Sorry, I missed these earlier.
On "How Red Are Your Proxies", the best technical response is already given by Professor Koutsoyiannis on the thread. However, this debate is not easy to follow unless you are familiar with the territory. I can try and explain the problems with the Ritson method, although I'm not sure how to pitch it technically - it depends on how familiar you are with the topic.
Autocorrelation in time series is when a point in a series has some dependency on the previous point (or points). The presence of autocorrelation in a time series has huge implications for analysis performed on that data set. To deal with it, we impose a model which defines the autocorrelation. The simplest of these is Markovian dependency, or
autoregressive model, commonly referred to as AR(1). Prof Ritson's estimator works well (as do other classical estimators) against this type of model.
The problem with Prof Ritson's method is that it collapses if the underlying time series has a different type of autocorrelation. The Hurst phenomenon is one example, but even this is unnecessary - the Ritson estimator fails spectacularly against other types of Markovian models, such as an
ARMA model. The ARMA model is like the simple autoregressive model, but adds a moving average component. This model is useful and can be used to accurately represent simple AR(1) models with uncorrelated noise added - such as noise added during the measurement process. Estimating underlying values of ARMA processes is more challenging, classical estimators do an okay job but the Ritson estimator produces estimates which are very wide of the mark.
This means the Ritson estimator is only valid to use if you are very confident indeed that there is no risk of the data set being anything other than a simple AR type. Of course, there is no evidence presented for this, and the assumption is quite obviously dangerous to make. Koutsoyiannis outlines the technical reason for the problem with the estimator in the thread (comments 35 on). A few days after this, others found the problems through Monte Carlo analysis and the thread had comments shut off rather promptly.
As for the second article, Prof Koutsoyiannis chose not to respond on realclimate, but instead at ClimateAudit. I would encourage you to read his response
here. The issues addressed here are of a less technical nature, and probably do not require any additional commentary from me