Here’s one way the climate change sceptical argument works:
Premise 1: Science gives us proof and certainty.
Premise 2: Climate change is not proven or certain.
Conclusion: Climate change is not science.
This argument is good in one sense: it is logically coherent. So if you want to challenge the conclusion you need to challenge one or other premise.
But it would be a mistake to challenge Premise 2 by arguing the unwinnable case that climate science is proven to be true in some absolute sense. In fact, the problem is with Premise 1, as explained above: science does not offer the sort of proof or certainty that the sceptic demands.
Careful science speaks of degrees of confidence.
And while the evidence does not amount to certain proof, it is beyond reasonable doubt and leaves no room for delay.