A warmer globe means more energy in the climate system, fuelling phenomena such as hurricanes, and the cyclical event known as El Ni o which affects the climate all around the globe. The frequency of El Ni o events appears to be increasing from every 6 years, to 3.5 years and leading to ever more extreme weather events. Up to 300m more people worldwide could be at risk of the dangerous falciparum malaria, particularly in China and Central Asia. Some diseases could become more prevalent as a consequence of extreme weather events and the resulting destruction of infrastructure, such as cholera, typhoid, malaria and dengue fever. Effects on society Human society will face new risks and pressures.
Some regions are likely to experience food shortages.
Water resources will be affected as precipitation and evaporation patterns change around the world, and this may lead to conflict as nations compete for limited water supplies. Physical infrastructure will be damaged, particularly by sea-level rise and by extreme weather events. Economic activities, human settlements, and human health will experience many direct and indirect effects. The poor and disadvantaged are the most vulnerable to the negative consequences of climate change.