One evening in late 1997, 11-year-old Claire Lackner walked into her dad’s study looking for an idea for an experiment for her sixth-grade science class. Her dad, Klaus Lackner, happened to be a physicist working on nuclear fusion at Los Alamos National Laboratory. He’d grown skeptical that fusion could replace dirty fuels and had started thinking about how to take greenhouse gases out of the atmosphere instead. So he suggested Claire try to capture carbon dioxide from air. She bought an aquarium pump and bubbled air through a test tube of sodium carbonate, a base, which bonded with the acidic CO₂ in the airstream, removing about 10 percent of it overnight. Claire won a prize at the county science fair, and her father later wrote a paper arguing that extracting CO₂ from air “has a reasonable probability of success” at reducing global warming.

Scientists had known since the 1950s how to strip CO₂ from the air inside submarines and spaceships to keep the crews from suffocating. But Lackner’s paper was the first to argue that we could strip it from the atmosphere to keep Spaceship Earth livable. Claire’s experiment, he says, showed “it’s not all that hard.”

Read on at Scientific American