evidence: Jones et al. (1990) determined that the impact of urbanization on hemispheric temperature time series was, at most, 0.05°C century−1. This result was based on the work of Karl et al. (1988) for the United States and further analysis of three other regions: European parts of the Soviet Union, eastern Australia, and eastern China. "In none of these three regions was there any indication of significant urban influence in either of the two gridded time series relative to the rural series" (Jones et al. 1990). The homogeneity assessments varied with regions. The data for one region "were assessed for artifacts due to factors such as site moves or changing methods used to calculate monthly mean temperatures." Another region used data from stations "with few, if any, changes in instrumentation, location or observation times." The homogeneity of data used in the third region was not discussed. Their results showed that the urbanization influence "is, at most, an order of magnitude less than the warming seen on a century scale."