The human contribution and the potential consequences are considered still unproven hyperbole. The cost/benefit of doing something else is an ongoing discussion.
Climate change is denied. Human causation is denied. The damaging consequences are denied. The net benefit of mitigation is denied. All of these positions can be found from mainstream right wingers in the US.
High quality links that cast credible doubt on the cause of rising co2 ppm and its long term effects? I'll bet money you have none.
Items that have been debunked many times are obviously not high quality or credible.
P.S. I wouldn't normally be so harsh... It's just a bit crazy how many times these claims keep coming up, when the evidence and the science is so crystal clear.