”Do the Math,” a film featuring the 350.org Bill McKibben speaking tour, will be shown Saturday, July 27, at 10 a.m. at Thomaston Public Library in the Thomaston Academy building on Main Street/Route 1. The screening is scheduled during the weekly Farmer’s Market.

The documentary explains the scientific understanding of climate change with three numbers: the expected rise of earth temperature; the amount of carbon in the atmosphere; and the amount of explored fossil fuels and the expected effect of their extraction. Extended scenes were filmed in Maine, featuring local 350.org activists and Stephen Mulkey, president of Unity College.

The free screening is sponsored by 350Maine.org and the Thomaston Public Library.

Courier Publications’ A&E Editor Dagney C. Ernest can be reached at (207) 594-4401, ext. 115 or dernest@courierpublicationsllc.com.