Yes, the past temperature record has to be distinguished from natural variability. That hasn't been done yet. About 4 Watt per square meter for a doubling. Remember, climate changes all the time regardless of human activity. Climate changes on the order of 1-4C would probably be distinguishable.
Local changes are much larger than global changes, and generally uncorrelated with global change.
The question is what does this lead to for policy and its evaluation. Personally, I'm uncomfortable with major policies that can't be assessed. There is an expectation of mean increase apart from patterns of variability. I mean that there won't be a criterion for establishing whether there is a problem or whether it is being mitigated. I also think that it would be worth assessing the model representation of important physical processes.