We aimed at addressing how the weakening of the geomagnetic field affects cloud properties and climate, and whether this weakening could lead to an environmental crisis, as suggested by paleoclimatic data. To investigate this, we performed climate simulations driven by the relationship between geomagnetic field strength, atmospheric ionization rates, global electric circuit, and the cloud life cycle. The ionization rates were calculated using a model applicable to both regular and geomagnetic excursion periods. Our model modifications focused specifically on the cloud parameterization scheme, introducing a dependency of the cloud droplet coagulation on the global electric field strength. This dependency was determined as a function of fair weather vertical electric currents (J_z), which were interactively calculated from the simulated atmospheric ion concentrations and conductivity. The model results indicate that the impact of the geomagnetic field weakening on the atmospheric electrical currents is the most pronounced in the middle and low latitudes, leading to an increase in J_z of up to 20%. We also observed statistically significant changes in cloud cover and surface cooling of about 0.4K in global and annual mean surface temperatures. Local and seasonal effects are even more pronounced; for instance, substantial temperature drops of up to 2 K are observed in the Northern Hemisphere. These findings will be described in further detail during the talk. However, based on our results, we cannot conclude that the introduced mechanism would lead to a large-scale environmental crisis. This work is supported by the Swiss National Science Foundation (project Spark GECO; CRSK-2_221368).