Climate Science has emphasized the importance of monitoring the variability and trends of ocean heat content as the most appropriate and accurate way to assess global warming and cooling (i.e., the radiative imbalance of the global climate system); e.g., see
Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335.
This perspective has also been provided in the other papers also; e.g.,:
Levitus, S., J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon, and A.J. Broccoli, 2001: Anthropogenic warming of Earth’s climate system. Science, 292, 267-269.
Barnett, T.P., D.W. Pierce, and R. Schnur, 2001: Detection of anthropogenic climate change in the world’s oceans. Science, 292, 270-274.
Recently, Climate Science proposed a challenge to the models in their ability to predict ocean heat content changes; see
There is a critically important new paper on the reasons for sea level rise, that has been accepted in the Journal of Geophysical Research, which adds important new insight into this subject, as well as updates our knowledge of the recent trends in the global ocean heat content (and thus the global radiative imbalance). This paper is
Willis, J. K., D. P. Chambers and R. Steven Nerem, 2008: Assessing the Globally Averaged Sea Level Budget on Seasonal and Interannual Time Scales. Journal of Geophysical Research-Oceans (in press).
The abstract reads
“Analysis of ocean temperature and salinity data from profiling floats along with satellite measurements of sea surface height and the time variable gravity field are used to investigate the causes of global mean sea level rise between mid-2003 and mid-2007. The observed interannual and seasonal fluctuations in sea level can be explained as the sum of a mass component and a steric (or density related) component to within the error bounds of each observing system. During most of 2005, seasonally adjusted sea level was approximately 5 mm higher than in 2004 due primarily to a sudden increase in ocean mass in late 2004 and early 2005, with a negligible contribution from steric variability. Despite excellent agreement of seasonal and interannual sea level variability, the 4-year trends do not agree suggesting that systematic long-period errors remain in one or more of these observing systems.”
An important conclusion from the paper is that
“Despite the short period of the present analysis, these results have important implications for climate. First, from 2004 to the present, steric contributions to sea level rise appear to have been negligible. This is consistent with observations of ocean surface temperature, which show relatively little change in the global average between 2003 and 2006 [Smith and Reynolds, 2005, see NCDC global surface temperature anomalies]. It is in sharp contrast, however, to historical analyses of thermal expansion over the past decade [Willis et al., 2004] and the past half-century [Antonov et al., 2005; Lombard et al., 2005; Ishii et al., 2006]. Although the historical record suggests that multiyear periods of little warming (or even cooling) are not unusual, the present analysis confirms this result with unprecedented accuracy.”
The above paragraph reinforces a conclusion reached on Climate Science that global warming, at least as diagnosed by tropospheric and upper ocean heat content (see), has not been occurring since 2004. It is impossible to know if this lack of warming will continue, but these observations are inconsistent with the predictions of the long-term global climate predictions, such as reported in the 2007 IPCC report.