As part of Earthstock, a screening of the documentary “Merchants of Doubt” at 7 p.m. April 7 at the Mary Riepma Ross Theater. The film that explores the political and media-caused deception that creates climate change doubt in America.

Filmmaker Robert Kenner uncovers the secrets of people in the media who present themselves as scientific authorities, but have the contrary aim of spreading maximum confusion about well-studied public threats ranging from toxic chemicals to pharmaceuticals to climate change.

The screening is free and open to the public. A short discussion will follow the documentary.

The documentary is part of Earthstock, a month-long celebration of the Earth featuring diverse programming throughout the month of April.