The transition from high to very high risk-that is severe and widespread impacts with limited ability to adapt-begins either at or just below 2ºC for all three risks . The assessed temperature range for the transition to very high risk is wider for food production than for biodiversity and health. Projected impacts for food include: 10-30% decline in marine fisheries catch potential for the Horn of Africa region and southern Africa and more than 30% decline for west Africa at 2°C global warming, with greater declines at higher levels of warming . Beyond 2°C global warming, over 50% of commercially important freshwater fish species across Africa are projected to be vulnerable to extinction . Between 2°℃ and 4ºC, wheat, maize and rice yields are projected, on average, to be lower than 2005 yields across all regions of Africa. From 2℃ global warming, over 40% losses in rangeland productivity are projected for western Africa. By 3.75ºC, severe heat stress may be near year-round for cattle across tropical Africa . Multiple countries in west, central and east Africa are projected to be at risk from simultaneous negative impacts on crops, fisheries and livestock .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report