By far the easiest solution to climate change is not emitting greenhouse gasses in the first place.
Except that has already failed. We already have sent enough CO₂ into the atmosphere that global warming is already here. You can no longer solve the problem by just stopping greenhouse gas emissions. All serious solutions now involve some form of geoengineering. Either block out the sun or pull CO₂ out of the air, those are the only possible options.