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.
"These data show increased periods of methane cycling during past warm periods," added Magdalena Osburn, the study's senior author."Living on a warming planet, we can look to these signs from the past to help predict our future. We suspect this process is going to become more and more important in the future of these lakes."
To explore these dynamics, the researchers produced new data at two lakes and reviewed published data from two additional lakes on Greenland .