C Extreme environments

Extreme environments studies two kinds of place where climate and relief set severe limits on plants, people and economic activity: cold and high-altitude environments (polar regions, glacial and periglacial areas and high mountains) and hot arid environments (hot deserts and semi-arid areas). Drylands alone cover about 41% of the Earth’s land and are home to more than 2 billion people, while the Arctic is warming nearly four times as fast as the global average, so these places matter far beyond their small populations.

Questions that frame the option

The option follows four lines of geographical inquiry. The first asks why some places are considered extreme, and by whom. The second asks how physical processes create the distinctive landscapes of ice, frozen ground, sand and dry valleys. The third asks why states, companies, Indigenous peoples and tourists have such different power to extract economic value from these places. The fourth asks what futures are possible for extreme environments and their communities as land degrades, competition grows and the climate changes.

These inquiries lead to real questions that geographers try to answer with evidence:

• Why has Svalbard warmed by about 4 °C since 1971, about five times the global rate, and what does that mean for a town built on permafrost?

• Why does the Great Aletsch Glacier keep moving forward at about 180 m a year while its snout retreats up the valley?

• Who benefits from the lithium pumped from beneath the Salar de Atacama, and who bears the cost of the water it uses?

• Why did farmers in southern Niger restore trees on more than 5 million hectares while the Great Green Wall fell far behind its targets?

• Why did Norway’s Supreme Court rule in 2021 that two wind farms at Fosen violated Sámi herders’ rights, yet the turbines kept turning?

What the option covers

The option has four subtopics, and each one deals with both kinds of extreme environment, cold and arid. The first two explain the places and their landscapes; the last two deal with how they are used and what their future holds.

How the subtopics connect

The concept map shows the main links. Climate determines which processes dominate a place, so the characteristics of the first subtopic explain the glacial, periglacial and desert landscapes of the second. The same climate, with relief, remoteness and inaccessibility, raises the cost of farming, mining and tourism, which is why the challenges of the first subtopic run straight into the management questions of the third. The physical systems of the second subtopic change under warming, through permafrost thaw, glacier retreat and glacial lake outburst floods, and the way land and resources are used today shapes what is possible in the fourth.

At the centre of the map is power over land and resources. Who owns the subsoil, who holds land under custom rather than title, and whose consent a project needs determine whether a mine, a wind farm or a tourist route goes ahead. People and places in extreme environments are also tied to distant places: battery makers in Asia buy Chilean lithium, tourists fly to Antarctica from every continent, and the emissions that thaw Arctic permafrost come mostly from far away.

Key concepts in Extreme environments

The four key concepts run through the option, together with three concepts that belong to it in particular: glacial systems, risk and adaptation, and resource nationalism.

Extreme environments are at the front line of global climate change, the core unit on climate. Arctic amplification and the thaw of permafrost are both effects of warming and feedbacks that add to it, and the lawsuit brought by Saúl Luciano Lliuya against the German company RWE over a glacial lake above Huaraz shows how people in extreme environments try to make distant emitters pay for loss and damage.

The unit on resource consumption explains the demand that drives mining: lithium, copper and nickel for batteries and the energy transition, and fossil water pumped to grow wheat in Saudi Arabia. Tourism in extreme environments, including last-chance tourism to retreating glaciers and shrinking sea ice, links the option to Leisure, tourism and sport, and irrigation and salinisation link it to Freshwater.

How SL and HL differ

Extreme environments is one of seven options. SL students choose two options and HL students choose three. The content of the option is identical at both levels: every subtopic, case study and skill is studied in the same depth, and nothing on the option’s pages is HL only.

Both levels answer the same Paper 1 question on the option, marked with the same markbands. SL and HL differ only in the number of options studied and in the HL extension units, which HL students take in addition.

Assessment

Extreme environments is examined in Paper 1. For each option studied there is a structured question built on a stimulus, worth 10 marks, followed by one extended answer worth 10 marks, chosen from two. The structured question typically has four parts: (a)(i) and (a)(ii), one mark each, read a value or fact from the stimulus; (b), two marks, asks for an outline of one cause or effect; and (c), three marks plus three, asks for two developed explanations.

Stimuli for this option are often climate graphs, maps of aridity or permafrost, a glacier mass balance graph, photographs or topographic maps of glacial and desert landforms, or data on mining and tourism. Typical short questions ask candidates to read a temperature range or a rainfall total, outline one challenge of building on permafrost or explain how a pingo or a barchan forms. Extended questions usually offer one physical theme, such as the formation of glacial landforms, and one human theme, such as the management of desertification or the power of different stakeholders to extract resources.