The majority of African countries are stricken by food shortages and undernourishment, with much of the population lacking reliable access to food supplies and basic dietary requirements. In this paper, we analyze past trends of food production and consumption in Africa, both for the continent as a whole and for 52 individual countries within it. Fluctuations in the self-sufficiency ratio (SSR) are used to characterize the stability of a country’s capacity to sustain its own population, and GDP per capita is taken as representative of national purchasing power. Our study shows that Africa’s food self-sufficiency is lower today than it was throughout the entire study period. This is probably a result of demographic expansion, leading to a greater increase in food demand than in food production. At the national level, a decrease in SSR mainly occurred in Northern and Southern Africa, and high SSR fluctuations (i.e. low stability) always appeared in conjunction with low SSR levels. Although “low SSR-low GDP” countries face the most serious food insecurity conditions, both “low SSR-high GDP” and “high SSR-low GDP” countries also need attention.

We analyze simulated sea ice changes in eight different Earth System Models that have conducted experiment G1 of the Geoengineering Model Intercomparison Project (GeoMIP). The simulated response of balancing abrupt quadrupling of CO₂ (abrupt4xCO2) with reduced shortwave radiation successfully moderates annually averaged Arctic temperature rise to about 1°C, with modest changes in seasonal sea ice cycle compared with the preindustrial control simulations (piControl). Changes in summer and autumn sea ice extent are spatially correlated with temperature patterns but much less in winter and spring seasons. However, there are changes of ±20% in sea ice concentration in all seasons, and these will induce changes in atmospheric circulation patterns. In summer and autumn, the models consistently simulate less sea ice relative to preindustrial simulations in the Beaufort, Chukchi, East Siberian, and Laptev Seas, and some models show increased sea ice in the Barents/Kara Seas region. Sea ice extent increases in the Greenland Sea, particularly in winter and spring and is to some extent associated with changed sea ice drift. Decreased sea ice cover in winter and spring in the Barents Sea is associated with increased cyclonic activity entering this area under G1. In comparison, the abrupt4xCO2 experiment shows almost total sea ice loss in September and strong correlation with regional temperatures in all seasons consistent with open ocean conditions. The tropospheric circulation displays a Pacific North America pattern‐like anomaly with negative phase in G1‐piControl and positive phase under abrupt4xCO2‐piControl.