Liquid trees, and cleaner air

Scientists in Serbia have been rolling out ‘liquid trees’, tanks of water and micro-algae that are designed to capture CO2 from city air.

The tanks use the same process that trees and plants do to harvest energy from sunlight using chlorophyll, to turn CO2 into oxygen - photosynthesis. The tanks can effectively replace two 10-year old trees, and are between 10 to 50 times faster at removing CO2 from the air. 

We like trees, but could this tank full of algae help clean up the planet?