Dr. Stephen Norton will discuss the history of air pollution in Maine at the Belfast Free Library, 106 High St., Wednesday, March 7, at 6:30 p.m.

Humans have been able to accurately characterize the chemical climate of Earth for only about 50 years. To study pollution prior to the 1950s, scientists study the archives of pollution that are stored in soils, tree cores, museum collections of vegetation, ice cores from high elevation and/or high latitude, lake sediments, and peat accumulations in bogs.

Sponsored by Friends of Sears Island, Norton's presentation will focus on what soil surveys, lake and peat sediments can reveal, and if time allows, a few comments on the other archives.

Norton is a professor emeritus in the University of Maine's School of Earth and Climate Sciences. He graduated from Princeton and Harvard University, earning his Ph.D. in 1967. He joined the Department of Geology faculty at the University of Maine in 1968, where he taught and did research until his retirement in 2008. His research is in the field of aquatic geochemistry.

This program is free and open to the public. To learn more about Friends of Sears Island, visit friendsofsearsisland.org. For program updates in the event of inclement weather, visit facebook.com/friendsofsearsisland or call 975-3878.