Glaciers are not entirely absent from South America and Africa, but their presence is highly constrained by geography and climate. Glaciation on these continents is restricted compared to the massive ice sheets of North America or Eurasia. Glacier formation requires a specific combination of high altitude, consistent precipitation, and persistent cold temperatures to accumulate ice year after year.
The Climatic Requirements for Glacier Formation
Glaciers form only where the annual accumulation of snow exceeds the total loss from melting, sublimation, and calving. This requires two conditions: sufficiently cold temperatures and ample solid precipitation. Temperatures must remain low enough year-round to prevent the previous winter’s snow from melting during the summer. Surviving snow transforms into firn, which eventually compresses into glacial ice under its own weight.
The elevation above which snow survives the summer is called the snow line, which relates to the equilibrium line altitude (ELA) for a glacier. The ELA is the boundary between the accumulation zone (mass gained) and the ablation zone (mass lost). While the ELA can be near sea level in polar regions, the required altitude increases dramatically closer to the equator. For a mountain to support a glacier in the tropics, its peak must rise well above this high ELA to ensure sufficient snow accumulation.
South America: Glaciation Along the Andes
South America hosts one of the world’s most extensive glacial systems outside of the polar regions, stretching along the 8,900-kilometer spine of the Andes Mountains. The Andes provide the necessary high-altitude terrain, but ice distribution is highly uneven, dictated by latitude and moisture delivery. The largest ice masses are supported by the Patagonian Andes in the far south.
The immense Southern Patagonian Ice Field is sustained by its high latitude and intense moisture. This region receives abundant precipitation from Pacific storm systems, allowing glaciers to descend to very low elevations, sometimes reaching sea level. In contrast, the tropical Andes (Peru, Ecuador, and Colombia) host glaciers only at extremely high altitudes, typically above 4,800 meters.
These tropical glaciers are highly sensitive, existing in a climate where air temperature hovers near freezing year-round, causing a unique daily freeze-thaw cycle. In the drier central Andes, the snow line rises to between 4,500 and 5,200 meters. This requires only the highest peaks to be capped with ice, confining South America’s extensive glaciers almost entirely to the Andean chain.
Africa: Equatorial Constraints and Extreme Rarity
Africa’s glaciated area is minuscule, concentrated on only a few isolated, exceptionally high peaks near the equator. Since the continent is predominantly tropical, the required altitude for the ELA is extremely high, making glacier formation nearly impossible. The few remaining glaciers are found on Mount Kilimanjaro (Tanzania), Mount Kenya (Kenya), and the Rwenzori Mountains (Uganda/DRC).
These mountains barely reach the necessary height to sustain ice, and their glaciers are small, fragmented remnants of a colder past. For example, Mount Kilimanjaro has lost over 90 percent of its ice area since the early 1900s. Although equatorial air temperature at these altitudes is near freezing, the overall lack of adequate snowfall is a major limiting factor.
The tropical location also subjects the ice to high solar radiation, which drives sublimation. Furthermore, these mountains lack the continuous, vast mass of the Andes, offering only isolated, marginally cold environments on their summits. This combination of high ELA, low precipitation, and intense solar radiation explains the extreme rarity and rapid disappearance of Africa’s few remaining glaciers.