You know, that article in Real Climate deflects the question in a really bad way. It argues

The reality, as we've often remarked here before, is that absolute statements of neither sort are scientifically defensible. Meteorological anomalies cannot be purely attributed to deterministic factors, let alone any one specific such factor (e.g. either global warming or a hypothetical long-term climate oscillation).

My problem with the article is that it basically uses the fact that this is all about statistics to say that you can't say for certain either way, so stop asking and let us get along with our climate science. You can qualify it as much as you want and talk about prior beliefs and model dependence, but there has to be a statistically sound way (with confidence levels and such) of answering the question "is this caused by anthropogenic forcing"?

"It's the statue, man, The Statue."