The Santer Et Al (2000) View Of The Importance of Error In The Surface Temperature Record In Their Paper “Differential Temperature Trends At The Surface And In The Lower Troposphere”

In 2000 Ben Santer and colleagues published the paper [and thanks to Dick McNider for alerting us to it!]

B. D. Santer, T. M. L. Wigley, D. J. Gaffen, L. Bengtsson, C. Doutriaux, J. S. Boyle, M. Esch, J. J. Hnilo, P. D. Jones, G. A. Meehl, E. Roeckner, K. E. Taylor, and M. F. Wehner: Interpreting Differential Temperature Trends at the Surface and in the Lower Troposphere
 Science 18 February 2000 287: 1227-1232 [DOI: 10.1126/science.287.5456.1227] (in Research Articles).

The abstract reads

“Estimated global-scale temperature trends at Earth’s surface (as recorded by thermometers) and in the lower troposphere (as monitored by satellites) diverge by up to 0.14°C per decade over the period 1979 to 1998. Accounting for differences in the spatial coverage of satellite and surface measurements reduces this differential, but still leaves a statistically significant residual of roughly 0.1°C per decade. Natural internal climate variability alone, as simulated in three state-of-the-art coupled atmosphere-ocean models, cannot completely explain this residual trend difference. A model forced by a combination of anthropogenic factors and volcanic aerosols yields surface-troposphere temperature trend differences closest to those observed.”

In their paper, they briefly mention the effect of a possible error in the surface temperature data which could explain the discrepancy between the temperature trends in the troposphere and at the surface. They write

“A nonsignificant trend differential would also occur if the surface warming had been overestimated by 0.05°C per decade in the IPCC data … The relative likelihood of such errors in the MSU and IPCC data is difficult to assess…”

The IPCC (2007) Statement for Policymakers wrote

“New analyses of balloon-borne and satellite measurements of lower- and mid-tropospheric temperature show warming rates that are similar to those of the surface temperature record and are consistent within their respective uncertainties, largely reconciling a discrepancy noted in the TAR.”


“Eleven of the last twelve years (1995–2006) rank among the 12 warmest years in the instrumental record of global surface temperature9 (since 1850). The updated 100-year linear trend (1906 to 2005) of 0.74°C [0.56°C to 0.92°C] is therefore larger than the corresponding trend for 1901 to 2000 given in the TAR of 0.6°C [0.4°C to 0.8°C]. The linear warming trend over the last 50 years (0.13°C [0.10°C to 0.16°C] per decade) is nearly twice that for the last 100 years. The total temperature increase from 1850–1899 to 2001–2005 is 0.76°C [0.57°C to 0.95°C].”

Our paper

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., accepted

has clearly documented an estimated warm bias of about 30% in the IPCC reported  surface temperature trends.  This bias also brings into question the claim that 11 of the 12 years in the period 1995 to 2006 were the warmest on record.  Moreover, despite the claim in the IPCC (2007) report, the tropospheric and surface temperature trends have not NOT reconciled.

The lack of news coverage on this documented bias which has appeared in the peer reviewed literature on the Klotzbach et al (2009) paper is another clear example of the failure of most  of the journalism community to cover news that conflicts with the IPCC (2007) perspective.

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