Direct Air Capture
Some scientists want to clean the planet with industrial-sized air filters designed specifically to remove carbon dioxide from the atmosphere. In this method, air is sucked into giant turbines, then is passed through filters that capture the C02. The cleaned air is then released back into the atmosphere. The filters are heated to clean them so they can be reused and the cycle can be repeated.
A Zurich-based company called Climeworks unleashed these fans in May of 2017. Climeworks says it is the world's first "commercial carbon dioxide capture plant," though the concept itself is not new. The strategy, called direct air capture, is also underway at companies in Canada, the United States and the Netherlands. However, Climeworks says 18 of its CO2 collectors already have removed 900 tons (914 metric tons) of carbon dioxide at its first plant in Switzerland.
This might sound extreme, but direct air capture is one of the safest methods of geoengineering because its lacks relatively drastic side effects. Still, several scientists caution that it can't keep up with current rates of carbon dioxide emissions.