The Substitute 5

Which is not to say excess carbon dioxide is totally fine. We can't breathe it, and that same logarithmic scaling will work against us if we try to reverse the process (we'll have to remove a shitton before we see a positive change). But it isn't the only player. Policies meant to retard or reverse global warming would do well to remember methane, for instance. There are some cool things we can do to curb methane emissions: