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 1,5°C to 2°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 more-extreme and much higher frequency "natural" hazards - extremes of cold to heat-waves, longer and more sustained drought, more intense and more frequent storm events, heavier rainfall and more flooding.