Lightning hazards to human societies in a changing climate

Lightning is a natural hazard, lethal and destructive on short time scales and with important climatic effects on longer time-scales (through NOx production and forest fire ignition). It is accompanied by severe weather, hail and flash flooding that often entail significant economic losses. It also poses threats to aviation safety and to renewable energy production by wind-turbines, and is known to adversely affect electric power utilities and transmission lines. Present day global trends in urbanization, land-use and energy production are mapped to climate change through several scenarios, relating future concentrations of green-house gasses in the atmosphere ('Representative Concentration Pathways' or RCPs; IPCC et al 2013 Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge: Cambridge University Press) p 1535) to the adopted energy policies and international agreements. These scenarios predict a few degrees of atmospheric warming near Earth surface, which offer significantly different climatic regimes in many regions on Earth, and also affect the intensity and frequency of atmospheric natural disasters (e.g. tropical storms). Although it is hard to precisely predict what future lightning distributions will look like, the combination of large metropolitan areas, increased population and a warmer climate almost guarantee an intensification of the human exposure to lightning hazard. We review current trends in population, urbanization and technology usage and assess their vulnerability to future lightning activity in different scenarios.