By studying these biomarkers, the researchers discovered that past warming during the middle Holocene caused lakes across a wide range of Greenland’s climates to generate methane. Because methane is a more potent greenhouse gas than carbon dioxide, any changes in methane production with warming are important to understand.