This article in the January/February edition of WIRES Climate Change doesn’t surprise me at all. With the uncertainty of the surface temperature record in question, the Met Office’s Peter Thorne and NCDC’s Tom Peterson, who once wrote a ghost authored attack against the surfacestations project, take aim to elicit controversy (their word) over Christy and Spencer’s satellite derived temperature record.
Personally, I have little trust of NCDC’s motives, and especially Peterson, after his ghost authored attack on me and the surfacestations project. A true scientist doesn’t need to write ghost articles to discredit the work of others. I’ve put my name on every criticism I ever made of the surface temperature record and NCDC. I thought it was the ultimate cheap shot that Peterson and NCDC didn’t, and then posted it to the NCDC main web page. Remember, this is the same NCDC that used photoshopped flooded houses in government reports. But I digress.
I’ve posted a figure below, along with the abstract and concluding remarks from the article, it is well worth a read.
Tropospheric temperature trends: history of an ongoing controversy
Peter W. Thorne, John R. Lanzante, Thomas C. Peterson, Dian J. Seidel and Keith P. Shine
Changes in atmospheric temperature have a particular importance in climate
research because climate models consistently predict a distinctive vertical profile
of trends. With increasing greenhouse gas concentrations, the surface and
troposphere are consistently projected to warm, with an enhancement of that
warming in the tropical upper troposphere. Hence, attempts to detect this distinct
‘fingerprint’ have been a focus for observational studies. The topic acquired
heightened importance following the 1990 publication of an analysis of satellite
data which challenged the reality of the projected tropospheric warming. This
review documents the evolution over the last four decades of understanding
of tropospheric temperature trends and their likely causes. Particular focus
is given to the difficulty of producing homogenized datasets, with which to
derive trends, from both radiosonde and satellite observing systems, because of
the many systematic changes over time. The value of multiple independent
analyses is demonstrated. Paralleling developments in observational datasets,
increased computer power and improved understanding of climate forcing
mechanisms have led to refined estimates of temperature trends from a wide
range of climate models and a better understanding of internal variability. It is
concluded that there is no reasonable evidence of a fundamental disagreement
between tropospheric temperature trends from models and observations when
uncertainties in both are treated comprehensively.
There is an old saying that a person with one watch always knows what time it is, but with two watches one is never sure. The controversy over surface and tropospheric temperature trends started in 1990 when the first satellite upper air ‘watch’ was produced
and it was na¨ıvely assumed that it told the correct time. Over the subsequent years, with the advent of not just two but multiple watches from different ‘manufacturers’ and using two distinct ‘technologies’, a more accurate measure of the structural uncertainty
inherent in estimating what the ‘time’ truly is has emerged.
The state of the observational and model science has progressed considerably since 1990. The uncertainty of both models and observations is currently wide enough, and the agreement in trends close enough, to support a finding of no fundamental discrepancy between the observations and model estimates throughout the tropospheric column. However, the controversy will undoubtedly continue because some estimates of tropospheric warming since 1979 are less than estimates of surface warming, or fall outside of the range of analogous model estimates (e.g., Figure 8).
There are several key lessons for the future:
1. No matter how august the responsible research group, one version of a dataset cannot give a measure of the structural uncertainty inherent in the information.
2. A full measure of both observational uncertainty and model uncertainty must be taken into consideration when assessing whether there is agreement or disagreement between theory (as represented by models) and reality (as represented by observations).
3. In addition to better routine observations, underpinning reference observations are
required to allow analysts to calibrate the data and unambiguously extract the true climate signal from the inevitable nonclimatic influences inherent in the routine observations.
#3 What? The “true climate signal” hasn’t been extracted? And, “inevitable nonclimatic influences”? What, noise and uncertainty? What a concept! I agree though, that better routine and reference observations are needed. Problem is, we don’t have much of that that extends back 100+ years. The Climate Reference Network in the USA was only recently completed, and many countries have no equivalent. We really have very little surface data that is free of “inevitable nonclimatic influences inherent in the routine observation”. Are we getting better at pulling the signal from the noise? Yes. Have we got it right yet? I’m doubtful.
I also find lesson #2, “observational uncertainty” quite interesting, given that we’ve just shown the high level of “observational uncertainty” in the US Historical Climate Network with Fall et al 2011. We all need to get a better handle on this, as well as the “observational uncertainty” of the Global HCN, which NCDC’s Tom Peterson just happens to manage.
The full article is here Thorne_etal_2011 h/t to Dallas Staley