12.1 covered the drivers and evidence of change. This chapter zooms into the three big changes to Earth's land surface — deforestation, desertification and retreating ice — plus the global response. Green boxes are case/place studies; blue are definitions; orange are exam tips. Pair with the revision slides and activities.
Land cover is what physically covers the ground — forest, grassland, ice, crops, city. Humans are transforming it at a planetary scale.
The alteration of Earth's land surface, largely by human activity — deforestation, agriculture, urbanisation — with major consequences for biodiversity, the carbon cycle and climate.
This chapter follows three interconnected, global-scale land-cover changes, each a case of human–environment interaction:
The clearing of forests — the largest single driver of terrestrial biodiversity loss and a major carbon source.
The permanent clearing and removal of forest to make way for other land uses — agriculture (cattle, soy, palm oil), logging, mining, roads and settlement.
Forests have been cleared for millennia, but the rate has accelerated sharply in recent decades, concentrated in tropical rainforests. Deforestation causes a double environmental blow:
The Amazon holds more than half the world's remaining tropical rainforest and is a vast carbon store. Roughly 17–20% has been cleared, mainly for cattle pasture and soy, plus logging and roads. Scientists warn a tipping point could flip parts of it from rainforest to savanna (dieback).
Illustrates deforestation drivers, the carbon/biodiversity double blow, and a tipping point. Concepts: environment, interconnection, change, sustainability.
EnvironmentInterconnectionSustainabilityCleared-area percentages for the Amazon vary by source and year (~17–20%). Quote it as an approximate range and cite a reputable source (e.g. INPE, Global Forest Watch, WWF).
Land cover change is a global problem, so the response is international. The 2022 UN biodiversity agreement is the headline example.
At the UN Biodiversity Conference (COP15) in Montreal, December 2022, the world's governments — parties to the UN Convention on Biological Diversity (~196) — adopted a framework with 23 targets. Its flagship is “30×30”: protect 30% of the planet's land and oceans by 2030, plus restore degraded ecosystems and cut harmful subsidies.
A verified example of a sustainability response & management strategy at a global scale — ideal for “evaluate the effectiveness” questions. Concepts: sustainability, scale, interconnection.
SustainabilityScaleFor a management strategy, weigh strengths (near-universal agreement, a measurable target) against limits (voluntary, enforcement and funding gaps, “paper parks”). A judgement — how effective, and why — is what lifts the band.
The degradation of dryland into desert-like conditions — a slower, quieter land-cover change affecting over 100 countries.
Land degradation in arid, semi-arid and dry sub-humid areas, driven by human activity and climate variation, causing a persistent loss of biological productivity.
Desertification affects over 100 countries and threatens the food and water security of hundreds of millions of people. It arises from a self-reinforcing cycle:
The Sahel — the semi-arid belt south of the Sahara — faces desertification from drought, overgrazing, fuel-wood collection and rapid population growth. Responses include the Great Green Wall, an ambitious pan-African effort to restore a band of vegetation across the continent.
A verifiable place study of causes, human impacts and a management response. Concepts: environment, interconnection, sustainability, change.
EnvironmentChangeSustainabilityThe clearest visible signature of warming on the land surface — monitored from space.
Glaciers and ice sheets are retreating almost everywhere as the planet warms. This matters because ice is both a freshwater store and a driver of sea-level rise.
As mountain glaciers shrink, the rivers they feed become less reliable, threatening water supply, agriculture and hydropower for downstream communities. Melting land ice (Greenland, Antarctica) adds directly to sea-level rise.
Because polar regions are remote, scientists track ice change with satellite imagery. Studies of Greenland's marine-terminating glaciers (2000–2020) map where ice is lost fastest — data that feeds sea-level projections and policy. This is a live example of spatial technologies as a geographical tool.
Links content to the geographical tool of spatial technologies / remote sensing. Concepts: change, scale, environment.
ChangeScaleTaken together, these changes raise a big question: are there any “natural” systems left?
A proposed geological epoch defined by humans being the dominant influence on Earth's systems — visible in land cover, climate, biodiversity and even sediment layers.
Deforestation, desertification and ice loss are so widespread that scientists argue human activity is now a planetary geological force. That is the case for naming a new epoch, the Anthropocene.
Check you can do these before moving to Chapter 13 (Climate Change).
Part 12 has established land cover change and its climate links. Chapter 13 (Climate Change) now examines climate change in depth — its spatial/temporal characteristics, causes, impacts, and responses (with Costa Rica as a case study).
Everything in this chapter traces to a source you can check. Watch the explainer, read the primary sources, follow the news, and practise the geographical skills this chapter uses.