Honestly, it's probably a mixture of both.
I understand that you're trying to sound "reasonable", possibly with the goal of being able to "negotiate" or "work with" climate change advocates. Unfortunately, that hope is doomed to failure, because it's based on false premises. For example:
1. Reductio ad absurdum - whatever "mixture" the human component of any change might be, it's so statistically small that it's irrelevant. "Science" is irrelevant - their arguments are not based in science (only junk science-the true scientific method is never employed by advocates) This premise is basically a joke.
2. Climate change is NOT the real issue (basic Alinsky - with the left, the issue is never the issue). The real issue is setting up a global mechanism for massive wealth redistribution and control, of wealth, resources and people.
Yes, and I've stated this exact point many times. I just believe conservatives have always looked foolish with their denials that climate change occurs. We really need to move the talking points to: "Climate change? So what? I'm not going to live in the Stone Age over it and we're not going to transfer a trillion dollars to Africa over it either."
As long as the Left's only "solution" to climate change involve hobbling the U.S. economy while giving China and India a pass combined with buying "carbon credits" from poor African nations for trillions of dollars, there's nothing to negotiate or find any middle ground over.
This doesn't mean the conservatives should continue to deny there is any climate change taking place. Doing so has always made our side look foolish while giving liberals the "good guy" hat over stewardship of the environment. Accepting that climate change is real will free us up to hammer the left's horrible "solutions" for fixing it.