Structural
bias uncertainty estimate comes from three independent proxy types, each with a 2 - sigma of 3C, so the 2 - sigma on the mean is about + -1.7 C.
Not exact matches
First, the quality of the data is important: whether it is the LGM temperature
estimates, recent aerosol forcing trends, or mid-tropospheric humidity — underestimates in the
uncertainty of these data will definitely
bias the CS
estimate.
This is not simply the
uncertainty in
estimating the linear trend, but the more systematic
uncertainty due to processing problems, drifts and other
biases.
First, the quality of the data is important: whether it is the LGM temperature
estimates, recent aerosol forcing trends, or mid-tropospheric humidity — underestimates in the
uncertainty of these data will definitely
bias the CS
estimate.
The IPCC range, on the other hand, encompasses the overall
uncertainty across a very large number of studies, using different methods all with their own potential
biases and problems (e.g., resulting from
biases in proxy data used as constraints on past temperature changes, etc.) There is a number of single studies on climate sensitivity that have statistical
uncertainties as small as Cox et al., yet different best
estimates — some higher than the classic 3 °C, some lower.
A better approach would be to use a window of months about the current month to obtain a time - dependent
estimate of both the
bias and the
uncertainty due lack of coverage.
We can apply my simpler
bias analysis (which we can now see is limited in that it does not provide an
uncertainty estimate for the
estimated bias) to HadCRUT3 / 4.
Using the whole period of data leads to an
uncertainty estimate which is a compound of the desired
uncertainty, and a
bias estimate based on an average over the total span of the reanalysis dataset.
Lyman and colleagues combined different ocean monitoring groups» data sets, taking into account different sources of
bias and
uncertainty — due to researchers using different instruments, the lack of instrument coverage in the ocean, and different ways of analyzing data used among research groups — and put forth a warming rate
estimate for the upper ocean that it is more useful in climate models.
A time series of global - average,
bias - adjusted SSTs with all
uncertainty estimates combined is shown in Figure 11.
They are simply a first estimate.Where multiple analyses of the
biases in other climatological variables have been produced, for example tropospheric temperatures and ocean heat content, the resulting spread in the
estimates of key parameters such as the long - term trend has typically been signicantly larger than initial
estimates of the
uncertainty suggested.
At that point, we were linearly incorporating the
estimated biases rather than their
uncertainties.
Finally, the
estimates of
biases and other
uncertainties presented here should not be interpreted as providing a comprehensive
estimate of
uncertainty in historical sea - surface temperature measurements.
«Introduce» suggests that previous
estimates of the «
uncertainties» have strongly under
estimated the «Type B» or
bias uncertainties.
Uncertainties of estimated trends in global - and regional - average sea - surface temperature due to bias adjustments since the Second World War are found to be larger than uncertainties arising from the choice of analysis technique, indicating that this is an important source of uncertainty in analyses of historical sea - surface
Uncertainties of
estimated trends in global - and regional - average sea - surface temperature due to
bias adjustments since the Second World War are found to be larger than
uncertainties arising from the choice of analysis technique, indicating that this is an important source of uncertainty in analyses of historical sea - surface
uncertainties arising from the choice of analysis technique, indicating that this is an important source of
uncertainty in analyses of historical sea - surface temperatures.
Until multiple, independent
estimates of SST
biases exist, a signicant contribution to the total
uncertainty will remain unexplored.
The major
uncertainties in satellite measurements of upper air temperature are due to sensor and spacecraft
biases and instabilities, the characteristics of which need to be
estimated by performing satellite intercalibrations during overlapping intervals.
To suggest that this may be a taken as a validation of F&P requires rigorous validation of these two assumptions and a formal error
estimate for the
uncertainty of the hindcast to 1850 showing it to be substantially smaller than F&P
bias that is being evaluated.
The background to the hypotheses and the initial checks of the HadSST3 data set are given in the HadSST3 paper as is the
uncertainty analysis associated with difficulties in
estimating the
biases.
This
bias may be explained by a misrepresentation of mixed - phase extratropical clouds, often pinpointed as playing a key role in driving global - cloud feedback and
uncertainties in climate sensitivity
estimates (e.g., Tan et.
and «no data or computer code appears to be archived in relation to the paper» and «the sensitivity of Shindell's TCR
estimate to the aerosol forcing
bias adjustment is such that the true
uncertainty of Shindell's TCR range must be huge — so large as to make his
estimate worthless» and the seemingly arbitrary to cherry picked climate models used in Shindell's analysis.
In terms of remediation of the friction of scepticism in science, in recent years I have been stressing the proper, classic use of
estimates of
uncertainty in data, particularly one - sided
bias mechanisms.
Sure, the case can be made that documented TOB changes implies an adjustment to records to remove a
bias, plus added
uncertainty because the adjustment is an
estimate.
The
uncertainty in method
bias for any of these adjustment algorithms has to be
estimated differently and is possible, I think, with proper benchmark testing, as I noted previously, where at least we can determine the limitations of these approaches..
The wedge labelled «
Estimated ARC trend
uncertainty» represents the spread of potential
bias in the satellite data relative to the end of the time series.
The
uncertainty, and potential for politically motivated
bias, in all such SCC
estimates is astronomical, no matter who does them.
«Despite the wealth of metadata that is now available, it is not possible to
estimate the
biases in an exact manner so an attempt has been made to assess the potential
uncertainties in the
biases that arise from assumptions made in the process of aggregating the information.
a
Uncertainties (2 sigma) du to: data gaps and random errors
estimated by RSOA (heavy solid); SST
bias - corrections (heavy dashes); urbanisation (light dashes); changes in thermometer exposures on LAT (light solid).
The two obvious contributors to the
uncertainty are the structural
biases in the proxies and the sampling error from
estimating GAST from 5 - 61 SST observations.
FWIW: Your handwaving argument
estimating what the
bias in instrumental measurements based on
uncertainty in IPCC projections of warming is fundamentally unsound.
However unlike the Jones et al.
estimates of
uncertainty, the optimum average also includes
uncertainties in
bias corrections to SST up to 1941 (Folland and Parker, 1995) and the
uncertainties (as included in Figure 2.1) in the land data component that are due to urbanisation.
We are most confident in the methodological strengths of the longitudinal design and future longitudinal analyses.7 More caution is needed in interpreting our prevalence
estimates, but in spite of the methodological
uncertainties of using a non-probabilistic sample, we believe this, like many other quota samples, is likely to give
estimates similar to a probabilistic sample (which may be subject to different
biases, as we have shown with the NATSISS).23