Global Temperature Report – Sep 14
By Paul Homewood
| RSS | UAH | HADCRUT4 | GISS | NCDC | |
| Sep 2014 | 0.21 | 0.30 | 0.59 | 0.77 | 0.72 |
| Change from last month | +0.02 | +0.10 | -0.07 | +0.07 | -0.03 |
| 12 month running average | 0.23 | 0.25 | 0.55 | 0.65 | 0.68 |
| Average 2004-13 | 0.23 | 0.19 | 0.48 | 0.58 | 0.59 |
| 12 month average – 1981-2010 Baseline | 0.13 | 0.25 | 0.26 | 0.26 | 0.26 |
Surface and satellite temperatures continue to diverge, as the graph below shows. So far this year, GISS is running 0.06C warmer than 2013. RSS and UAH both post slight increases of 0.01C.
Notes
UAH and RSS are the two satellite datasets, that measure temperatures in the lower troposphere, from the surface up to about 8000 metres. The NCDC, HADCRUT and GISS datasets measure surface temperatures.
All temperatures are presented as anomalies, i.e the difference, measured against a baseline, that is different across all four sets. (This means that the anomalies are not directly comparable between sets)
The baselines used are:
RSS – 1979-98
UAH – 1981-2010
HADCRUT – 1961-90
GISS – 1951-80
NCDC – 1901-2000
HADCRUT is maintained the UK Met Office’s Hadley Centre in conjunction with the Climatic Research Unit at the University of East Anglia.
GISS is run by the Goddard Institute for Space Studies at NASA.
NCDC is the National Climatic Data Center, part of NOAA.
UAH is the University of Alabama in Huntsville, and their dataset is part of an ongoing joint operation with NOAA and NASA.
RSS is a scientific research company, Remote Sensing Systems.
Sources
1) RSS
2) UAH
http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc_lt_5.6.txt
3) HADCRUT
4) GISS
http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt
5) NCDC
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
Note that only UAH uses 1981-2010 – this is the 30 year period (ending in a zero) accepted by the WMO as a proper reporting period. The term “normal” is used rather than 30-year average – an odd term but that is the definition. Any other baseline period has to be defended with some Ad hoc reason. Wikipedia says about Ad hoc: “It generally signifies a solution designed for a specific problem or task, non-generalizable, and not intended to be able to be adapted to other purposes.” In other words, just make it up.
Do you suppose these other groups have an agenda?
John,
The official suggested WMO ‘climate normal’ period remains 1961-90, which will continue until 2021, when it will become 1991-2020: http://www.wmo.int/pages/themes/climate/climate_data_and_products.php
Worth noting that over the past 12 months UAH is in near exact agreement with the surface data sets when all are base-lined to the same anomaly period (bottom row of top table).
The obvious outlier is RSS, which is showing only about half the warming observed by all the other data sets.
In the USA the weather “normals” were updated and have been used for about 2 ½ years, I think. The WMO web page is either not updated or they don’t wish to follow their own rules. Because the 2001 thru 2010 averages are a bit higher, perhaps some folks hesitate to raise the baseline. Just a thought.
The Seattle KOMO TV weather blog has a long set of numbers from the National Weather Service that ends with [the all CAPS is the NWS stuff]:
NORMAL TEMPS AND PRECIPITATION ARE THE 1981 TO 2010 CLIMATE NORMALS.
http://www.komonews.com/weather/blogs/scott/Is-it-going-to-rain-on-Halloween-Just-flip-a-coin–229930451.html
This is dated Oct. 31, 2013 – So the 1981-2010 numbers were in use.
In a recent article on his website, Roy Spencer says:
“And, it is of continuing amusement to us that the global warming skeptic community now tracks the RSS satellite product rather than our UAH dataset. RSS was originally supposed to provide a quality check on our product (a worthy and necessary goal) and was heralded by the global warming alarmist community. But since RSS shows a slight cooling trend since the 1998 super El Nino, and the UAH dataset doesn’t, it is more referenced by the skeptic community now. Too funny.”
