Point 1: Scott Adams pointed out that when asked the question "how much of global warming is caused by humans, and how much is natural" in debates and televised interviews, no scientist had an answer.
The answer is 50-70% according to this latest research.
Don't confuse the effects on Arctic ice with global warming. This research is saying that 50-70% of the ice melt is caused by the temperature increase from global warming. Our current best estimate is that 100% of global warming is caused by human activity.