UPDATE: McIntyre discovers a serious flaw right away, more upside down Mann world – he writes:
In keeping with the total and complete stubbornness of the paleoclimate community, they use the most famous series of Mann et al 2008: the contaminated Korttajarvi sediments, the problems with which are well known in skeptic blogs and which were reported in a comment at PNAS by Ross and I at the time. The original author, Mia Tiljander, warned against use of the modern portion of this data, as the sediments had been contaminated by modern bridgebuilding and farming. Although the defects of this series as a proxy are well known to readers of “skeptical” blogs, peer reviewers at Nature were obviously untroubled by the inclusion of this proxy in a temperature reconstruction.
‘Charles the Moderator’ writes to inform us that there’s another multiproxy study published, with flat blade and a somewhat limp hockey stick combined with that “unprecedented” claim that has become almost a red flag for bad proxy studies when they are that certain. From the SI PDF file, it looks like it is another splicing study, where they have added CRU data to the paleo reconstruction using tree ring, ice core, and varve data.
I have to wonder though, about the insensitivity of the proxies in the past, that blade seems pretty flat.
Of course it is paywalled, so we can’t examine it in detail yet, but that hasn’t stopped the MSM from ramping up science by press release stories already. The small figure are from the Nature page on the paper.
Recent temperature extremes at high northern latitudes unprecedented in the past 600 years
- Nature 496, 201–205 (11 April 2013) doi:10.1038/nature11969Received 01 September 2012 Accepted 29 January 2013 Published online 10 April 2013
Recently observed extreme temperatures at high northern latitudes1, 2, 3, 4, 5, 6, 7 are rare by definition, making the longer time span afforded by climate proxies important for assessing how the frequency of such extremes may be changing. Previous reconstructions of past temperature variability have demonstrated that recent warmth is anomalous relative to preceding centuries2, 8, 9 or millennia10, but extreme events can be more thoroughly evaluated using a spatially resolved approach that provides an ensemble of possible temperature histories11, 12. Here, using a hierarchical Bayesian analysis13, 14 of instrumental, tree-ring, ice-core and lake-sediment records, we show that the magnitude and frequency of recent warm temperature extremes at high northern latitudes are unprecedented in the past 600 years. The summers of 2005, 2007, 2010 and 2011 were warmer than those of all prior years back to 1400 (probability P > 0.95), in terms of the spatial average. The summer of 2010 was the warmest in the previous 600 years in western Russia (P > 0.99) and probably the warmest in western Greenland and the Canadian Arctic as well (P > 0.90). These and other recent extremes greatly exceed those expected from a stationary climate, but can be understood as resulting from constant space–time variability about an increased mean temperature.
Figure 1: Time series of temperature anomalies and centennial slopes.
a, Average land temperature between 45° N and 85° N (black), 90% pointwise (blue shading) and pathwise (grey) credible intervals20 (see Methods); the unweighted average of all available instrumental observations (magenta)
Figure 2: Warm and cold extremes.
a, The proportion of draws (see Methods) for which 2003 and 2010 were warmest, and for which the warmest year fell in the 1990s and 2000s. White shading indicates zero. b, The fraction of all locations for which years were warmest
Figure 3: Histograms of temperature anomalies and instrumental maxima for the period 1992–2011.
a, Histogram of temperature anomalies across locations, ensemble members and years for the interval 1992–2011 (blue); the simulated distribution of temperature anomalies, using median parameter values fitted over 1400–2011 (black)
There are a number of SI files though:
- Supplementary Information (8.3 MB)
- This file contains Supplementary Figures 1-53 with legends, Supplementary Tables 1-6, Supplementary Discussion and additional references.
- Supplementary Data 1 (630 KB)
- This file contains the instrumental data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
- Supplementary Data 2 (716 KB)
- This file contains the tree ring density data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
- Supplementary Data 3 (218 KB)
- This file contains the varve data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
- Supplementary Data 4 (262 KB)
- This file contains the ice core data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.We are unable to host the Supplementary Code and Model output files and these can be found at the following link:- ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tingley2013/tingley2013.zipThese files contain a number of model outputs, available, where possible, in both Matlab and .txt formats. Also included are a number of Matlab scripts that manipulate the model output to reproduce the main features of the analysis, and a short ReadMe document that describes the data and files.