[asgard1024]

In the same article, they explicitly mention that the study is not based on tree ring proxies. In fact, all the global reconstructions are based on many different proxies.

I also think you misrepresent the 2nd article. The question is what and on what time scale are you trying to predict. I believe they are talking about more precision more short-term models. Just like we can predict winter and not predict weather, we can predict warming due to human forcing, but not the specific details.

In the end, however, it's completely irrelevant to AGW if there was a higher temperature in the past or not. The theory of AGW doesn't stand just on that argument (nor any other single argument, for that matter).

[thaumasiotes]

Without trying to say too much, one big reason we can predict winter is that we've had hundreds of thousands of years of experience with it.