Linking Hemispheric Warming Asymmetry to Anthropogenic Waste Heat

Nabil H Swedan

This paper proposes a potential link between the observed hemispheric warming asymmetry and the distribution of population and per capita energy consumption. Nearly 87% of the world’s population resides in the northern hemisphere, where per capita energy consumption has also been substantially higher than in the southern hemisphere. Consequently, anthropogenic waste heat discharged into the northern hemisphere has exceeded that discharged into the southern hemisphere, thereby contributing to the observed thermal asymmetry. Anthropogenic waste heat production in the hemispheres is primarily associated with global industrial activity and power generation, which have a thermodynamic efficiency of 43–48% ± 22%. Thermodynamic analysis of these processes over the period 2000–2025 yielded sea temperature increases of 0.53 ± 0.04 °C in the northern hemisphere and 0.21 ± 0.02 °C in the southern hemisphere. The corresponding observed increases are 0.63 °C and 0.38 °C, respectively. The differences between the calculated and observed hemispheric temperature increases are 21.9% or less. However, the calculated average sea-surface temperature trend agrees closely with the observed trend reported by the Intergovernmental Panel on Climate Change. Accordingly, the calculated hemispheric temperature increases are considered representative, suggesting that hemispheric warming asymmetry may be attributed to anthropogenic waste heat. Recent studies reveal that the intensification of the El Niño–Southern Oscillation may be attributed to hemispheric warming asymmetry. Therefore, this study may contribute to a better understanding of the causes of climatic extremes and their mitigation.