See
Act on Copenhagen: The impact of a global temperature rise of 4ºC (7 ºF)
It was developed using the latest peer-reviewed science from the Met Office Hadley Centre and other leading impact scientists.
The average land temperature will be 5.5 degrees above pre-industrial levels.
The impacts on human activity shown on the map are only a selection of those that may occur, and highlight the severe effects on water availability, agricultural productivity, extreme temperatures and drought, the risk of forest fire and sea level rise.
Agricultural yields are expected to decrease for all major cereal crops in all major regions of production. Half of all Himalayan glaciers will be significantly reduced by 2050, leading to 23% of the population of China being deprived of the vital dry season glacial melt water source.