Severe storms and their related phenomena (tornadoes, hail, lightning, downdrafts, ...) are part of climate, so their frequency and intensity distributions should change according to global and regional climate changes. Moreover information concerning the possible effects of climatic forcing on severe storms' frequency and intensity are pivotal for decision makers, stakeholders and common people as well. Nowadays several well tested numerical climatic models are available and they can give useful information on global future scenarios according to the assumed forcing (doubling of CO2, etc). Unfortunately, severe storms live and evolve too deep inside the computational grids of numerical models; for this reason poor information is expected to spring from the currently available numerical tools.
One of the possibilities for obtaining information concerning the effects of climate change on severe storms and related phenomena passes through the development of newly conceived numerical models nested within the well known and tested classical ones. The principal objection to this strategy refers to the current lack of information at meso-scale and storm-scale for a correct initialization of the numerical models. However in situations where the main cause of deep moist convection onset is related to synoptic or slightly sub-synoptic flows, specially for areas characterized by complex orography, non hydrostatic numerical climatic models, nested within global or regional climatic models might give useful hints concerning the change in the severe storms' frequency and intensity.
Another possibility for facing the question of the change in severe storm climate passes through a deep understanding of severe storms physical climatology. Knowing the dynamical and thermodynamical causes for the onset and development of deep moist convection in a specific region, i.e., the so called ingredients we might guess how severe storms frequency and intensity distributions should change according to the changes in the ingredients due to the global and regional climate changes.
A third way to study the effects of climate changes on severe storms can be represented by a purely statistical approach based on tele-connections. In some regions of the World, severe storms seem to be related to the flow dynamic modes such as the North Atlantic Oscillation, the Eastern Oscillation etc., by the large scale weather types or by atmosphere-sea interaction modes, such as el Niņo/la Niņa. Provided that these relationships are statistically sufficiently robust, they might be used to create a bridge between the effects of climate change on dynamic modes, then on severe storms frequency and intensity.
Because of their economical and social relevance, contributions on the effects of global and/or regional climate change on severe storms according to the above and/or alternative approaches are expected and welcome.