Tropical rainforest deforestation

CCEA Unit 2 requires a case study of a major environmental issue. The tropical rainforest is the most commonly chosen — students must understand why deforestation happens, what its consequences are, and how it can be managed sustainably.

The tropical rainforest

Location: mainly within 10° north and south of the Equator. The Amazon Basin (South America), the Congo Basin (Africa), South-East Asia (Indonesia, Malaysia, Borneo), and parts of West Africa.

Characteristics:

• High temperature (25-30°C year-round) and very high rainfall (2,000-4,000 mm/year) — ideal for plant growth.
• Highest biodiversity on Earth: although tropical rainforests cover only 6% of Earth's surface, they are home to over 50% of all plant and animal species.
• Complex layered structure: emergent layer, canopy, understorey, and forest floor.
• Nutrient cycling: the soil is actually surprisingly thin and poor — most nutrients are locked in the living vegetation (unlike temperate soils). When trees are removed, nutrients are quickly washed out by rain (leaching).

Amazon rainforest — key facts

• Covers approximately 5.5 million km² across 9 countries (mainly Brazil).
• Contains 10% of all species on Earth.
• Generates approximately 20% of the world's freshwater discharge.
• Acts as a massive carbon store: the Amazon stores approximately 100 billion tonnes of carbon (equivalent to 10 years of current global CO₂ emissions).
• Produces "flying rivers" — transpired moisture that drives rainfall patterns across South America.

Causes of deforestation

Cattle ranching and agriculture (dominant): the greatest driver of Amazon deforestation. Brazil has the world's largest beef export industry. Trees are burned to create pasture — a cheap way to establish ranches on public or indigenous land. Soy farming (for animal feed and biofuels) is also a major driver.

Logging: selective and illegal logging for hardwoods (mahogany, teak) is highly profitable. Legal and illegal logging both contribute.

Mining: Amazon gold, iron ore, and bauxite deposits attract large-scale mining operations that require road construction (opening up previously inaccessible forest to further deforestation).

Hydroelectric dams: Brazil has built multiple large dams in the Amazon (Belo Monte dam on the Xingu River, completed 2016). Reservoirs flood large areas of forest.

Settlement: the Brazilian government historically encouraged poor families to settle in the Amazon (land reform). Deforestation followed road construction.

Scale: Brazil lost approximately 400,000 km² of Amazon rainforest between 2000 and 2020. The rate fell significantly from 2004-2012 under stricter monitoring, but increased again from 2018-2022 under the Bolsonaro government. Since 2023 (Lula government), Amazon deforestation has fallen sharply again.

Consequences of deforestation

Biodiversity loss: many species become extinct before being discovered. The Amazon is estimated to lose 50+ species per day due to habitat destruction.

Climate change: trees store carbon. Burning and decomposition releases CO₂. Amazon deforestation contributes approximately 5% of global CO₂ emissions annually.

Disruption of the hydrological cycle: the Amazon's "flying rivers" (water transpired by trees) drive rainfall across South America. Deforestation reduces transpiration → drier conditions downwind → savannification (the Amazon gradually turning into savanna grassland). Scientists warn of an Amazon tipping point — possibly as soon as 20-25% total deforestation — beyond which the feedback becomes self-sustaining.

Loss of indigenous cultures: approximately 400+ distinct indigenous groups live in the Amazon. Deforestation and associated colonisation threaten their territory, health, and way of life.

Soil degradation: once vegetation is removed, tropical soils rapidly lose nutrients through leaching → land becomes unproductive within a few years → farmers clear more forest → a cycle of ever-expanding deforestation.

Sustainable management strategies

REDD+ (Reducing Emissions from Deforestation and Forest Degradation): an international framework that pays developing countries to protect their forests (a payment for ecosystem services model). Brazil has received significant REDD+ funding.

Protected areas and national parks: the Amazon has numerous national parks and indigenous reserves. FUNAI (Brazil's indigenous affairs agency) recognises indigenous territories.

Debt-for-nature swaps: a country's foreign debt is reduced in exchange for protecting a forested area.

Sustainable forest management: selective logging with replanting; certification schemes (FSC — Forest Stewardship Council) ensure timber comes from sustainably managed sources.

Satellite monitoring (PRODES/DETER system): Brazil uses satellite data to detect and map deforestation in near-real-time. Alerts are sent to enforcement agencies. Has been effective when political will exists.

Agroforestry: integrating trees with crops and livestock. Maintains some forest cover and biodiversity while allowing economic use.