“Let me tell you what it was like.”

With these words, an aging man opens Ken Burns’ new documentary “The Dust Bowl” and ushers viewers into his memory of the environmental collapse that destroyed farming in the Midwest during the Great Depression of the 1930s. The film shows how drought, overfarming and poor practices triggered the worst man-made ecological disaster in United States history. Burns described his film as a cautionary tale for today, given the effects of climate change.

Burns has been an award-winning filmmaker for more than three decades. He presented the introduction and several clips from “The Dust Bowl” to an overflow crowd at Boylston Hall on Wednesday afternoon. The two-part documentary will premiere November 18 on PBS.

Burns said he wanted his film to go beyond the common image of the Dust Bowl that stems from such popular portrayals as John Steinbeck’s “The Grapes of Wrath” and Dorothea Lange’s famous photo of a migrant mother.

“I have always been compelled mostly by the idea of telling stories,” Burns said.

“The backbone of our film is the testimony of more than two dozen of the survivors,” he added.

His film incorporates the personal narratives of 26 such Dust Bowl survivors, whom Burns said he located through an “incredibly determined and detailed search.”

About half of the interviewees have since passed away.

Though the speakers are in their 80s and 90s, Burns asked the audience to imagine them as the children and teenagers they were when faced with the horrific conditions that destroyed land and lives, and sparked one of the largest migrations in American history.  Many of those fleeing the Dust Bowl in Kansas and Oklahoma settled in California.

After the screening, Burns fielded questions from the audience on “The Dust Bowl,” his past films, and his creative method.  In prior films, Burns’s topics ranged from the Civil War to jazz to baseball.

Burns said he did not often struggle from having too much or too little material to include. “It’s more the mastery of narrative which is so complicated,” he said.

Burns also said that he believes in the future of long-form documentaries, even in a society of instant gratification, due in part to the immortality of stories told on film.

“Memory – the DNA of history – is not something that is old and dusty,” he said.

Honor R. Wilkinson ’14, who has an interest in documentary film, said, “It was amazing to listen to him speak about the thought process behind his work.”

Burns said he is working on several films and has definitive plans to release documentaries through at least 2019.

“If I were given a thousand years to live,” he said, “I wouldn’t run out of topics in American history.”