பூமி அறிவியல் & காலநிலை மாற்றம் இதழ்

சுருக்கம்

The Correlation of Seismic Activity and Recent Global Warming

Arthur Viterito

The latest report from the Intergovernmental Panel on Climate Change states with high confidence that the warming of global temperatures since 1901 has been driven by increased radiative forcing. The gases responsible for this enhanced forcing are greenhouse gases of anthropogenic origin, and include carbon dioxide, methane, and halocarbons. The Nongovernmental International Panel on Climate Change has challenged these findings and concludes that the forcing from greenhouse gases is minimal and diminishing. They add that modelling attempts of past and future climate states are inaccurate and do not incorporate important solar inputs, such as magnetic strength and total irradiance. One geophysical variable that has been overlooked by both groups is geothermal flux. This study will show that increasing seismic activity for the globe’s high geothermal flux areas (HGFA), an indicator of increasing geothermal forcing, is highly correlated with average global temperatures from 1979 to 2015 (r = 0.785). By comparison, the correlation between carbon dioxide loading and global temperatures for the same period is lower (r = 0.739). Multiple regression indicates that HGFA seismicity is a significant predictor of global temperatures (P < 0.05), but carbon dioxide concentrations do not significantly improve the explained variance (P > 0.1). A compelling case for geothermal forcing lies in the fact that 1) geothermal heat can trigger thermobaric convection and strengthen oceanic overturning, important mechanisms for transferring ocean heat to the overlying atmosphere, and 2) seismic activity is the leading indicator, while global temperature is the laggard.