Would the occurrence of a Maunder-like solar minimum have reversed the observed climate change?

Abstract This study investigates a hypothetical scenario in which a prolonged solar minimum, such as the Maunder Minimum, is combined with the increase in CO2 emissions observed in the postindustrial period. For that, two fully-coupled state-of-the-art Earth system simulations were performed spanning the period 1850-2000. From the year 1950 onward, they differ on the radiative forcing. One accounts for the observed radiative forcing, including the increase in CO2 concentrations of the last decades, while the other adds the artifact of a decrease in the solar constant of similar magnitude as occurred during the Maunder Minimum four centuries ago, maintaining the increase in CO2. The model was evaluated by comparing the results of the simulations with the ERA5 data and the reanalysis of the 20th century, versions 2 and 3. In some evaluations in this study, meridional averages were made at 30-degree latitude cuts, in order to observe the differences between the effects of the Maunder Minimum in each region of the planet. It was possible to see a good consistency between the temperature differences in the second half of the 20th century simulated by CESM and the data from the reanalysis in all the regions analyzed, with the CESM variability remaining within what was observed between the reanalysis themselves. The results showed that comparing the period 1950-2000 with the period 1851-1949, it was found that the Maunder Minimum experiment managed to mitigate the warming of the planet in this period by around 50%, although it was unable to reverse it. In the periods where the greatest warming was observed, at the end of the 20th century, the Maunder Minimum had a most significant influence on reducing this warming in the Southern Hemisphere and in the section between 0-30°N, which could reduce this warming by almost 70%, and had a smaller or almost zero influence in the region between 30-90°N. However, even though the Maunder minimum mitigates warming, it has not systematically reversed this trend anywhere on the globe.