PITTSFIELD — Of all the things they could be doing on a Saturday, more than a dozen students, from elementary through college, donated their time as presenters at the Berkshire Earth Expo, held at the Boys & Girls Club of the Berkshires.

Earlier this school year, Living the Change Berkshires, organizing agency for the expo, put out a "Cooler Communities Challenge" to area schools for students to develop projects relative to climate change, composting, recycling, sustainable agriculture, plastics, public transportation, pollinator gardens, and more for the event.

Saturday's resulting presentations took the form of display boards, slideshows, short films, art work, live science projects and demonstrations and more.

At Darrow School in neighboring New Lebanon, N.Y., environmental educator Leah Penniman teaches students about sustainability and the environment. First-year students have all been learning about sustainable agriculture and growing practices at the Homer C. Thompson Vegetable Research Farm of Cornell University. They also shared some of their concerns about food deserts and global warming with Congressman Antonio Delgado, who lives in and represents the district where Darrow School is located.

During the expo Darrow students shared their research on five-year farming plans detailing crop rotation, soil health and management and organic farming practices.

"I hope this invites people to take a second and look and think of a different way of doing something," said Shante Melville, who made a poster with classmates Haven Westcott and Alex Rossen.

Melville, who grew up in California, has concerns about the depletion of water sources, while Westcott, who lived in Otis, has concerns about the long-term effects of a gas pipeline recently built in his former backyard.

Asked about whose responsibility it is to watch over these issues, Westcott said, "It's everyone."

"We have to lobby the legislatures to give them the extra push for policies so we can make the world better," he said.

At a neighboring Darrow display, Matthew Lucien said he's changed a lot of his lifestyle habits since taking Penniman's environmental science classes and seeing changes on his own school campus.

"I used to just throw all my trash away. Now, I take the time to separate and recycle my water and Gatorade bottles," he said. "I'd be ousted [by my classmates] if I didn't, so why not try?"

He also says he prefers to travel by bicycle versus car when he can, to help reduce his carbon footprint.

Asked about his vision for the future, Lucien said, "I want it to be sustainable. I just want people to be considerate of each others' environment."

Taconic High School sophomores Cloey Parlapiano and Gianna Arace both agree that it's people's choices that will help change the outcome of the planet.

"Contaminating soil and water all comes back to us," said Parlapiano, who presented her research on sunscreen and how it can contaminate and contribute to the poisoning and bleaching of reef corals.

Arace used a 3D printer and biodegradable filaments to make her own alternatives to traditional plastic utensils. She was able to test and see them begin to decompose in soil after three weeks, versus the plastic ware.

But the bigger change she'd like to see is people throwing away less plastic.

"I like to go for walks but I feel like every step I take there's a plastic bottle or can on the sidewalk, even if there's a trash can five seconds away," Arace said. "There's a lot of wildlife in the Berkshires and they don't need to be eating that."

Asked to give society a letter grade for efforts to protect the environment, Arace gave a "D" while Parlapiano gave a "C minus."

A few booths down, second-year students at Great Barrington's Simon's Rock Academy shared both a poster on climate change and gave a slideshow presentation on climate change and agriculture during the Berkshire Earth Expo. Estela Quinones of New York City, Grayson Ball of Mississippi and Remy Bahr of Latvia each said it's difficult to give a global letter grade for environmental protection and progress, because people and policymakers are so ranging in their habits and priorities.

"It's really important to be educated on the issues and also the political aspect," said Quinones.

"The changes we make now will affect us a hundred years from now, in one way or another," Bahr said.

This story has been modified to clarify Remy Bahr's country of origin.