The earth is heavily polluted , no question about that. So we have to find a solution.
Maybe clouds could be a solution , because in clouds there lives a lot of bacteria and algae and if we could stimulate the growth of algae in clouds , more CO2 would be processed by the algae into O2.
Another solution could be a ‘homemade’ cloud consisting of a plate on which algae can grow attached to drones or a hot air balloon that can bring the plate to a certain altitude. The algae would survive because it gets H2O from passing by clouds and it would take the CO2 from the polluted air and trasnfer it into O2.
Also another solutions could be a genetically modified algae that uses plastic as a nutrient and converts plastic or CO2 in a less harmful or easier collectable substance.