The method preferred by the GWPF report, and that which Lewis has used in his own papers, involves estimating climate sensitivity using a combination of recent instrumental temperature data (
including ocean heat content data), less complex climate models, and statistics.
That's just not true if
you include ocean heat content data to 2000 meters.
I prefer though my multi-cointegration papers that
include ocean heat content data.
Not exact matches
The increase in deep
ocean heat content is also a robust result in
data sets that do not
include reanalysis.
Several recent studies have also concluded that it is necessary to
include data from the deep
ocean in order to reconcile global
heat content and the TOA energy imbalance, which DK12 failed to do.
DK12 used
ocean heat content (OHC)
data for the upper 700 meters of
oceans to draw three main conclusions: 1) that the rate of OHC increase has slowed in recent years (the very short timeframe of 2002 to 2008), 2) that this is evidence for periods of «climate shifts», and 3) that the recent OHC
data indicate that the net climate feedback is negative, which would mean that climate sensitivity (the total amount of global warming in response to a doubling of atmospheric CO2 levels,
including feedbacks) is low.
The
data used in estimating the Levitus et al. (2005a)
ocean temperature fields (for the above
heat content estimates) do not
include sea surface temperature (SST) observations, which are discussed in Chapter 3.
The paper also
includes this useful table illustrating that according to observational
data,
ocean heat content has indeed accumulated rapidly in the deep
oceans in recent years.
However, as we recently discussed, the increase in deep
ocean heat content is a robust result in
data sets that do not
include reanalysis.
This
includes ocean heat content (it is more or less), GISS, Hadley etc global
data — and
includes raw
data and adjustment algorithms / codes.
We are still going to have to wait for the «definitive»
ocean heat content numbers, however, it is important to note that all analyses give long term increases in
ocean heat content — particularly in the 1990s — whether they
include the good ARGO
data or exclude the XBTs or not).
As for
ocean heat content, Argo hasn't been in the water long enough to show a clear signal, and there have been problems with the
data,
including a significant correction (you do recall the correction to the UAH satellite record after years of insistence that their
data showed the surface temp record trends were completely wrong?).
For more information,
including a discussion of the natural warming of
ocean heat content data, refer to my illustrated essay «The Manmade Global Warming Challenge» [42 MB].