Here is another very useful review paper from arXiv by Indian scientists: Siingh, Gopalakrishnana, Singh, Kamraa, Singh, Panta, Singh, and Singh.
Research work in the area of the Global Electric Circuit (GEC) has rapidly expanded in recent years mainly through observations of lightning from satellites and ground-based networks and observations of optical emissions between cloud and ionosphere. After reviewing this progress, we critically examine the role of various generators of the currents flowing in the lower and upper atmosphere and supplying currents to the GEC. The role of aerosols and cosmic rays in controlling the GEC and linkage between climate, solar-terrestrial relationships and the GEC has been briefly discussed. Some unsolved problems in this area are reported for future investigations.
While it is often stated that cosmic rays may affect the climate / weather via cloud processes such as condensation of nuclei, the modification of the GEC through ionization effects on thunderstorm formation is also a possible factor.
They state that increased radiation enhanced the ionization in the atmosphere, which affected the charging mechanism of clouds leading to enhanced thunderstorm activity as was observed after Chernobyl accidents.
In particular, they claim latent heating/ rainfall and electrification/ lightning differ because the former is prevalent with shallow, gentle lifting of air, whereas the latter is caused by deeper and stronger lifting.