Industrial CO2 emissions as a proxy for anthropogenic influence on lower tropospheric temperature trends

Abstract

Surface temperature trends during the last two decades show a significant increase which appears to be anthropogenic in origin. We investigate global temperature changes using surface as well as satellite measurements and show that lower tropospheric temperature trends for the period 1979–2001 are spatially correlated to anthropogenic surface CO2 emissions, which we use as a measure of industrialization. Furthermore, temperature trends for the regions not spatially correlated with these CO2 emissions are considerably smaller or even negligible for some of the satellite data. We also show, using the same measure, that two important climate models do not reproduce the geographical climate response to all known forcings as found in the observed temperature trends. We speculate that the observed surface temperature changes might be a result of local surface heating processes and not related to radiative greenhouse gas forcing.