There are four links in that chain, and all must be solid for the man-made global warming issue to be valid. Nothing else matters.

1. Has CO₂ levels in the Earth's atmosphere been increasing over the past century? Scientific reports indicate that is the case.
2. Is CO₂ a gas that causes heat to be retained in an atmosphere, thus making it a "greenhouse gas"? Scientific reports indicate that is the case.
3. Does human industrial and transportative processes produce vast quantities of CO₂ in the Earth's atmosphere? Scientific reports indicate that is the case.
4. Has the average global temperature actually increased over the past few decades? Scientific reports indicate that is the case.

Those who throw around issues like nuclear power, questionable reports of exceptional weather, recent solar output, or natural climate changes in ancient or prehistoric times, only seek to cloud the issue. Unless and until you deal directly with the four central issues at the heart of the global warming issue, you have no real case.
 

The chain of reason remains unbroken.