The difference between UAH and RSS seems to be mainly due to the manner in which they handle the polar regions.
http://www.drroyspencer.com/2014/10/why-2014-wont-be-the-warmest-year-on-record/
It is also interesting what else he has to say about surface dataset adjustments.
@QV
so which data set is the odd one out?
http://www.woodfortrees.org/plot/hadcrut4gl/from:1987/to:2015/plot/hadcrut4gl/from:2002/to:2015/trend/plot/hadcrut3gl/from:1987/to:2015/plot/hadcrut3gl/from:2002/to:2015/trend/plot/rss/from:1987/to:2015/plot/rss/from:2002/to:2015/trend/plot/hadsst2gl/from:1987/to:2015/plot/hadsst2gl/from:2002/to:2015/trend/plot/hadcrut4gl/from:1987/to:2002/trend/plot/hadcrut3gl/from:1987/to:2002/trend/plot/hadsst2gl/from:1987/to:2002/trend/plot/rss/from:1987/to:2002/trend/plot/uah/from:2002/to:2015/trend
HenryP
“so which data set is the odd one out?”
_____________________
That’s hard to answer because your WfTs chart: compares SST-only data (HadSST2) with land/sea data; contains the obsolete HadCRUT3; omits GISS; isn’t offset to a common base period; introduces a trend break at 2001/2.
This version uses only current land/sea sets from 1987 and is offset to UAH’s 1981-2010 base: http://www.woodfortrees.org/plot/hadcrut4gl/from:1987/offset:-0.29/plot/hadcrut4gl/from:1987/offset:-0.29/trend/plot/rss/from:1987/offset:-0.10/plot/rss/from:1987/offset:-0.10/trend/plot/gistemp/from:1987/offset:-0.39/plot/gistemp/from:1987/offset:-0.39/trend/plot/uah/from:1987/plot/uah/from:1987/trend
And from 2002: http://www.woodfortrees.org/plot/hadcrut4gl/from:2002/offset:-0.29/plot/hadcrut4gl/from:2002/offset:-0.29/trend/plot/rss/from:2002/offset:-0.10/plot/rss/from:2002/offset:-0.10/trend/plot/gistemp/from:2002/offset:-0.39/plot/gistemp/from:2002/offset:-0.39/trend/plot/uah/from:2002/plot/uah/from:2002/trend
RSS still the odd set out. RSS shows least warming since 1987 and is the only set that shows cooling since 2002. (HadCRUT4 only runs to July on WfTs. The latest version to Sep 2014 is flat since 2002).
RSS may be the “odd one out”, but that doesn’t make it wrong.
Roy Spencer pointed out the problems the surface based data sets have with data adjustments, UHI and incomplete locations. UAH and RSS both have issues with the way they handle the poles, in particular antarctica.
The fact is, none of the datasets is perfect, which can be seen from the error margins, which are often overlooked.
I agree with most of that QV. However, 4/5 producers of global temperature data, all using different methods, have reached more or less the same results to ‘best estimate’ accuracy. 1 disagrees with the rest.
The possibilities are: all are wrong; 1 is right and 4 are wrong; 4 are right and 1 is wrong. In almost any other specialised field we would say that it is ‘more likely’ that 4 are right and 1 is wrong.
But GISS and NCDC use exactly the same data, so you can hardly claim that they independently back each other. HADCRUT as well is heavily reliant on the same data.
Which leaves us with two satellite datasets coming up with two answers. As QV says, ina ny other specialised field we would not assume the “4” are probably right, we would instead accept that there is a wide margin of error.
(And of course this is precisely why few people would claim that, based on RSS, temperatures are on a cooling trend. As David Whitehouse correctly pointed out, there is no significan trend either way over the last decade or so)
As far as I know UAH and RSS share much of the same data too; or at least they have done previously. Most of it comes from MSUs on NASA satellites.
The producers all process the raw data they have differently, irrespective of whether it’s from surface stations or MSUs. Despite this, currently 4/5 producers are in agreement with one another re the central estimates in temperature trends for periods exceeding around 10 years. The exception is RSS. Why should we believe the exception to be right and the other 4 wrong?
Science does not work like that.
@QV
note my own 3 data sets
Click to access henryspooltableNEWc.pdf
(cooling trend, 3 x )