Companies can make a large impact on the environment by focusing their efforts on sustainable practices, M. Sanjayan, a conservation scientist and the host of the PBS series "Earth: A New Wild," told a packed Geological Lecture Hall on Thursday night.

The lecture, titled “How Nature Can Save Us,” focused on how important nature is to humans. It was organized by the Harvard Museum of Natural History and the Harvard College Conservation Society in their first collaboration.

Sanjayan, who is also executive vice president of Conservation International, said his group has been working with Starbucks for the past 15 years in an effort to sustainably source 100 percent of the company’s coffee.

Fifteen years ago when Conservation International first started working with Starbucks, only about 10 percent of the company's entire supply chain was sustainably produced. Now, Sanjayan said, that number is 100 percent.

“For them, sustainability equals availability. In a world of seven billion people, if you want to be a global company, you really better think about where your coffee comes from, you better think about where your water comes from, you better think about where the pollution goes,” Sanjayan said. “Because eventually you’re going to get caught up in it.”

Later in his speech, Sanjayan said diversity is important in the field of conservation in order to provide role models to the next generation of environmentalists.

“The messenger is also as important as the message. And sometimes in science and in conservation for sure, we forget. And we forget that much to our peril,” he said.

After the event, Sanjayan said his most important piece of advice to young people hoping to get involved in conservation would be to act now.

“Don’t sit this one out. You’ve got 20 years to make a difference,” he said. “Make it count.”

During the event, Sanjayan said, “Your generation is an amazing generation. Because you guys have the chance to know what’s coming in the future and still have time to do something about it.”

Attendees said they enjoyed the presentation. “I thought it was fantastic,” said Paula S. Tallman, a post doctoral fellow at the Field Museum of Natural History in Chicago.