Extreme environments are shaped by a range of physical characteristics that make them challenging for human activity and fragile in ecological terms. This topic is central to IB Geography, particularly within Option C: Extreme Environments. Understanding these characteristics helps explain patterns of settlement, economic activity, and environmental vulnerability.
One of the most defining physical characteristics is climate. Extreme environments experience harsh climatic conditions that limit biological productivity. Hot deserts are characterised by very low rainfall, high temperatures, and intense evaporation. Cold environments such as polar regions and high mountain areas experience extremely low temperatures, ice cover, and short growing seasons. These climatic extremes restrict vegetation growth and water availability.
Precipitation patterns also play a key role. In many extreme environments, rainfall is either extremely low or highly seasonal. Deserts may receive less than 250 mm of rainfall per year, while polar regions receive little precipitation because cold air holds less moisture. In mountainous environments, precipitation may fall as snow, limiting immediate water availability and increasing avalanche risk.
Soil development is another important physical characteristic. Soils in extreme environments are often thin, nutrient-poor, and poorly developed. In cold environments, permafrost prevents deep soil formation and restricts drainage. In hot deserts, soils may be sandy or saline, with limited organic matter. Poor soils reduce vegetation cover and limit agricultural potential.
Water availability strongly shapes extreme environments. Many regions experience water scarcity, either because precipitation is low or because water is locked up as ice. Limited surface water reduces ecosystem productivity and increases vulnerability to drought. In cold environments, melting ice can create seasonal water flows, but these are unpredictable and sensitive to temperature change.
Extreme environments also tend to have low biodiversity. Harsh conditions limit the number of species that can survive. Plants and animals that do exist are highly specialised and adapted to extreme temperatures, limited water, or poor soils. Because ecosystems are simple and slow to recover, they are particularly vulnerable to disturbance.
In IB Geography, physical processes such as weathering and erosion are also important. Freeze–thaw weathering is common in cold environments, breaking rock apart and increasing the risk of mass movement. In deserts, wind erosion and occasional flash floods shape landscapes rapidly despite low rainfall.
Finally, extreme environments are often physically isolated. Rugged terrain, ice cover, or vast distances limit accessibility. This isolation reduces human impact in some areas but also makes rescue, management, and infrastructure development more difficult.
Overall, extreme environments are shaped by harsh climates, limited water, poor soils, low biodiversity, and active physical processes. These characteristics explain both their fragility and the challenges of human use.
RevisionDojo helps IB Geography students understand the physical characteristics of extreme environments clearly, linking climate, processes, and ecosystems into confident, exam-ready explanations.
