Khandro;
I'm not sure who is saying that human activity isn't responsible for SOME changes in the climate, how could it not be? but that is not to say it is ENTIRELY responsible."
Well that's a start. If human activity is partially responsible, then humans can modify their activity to help reduce climate change. It might be difficult, but it's something we can work at. If you're overweight, or addicted to tobacco or whatever, then you can either fight it or give in, and you might be able to save yourself from personal harm. In the case of climate change, it affects everybody on the planet, not just you, so you should really do all you can to fight it.