18 November 2012: The World Bank has released a scientific report titled, “Turn Down the Heat: Why a 4°C Warmer World Must be Avoided.” The report, prepared by the Potsdam Institute for Climate Impact Research (PIK) and Climate Analytics, examines the implications of a four degree Celsius increase in global mean temperatures by the end of the century.

The report highlights projected impacts, including annual heatwaves of between four and ten degrees Celsius above summer averages, a 150% increase in ocean acidity, one meter increases in sea level rise, severe changes to rainfall patterns and increases in extreme events. The report stresses that anticipated temperature increases are expected to significantly impact human and biological systems. In particular, the report notes that anticipated changes in water availability, ecosystems, agriculture and human health may lead to reduced food and water security, increased infrastructure damage and disruptions to livelihoods and economies. The report further states that impacts are projected to be uneven, with more severe impacts in the tropics and sub-tropics. Still, the report emphasizes that all regions will be impacted to some extent, either directly and indirectly, due to global economic impacts and risks of displacement.

The report includes sections on: observed climate changes and impacts; 21st century projections; sea-level rise projections; changes in extreme temperatures; sectoral impacts on agriculture, water, biodiversity and health; and cross-sector risk assessments. It includes projections based on models as well as scenarios depending on response activities, management practices and adaptation measures. [Publication: Turn Down the Heat]