We are back with a young student with a remarkable idea when it comes to cleaning up the world's oceans. Say hello now to science star Tanya das. Reporter: We use it every day and when we're done, most of us just toss it in the trash and don't even think twice about it. The lifespan of plastic inside our homes is short, but it can spend hundreds of years existing in the environment. Every year 8 million tons of plastic waste escapes into our oceans. 17-year-old Tanya das wants to change that. Tanya has been tackling plastic pollution by building underwater robotics and teaching her peers how to do it. All the problems that humans cause, this is so preventable if only people know about it. Reporter: As early as middle school Tanya was organizing assemblies and teaching kids about public mindness. Kids have the most pliable mindsets. When you teach a kid plastic is bad, Luke out for it. They start to make the connection immediately. Reporter: Her nonprofit motion for the ocean piloted underwater robots in India last year. The India workshop, it was a really rural village and they had a river behind their school. That's where we piloted the robots. The kids were removing bigger floating debris like water bottles and bags from the rivers. Reporter: Tanya is looking forward to this year's climate summit. I would like to see more legislation conserving blue carbon ecosystems, and a national plastic ban. Reporter: She hopes her work will empower other people to find their voice and take a stand. The biggest barriers to making change is people don't think they can make a change. If we can just change that mindset, everybody would be so much more outspoken about what they're passionate about. I'm so glad we're highlighting these young folks who are changing the world. And inspiring so many. When we come back on "Gma3"