Contributions of Sunshine Duration and Atmospheric CO2 to Surface Air Warming in Central Europe from 1915 to 2024 and Empirical Relationship Between Atmospheric CO2 and Global Emissions

The aim of this study is to quantify the impact of increased surface solar radiation on climate warming in Central Europe from 1915 to 2024 and to examine the relationship between CO2 air concentrations and emissions on a global scale with an empirical approach. A statistical model with proxies for short-wave and long-wave radiation (sunshine duration SSD and CO2 concentration) as independent variables and surface air temperature as the dependent variable was tested for validity and significance, and the results were presented for six long-term measuring stations in Central Europe. The statistical model fulfilled all tests (error probability, normal distribution of the residuals, autocorrelation, statistical power, multicollinearity) and showed that the increase in SSD in the entire year accounts for around 20% of the warming over the last 100 years; in the summer half-year (April–September) and summer (June–August) it is around 30%. The increase in CO2 concentration accounts for the remainder portion of warming of 70–80%. Studies and models neglecting the influence of the increase in surface solar radiation are overestimating the influence of GHG on warming. A lifetime concept for CO2 was evaluated empirically for the last 130 years: the development of CO2 air concentration from industrialization until today can be mapped very well with a lifetime of 58 years. With this lifetime, reducing annual CO2 emissions by around half would stabilize CO2 concentrations. The contrasting concept of cumulative CO2 emissions, according to which stabilization can only be achieved with ‘zero emissions’, is discussed in this context.