Megwyn, yeah I think it does matter that we know what is causing it, if we don't know we can't fix it (if it's fixable).
Does it matter if it is only due to natural causes, or if it really is human impact? If we can reduce our impact, then should we not find a way?
What is the worst thing that would happen if they were wrong, and we put systems in place to lesson human impact on the environment?
What is the worst thing that could happen if we are a major contributor to the problem and we don't?
Why, after so many years of debate (I don't know how long this debate has been boiling, but it seems like around 2 decades), are we still arguing about cause?
Put that enormous human energy and ingenuity into preventative and supportive measures rather than destructive arguments.
Ego has no place when an entire planetary ecosystem is at stake
Or do we just wait for the Vogans (or some other intergalactic species that may or may not exist) to vaporise us all.