this is based on multiple lines of evidence including on observations already made in recent decades and on the projections of a range of different global climate models about future effects so even if global warming is contained within the range of c to c there will be very significant health and socioeconomic effects due to increasing average temperatures in addition and significantly for understanding and reducing risk humanity now faces the current reality and the future prospect of moreextreme and much higher frequency natural hazards extremes of cold to heatwaves longer and more sustained drought more intense and more frequent storm events heavier rainfall and more flooding