Cross-Correlation between Global Temperature and Atmospheric CO 2 with a Temperature-Leading Time Lag

Abstract

The temperature change and rate of CO 2 change are correlated with a time lag, as reported in a previous paper. The correlation was investigated by calculating a correlation coefficient r of these changes for selected ENSO events in this study. Annual periodical increases and decreases in the CO 2 concentration were considered, with a regular pattern of minimum values in August and maximum values in May each year. An increased deviation in CO 2 and temperature was found in response to the occurrence of El Niño, but the increase in CO 2 lagged behind the change in temperature by 5 months. This pattern was not observed for La Niña events. An increase in global CO 2 emissions and a subsequent increase in global temperature proposed by IPCC were not observed, but an increase in global temperature, an increase in soil respiration, and a subsequent increase in global CO 2 emissions were noticed. This natural process can be clearly detected during periods of increasing temperature specifically during El Niño events. The results cast strong doubts that anthropogenic CO 2 is the cause of global warming.