Climate change seems to get a 3 position argument:
1. It's real and humanity has contributed to it.
2. It's real and entirely natural.
3. It's not real.
Can someone link me to studies that support #3? Everything that I have seen (in my somewhat limited research) indicates that >90% of climate scientists say it's happening. I know that climate science has a lot of assumptions and competing models, but it's different from "the weatherman is always wrong," which is an argument I hear more frequently than you'd expect.
I think that #1 and #2 are the only reasonable positions right now, with the science that we have. Do we have a concrete way to determine whether #1 or #2 is more true? Does it actually matter what's causing it? Will anything we do at this point make a difference?
I don't think anyone actually believes #3. At least, anyone of any import. I think the competing ideas are 1 and 2. There isn't really a debate over whether or not the climate is changing. It is.
And, in my non climate scientific expertise (read as none), it shouldn't be that hard to determine humans are having a significant effect. As more nations become industrialized, more CO2 is being emitted into the atmosphere, right? Shouldn't temperatures be rising faster than they were before? Even if we only take data from the time we have an accurate way of measuring it (18th century), shouldn't the furthering industrialization of places, as well as increased population, show some increasing effect?
I haven't done a ton of research, but the prediction models touted around seem always be wrong.
And, could it be that we haven't (we as in the climate of the Earth) not reached the equilibrium surface temperature yet? Couldn't that temperature be something bad for humans? And we are simply clinging to the 200 years of recorded climate data and seeing it as normal? Sure, it might suck for us if the temperatures continue to rise to a level that disrupts out current ecosystem, but the Earth doesn't give a shit.