According to GreenUpgrader, synthetic trees developed by Dr. Klaus Lackner could be an environmental boon built to scrub the atmosphere of our CO2 excesses:

“The idea is that air would flow through the vanes of these structures. Flowing through sodium hydroxide (NaOH) which is inside the synthetic tree CO2 would chemically react to create sodium carbonate liquid which condenses and collects at the bottom of the synthetic tree.”