Okay, we have a basic problem of logic here. When someone asserts something, it is up to that person to prove it; it is not automatically assumed true in the absence of such proof. In this case, the assertion of man-made global warming is the basic hypothesis. We've been hearing about it for two decades so far, and nothing even close to approaching proof has been discovered, despite many millions upon millions invested in trying to do so.
I don't need to be a specialist to follow Logic 101. The burden of proof is on the asserter. Negatives cannot be proven. No argument can change these facts.
The burden exists on the other side to disprove the assertion rather than just ignore it, especially if they consider it important. That's the scientific method. Scientists have presented data on changing ocean currents, on CO2 levels, on changes in animal migrations and plankton levels, and so forth. Those who deny global warming aren't presenting data to rebut these claims, or aren't doing so in enough numbers to convincingly put the issue to rest. The least we can say is that the jury is still out.