Yet we cant seem to learn that you cant divine specific environmental effects like temperature from tree rings. - - - Updated - - - No its quasiperiodic because it does not always have two phases which is easily proven.
So you're an expert on dendroclimatology now? Quasiperiodic is nothing more than an oscillating function with an irregular period. And I eagerly await your proof that the Multivariate ENSO Index can have a value other than positive or negative.
That is the thing there is no experts on dendroclimatology. Actual tree experts have clear that there is no way to divine temperature or any one signal from tree rings. Tree growth is influenced from dozens of factors. Simply put actual experts on trees don't know everything about tree growth. Dendroclimatists have no expertise what so ever in actual botany or forestry. They are frauds selling people a bill of goods. A good example of the problem with tree rings is best exemplified by this picture of Dr. Mann himself. The ring growth is not uniform which is normal for tree growth. Depending on the angle you take the core you will get vastly different results from the same tree. If you core from the left you get no midieval warm period and if you core from the right you get a strong midieval warm period. These people are frauds. Dendroclimatology itself is a fraud. I didn't say it can be other than positive or negative. I said it isn't oscillatory that is not the same thing. Not every positive el nino is followed by a negative la nina and not every negative la nina is preceded by a positive el nino.
The problem with dendroclimatology is the apparent lack of continuity between actual temperature and tree rings, the difference in tree rings in similar locations, etc. "You can get anything you want at hockey sticks restaurant."
Quite right, if you take 100 samples and look for those that correlate with temperature and find 10 that doesn't mean that the 10 are actual temperature proxies. They could be correlating on pure chance. Or they could represent a temperature signal for the calibration period you are using. However, that doesn't mean that hey represent a temperature signal for all time periods. Just becaus it correlates in the presnet doens't mean it correlated in the distant past. After all 90% of your samples don't correlate in the calibration period that means that there is a good chance that the ones that do wont in other time periods. Say you have one tree ring that has thick rings in the 20th century because it was warmer. Okay that might be an actual temperature signal. However, that same ring could have periods in the past where it was warm but other factors like precipitation, and or pests limited its growth. When you have a proxy that can be influenced by so many factors you need way more than a single calibration period to know if you have a good signal or not.
