TITLE:
Difficulties in Reducing Atmospheric CO2 Concentrations during the Modern Warm Period
AUTHORS:
Masaharu Nishioka
KEYWORDS:
Global Warming, Global CO2, Anthropogenic CO2, Thermally Induced CO2, Soil Respiration, Cross-Correlation, Time Lag, El Niño
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.15 No.2,
April
22,
2025
ABSTRACT: According to the IPCC, when anthropogenic CO2 emissions increase, the atmospheric CO2 concentration increases, and the temperature increases due to the greenhouse effect of CO2. In the mechanism derived in our recent papers, the rise in temperature during the modern warm period increases CO2 emissions due to an increase in soil respiration (Rs control process). The CO2 emitted due to an increase in temperature can be considered thermally induced CO2. Therefore, although there is a correlation between temperature and CO2 concentration, there is a temperature-leading time lag due to the Rs control process. In this work, we analyzed the relationships between temperature changes and CO2 concentration changes in detail. As a result, we found that even if anthropogenic CO2 decreases, it is difficult to reduce the atmospheric CO2 concentration because of the large Rs control process during the modern warm period. One of the main reasons is that the Rs control process in midlatitude forests is significantly affected by temperature changes, which also means that the increase in anthropogenic CO2 since the Industrial Revolution has had only a small effect on the change in global CO2 concentrations.