Is it worth spending hundreds of billions of dollars to fight global warming?

We have global warming whether it is man caused or not if it is man made we have a small window to stop it. If it is from natural causes if man cleans up his act we will have a cleaner planet to live on as the warming progresses. Either way what we are doing now is wrong and we need to move to have options that don't pollute. We don't allow litter or pouring polluting chemicals in our waterways why do we allow polluting the air. Is it because most of the time we can't see it?