IPCC – Full Speed Ahead
Posted by Jeff Id on December 14, 2012
Thanks to some very hard working bloggers and readers who care at WUWT, the IPCC second order draft has been released. Steig 09 appears to be much less prominently referenced in the second order draft than in the zero order which is still too often. I take it as an indication that some people have actually figured out that S09 was not in any way accurate. Still, in the Second order draft, the IPCC is reporting warming values so high that they are not supported by either the S09 paper or the O’Donnell correction.
From Chapter 5 – Information from Paleoclimate Archives:
Currently there is no compelling observational evidence for a robust CO2-induced polar amplification in
Antarctica. Whereas the Antarctic Peninsula is experiencing one of the strongest regional warming trends
(0.5°C decade–1 over the past 50 years), almost twice that of the global mean temperature, zonal mean
Antarctic surface warming has been modest at 0.1°C per decade over the same time period (O’Donnell et al.,
2010; Steig et al., 2009). West Antarctic Ice Sheet (WAIS) Divide borehole measurements indicate warming
of 0.8°C per decade during the last two decades (Orsi et al., 2012), but it remains unclear if this trend
represents long term polar amplification, or is within the range of regional decadal variability (see also AR5
Chapter 2). Polar amplification in the Southern Ocean and Antarctica is virtually absent in the transient
CMIP5 RCP4.5 future simulations (see Chapter 12).
Below are the actual numbers from Steig (far right column) and O’Donnell’s two methods E-W and RLS in the center and left column. At 0.1C/decade for the continent, the IPCC is reporting approximately 2X the actual Antarctic trend measured by the skeptic-leaning “thermometers”. It is also right at the farthest edge of the 95% margin of error threshold for the continental Eigenweighted calculation (0.4+/- 0.06). The peninsula was reported too low by S09 as we have long discussed, but in O10 some regions do reach 0.5C/decade (again according to the thermomters) but the peninsula regional average is only 0.35 +/- 0.11. Therefore the IPCC reporting 0.5C/Decade for the peninsula is completely outside the margin of error for both papers. Not surprisingly to those of us who spend time reading climate science and IPCC UN politics, the reported values fail in the alarmist direction.
|Region||RLS C/Dec||E-W C/Dec||S09 C/Dec|
|Continent||0.06 ± 0.08||0.04 ± 0.06||0.12 ± 0.09|
|East Antarctica||0.03 ± 0.09||0.02 ± 0.07||0.10 ± 0.10|
|West Antarctica||0.10 ± 0.09||0.06 ± 0.07||0.20 ± 0.09|
|Peninsula||0.35 ± 0.11||0.32 ± 0.09||0.13 ± 0.05|
It is really unfortunate that they have chosen to report the Orsi borehole mathmagic as though it were a thermometer, but this is the paleoscience chapter so they need to put something in. That paper claimed a 0.8C/decade warming in the last two decades. Readers will recall that this was the paper which Steig famously claimed “proved” O’Donnell was wrong. Besides the whole field of borehole thermometery being ridiculous, it seems to me that the 0.8C/decade value is completely outside the realm of any possibility. I write that because it is 13 times the continental average and were the trend real, nearby thermometers would have obviously detected it.
I don’t know folks, it doesn’t look like the world of Climate ever changes. Maybe they will get it right in a few more drafts.