What safe (unharmable gas can combine with co2 (carbondioxide) to form a green product?

Question

What safe (unharmable gas can combine with co2 (carbondioxide) to form a green product?

Answer 1

Nothing really.

CO2 is chemically stable in our atmosphere, so it won't just react with some miracle substance.

The best way to get rid of CO2, and in the process create O2 (oxygen) is photosynthesis, the biochemical process by which plants turn carbon dioxide, water, and sunlight into oxygen and a sugar (which it then uses for energy).

Trees are the best due to their size and resilience, but any plant is a good thing.

Answer 2

Plant a tree, they convert CO2 to oxygen.