More recently two of the authors published Viau et al (2012) which surely supports the contention of this SkS OP as it kicks off its conclusions stating «The pollen -
based paleoclimate reconstructions show that warmer conditions during the MWP and cooler in the LIA were all nevertheless cooler than the 1961 — 1990 base period, and this result emerges even without comparing the results to the instrumental record.»
Not exact matches
«Our study has found evidence to the contrary, suggesting that in fact, the future long - term trend
based on
paleoclimate reconstructions is likely towards diminishing precipitation, with no relief in the form of increased Mediterranean storms, the primary source of annual precipitation to the region, in the foreseeable future.»
In Eos now... three early - career scientists report on the PAGES 2nd YSM in Goa, and discuss future directions for the
paleoclimate field, e.g. the need for network building, more quantitative proxy -
based reconstructions, fast and efficient data sharing, securing funding, and communicating results.
Paleoclimate reconstructions are an application of multivariate calibration, which provides a theoretical
basis for confidence interval calculation (e.g., refs.
The Summary for Policymakers also incorporates, for the first time, information on, inter alia,
paleoclimate reconstruction studies, geoengineering, and an emissions -
based perspective on drivers of climate change.
After discrediting the entire
basis for tree - ring
paleoclimate reconstruction, he says that the studies do not invalidate their qualitative use.
Plotted are the period and phase (of expected peak coldness) of two extraterrestrial signals (astronomical determinations of the spiral arm pattern speed and cosmic ray flux
reconstruction using Iron meteorites) and two
paleoclimate reconstruction (
based on sedimentation and geochemical records).
If you look at Mann's worldwide MWP
reconstruction publications, you will see that it is (necessarily)
based on modelling
based on scattered
paleoclimate proxies.
MM05a was critiqued by Wahl and Ammann (2006) and the Wahl et al. (2006)
based on the lack of statistical skill of their
paleoclimate temperature
reconstruction.
The many and varied shortcomings of the field of
paleoclimate proxy -
based climate
reconstruction are very worrisome, in my opinion.
Although his CV says he has a research interest in
paleoclimate reconstructions, his publishing record shows that he has not published, as opponsed to giving talks
based on the infamous report, on this subject at all.
Actual
paleoclimate reconstructions aren't exercises in mathematical interpolation but are the results of models
based on principles of physics — and thus extrapolate beyond the evidence, and if they are good models that incorporate enough of the physics, they do so skillfully.
A less satisfactory variant of RegEM has been much used by Michael Mann for
paleoclimate proxy -
based reconstructions.