The Influence of Economic Activity on the Measurement of Global Warming
Guelph Dept. of Economics Working Paper No. 2001-2
36 Pages Posted: 26 Sep 2001
Date Written: September 2001
Upward-trending graphs of global surface temperatures are presented as evidence of global warming on the assumption that weather stations only register climatic changes, as opposed to, say, growth in economic activity in the vicinity of the thermometers, or the deterioration of the measurement infrastructure. In order to test this assumption an empirical model is developed that separately identifies climatic, economic and measurement effects on surface temperature records.
Monthly surface temperature records from 1979 to 2000 were obtained from 218 individual sites in 93 countries. A linear trend coefficient was computed at each site. Then lower tropospheric air temperature data from US weather satellites for each of the same locations over the same interval were retrieved, and the location-specific trend was computed. The vector of trends measured at the surface was regressed on the vector of satellite-measured trends, as well as indicators of local economic activity (income, GDP growth rates, coal and oil use) and local measurement skill (the number of missing observations, local literacy and a dummy for Soviet Bloc membership).
After controlling for air temperature changes, the spatial pattern of measured trends is shown to be affected by local income levels, literacy and whether the data come from the former Soviet Union. Using the regression model to remove these effects leaves an average global warming trend of about one-fifth the conventionally-reported magnitude.
Keywords: Climate change, economic growth, measurement quality
JEL Classification: Q01, Q2
Suggested Citation: Suggested Citation