Global Warming “has not occurred in the last 4 years”
From Roger Pielke, Sr. “Climate Science” “Reality Check On This Year’s Cold and Snowy Weather – Implications For Global Warming“: we can state that global warming has not occurred in the last 4 years
With respect to the change in upper ocean heat content, as reported on a Climate Science weblog on February 15 2008, the paper
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),
reports on no upper (700m) ocean warming since 2004.
Thus while we cannot state that the recent widely distributed cold waves or overall cooling of the troposphere are evidence of the end of global warming over decadal and longer time scales, we can state that global warming has not occurred in the last 4 years. This is a major issue for both climate science and for policymakers, as only those who blindly (or deliberately) ignore the scientific evidence can still accept the 2007 IPCC conclusions as settled science.
This is part of the original quote from Chambers and Nerem:
“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.”