Ellie Mackay devoured David Attenborough nature documentaries as a kid—and then one trip served up a hard reality: “The Galapagos are known globally for being the cradle of life on Earth,” she says. “And yet, when we reached the shorelines, they were thick with plastic, covering every part of the coast.” She knew scientists needed data to really make a difference. So she and her team at ellipsis.earth are taking to the skies—using drones and an AI-powered software platform to efficiently and accurately track plastic pollution. That info is then shared with governments and nonprofits—“so scientists can spend their time solving the problem, not wasting time figuring out what the current state is.” To date, her startup has helped lead plastic clean-up projects all over the world, from the U.K. coastline to the banks of the Ganges in India. And Mackay says she remains hopeful about the future of the planet—and encourages other young people to do the same. “Use the powers you have and c...