Majority of the natural ice crystals are complex. This we have been able to show in field campaigns covering variety of geographical locations. The crystal complexity does to just affect the appearance of the ice crystals but also significantly alters their short wave angular light scattering properties. An enhanced backscattering is observed that, when incorporated to a global climate model, can increase the cooling effect of ice clouds. A recent article published in ACP links these field observations to climate modelling.