Recently, Kalnay and Cai (2003) found a substantial land-use bias in U.S. temperatures by adjusting radiosonde records to surface altitude. We find that when this adjustment is applied evenly through time to the Historical Climate Network United States average temperature time series, the long-term significant warming trend in the USHCN record is reduced to a value becomes statistically insignificant. If such non-greenhouse related influences were operating globally, the impact on the globally-averaged surface temperature record may be large. Such a finding would be quite disturbing to the long-standing notions as to the impacts of increased atmospheric concentrations of greenhouse gases.

In order to examine the possibility that economic influences are significantly modifying the observed temperature history from locations around the world, we compared observed rates of warming for 218 stations from 93 countries. We simultaneously examined greenhouse and economic effects on those warming rates beginning in 1979, in order to be concurrent with the MSU-satellite record. Non-greenhouse factors we use included economic growth and proxies for the quality of record. In general, we found that in the winter half-year, greenhouse warming was the dominant signal, resulting mainly from the warming of cold anticyclones. However, in the summer half-year the economic influences were dominant and the greenhouse index was insignificant.

The implication is that problems in temperatures histories such as those uncovered by Kalnay and Cai (2003) may be global, although the strong warming of the winter anticyclones may still leave a detectable non-economic, non-land-use-change warming in overall annual records.