a) True. The planet has been warmer and cooler than it is now.
b) Humans change a lot of things. SOME of the change is caused by humans. Nobody has even come close to defining how much change is human caused; all such models have failed clearly indicating that AGW (not Climate Change) is pure speculation even if it is also scientific consensus (which by definition, isn't science)
c) Key word "Might". No such proof exists, and all models that predicted horrible events have failed.
d) Key word "Could". No such proof exists, and all models that predicted horrible events have failed.
e) Key word "Might". No such proof exists, and all models that predicted horrible events have failed.
f) Key phrase, "administered effectively by government(s)", an assumption that I reject completely as irresponsible.
Basically, you have a bunch of unproven assumptions and, worst of all, faith in government. Fix the assumptions (and "consensus" isn't facts), and replace your faith in government with healthy scientific skepticism and you might convince people like me.