AQA GCSE Geography (8035) — Living with the physical environment
You can easily spot a single missing tree in a local park, but in the Amazon, an area the size of a small country has vanished. Since 1970, approximately 20% of the Brazilian Amazon has been deforested. The Amazon is the world's largest tropical rainforest, and 60% of it lies within Brazil, which is classified as a Newly Emerging Economy (NEE).
Deforestation is driven by several competing human activities. The leading cause is commercial farming for cattle, accounting for 63% to 80% of forest loss as Brazil exports over $6bn of beef annually. Crop farming is another massive driver; in the Mato Grosso region, 43% of forest loss was replaced by grain (like soybeans for animal feed) and cattle.
Other significant causes include:
These causes are highly interdependent. The Trans-Amazonian Highway (a 4,000 km road) opened up remote areas. Statistics show that 95% of deforestation occurs within 50 km of a road or navigable river, proving that road building directly enables logging, which in turn clears land for farming.
Did you know that the soil in a lush tropical rainforest is actually incredibly poor in nutrients? The soil, known as , relies entirely on rapid to support plant life. When trees are removed, heavy rainfall causes , washing the few remaining nutrients away.
Without tree roots to bind the earth, Brazil loses 55 million tons of topsoil annually to soil erosion. This eroded soil washes into rivers, causing siltation that reduces water capacity and significantly increases the local flood risk.
The Amazon normally acts as the "Lungs of the Planet" through carbon sequestration, storing 100 billion tonnes of carbon and absorbing 2 billion tonnes of CO₂ annually (5% of global emissions). Deforestation turns this carbon sink into a carbon source, with parts of the eastern Amazon now emitting more CO₂ than they absorb. Locally, the lack of trees reduces evapotranspiration, which has caused rainfall to decline by 20% and temperatures to rise by 1.5°C in deforested areas.
Finally, the rainforest holds 20% of Earth's species, resulting in immense biodiversity. Deforestation destroys these habitats, causing an estimated loss of 137 species every single day. This also threatens human health, as 25% of Western medicines (like Reserpine for blood pressure) originate from rainforest plants.
Why would a country destroy its most famous natural environment? The simple answer is rapid economic development. Activities in deforested areas account for roughly 25% of Brazil's GDP.
Large-scale projects like the Carajás Mine generate massive export wealth, such as $28bn in metals exported in 2018 alone. This triggers a powerful multiplier effect:
However, these short-term economic gains must be weighed against long-term economic losses. Deforestation destroys the sustainable tourism industry and eliminates the chance to discover highly profitable future medical resources. Furthermore, the costs of managing climate change and extreme weather events (like flooding from silted rivers) will place a heavy financial burden on the country's future.
In exams, you may be asked to calculate the average rate of deforestation over a specific period. You can find the mean forest loss per year using the following formula:
Worked Example:
If 163.8 million hectares of forest were lost over a 7-year period, what is the mean loss per year?
Step 1: Identify your values.
Step 2: Substitute into the formula.
Step 3: Calculate the final answer with units.
Students often assume rainforest soil is incredibly fertile because the vegetation is so lush. Correct answer: The soil (latosol) is actually nutrient-poor; fertility relies entirely on the rapid nutrient cycle, which breaks down when trees are removed.
In 9-mark 'Evaluate' questions, examiners expect a balanced argument weighing the economic benefits (like GDP growth and the multiplier effect) against the severe environmental costs (biodiversity loss and climate change).
Always explicitly name 'The Amazon, Brazil' in your answers rather than just saying 'the rainforest' to secure your case study marks.
When explaining the causes of deforestation, highlight the interdependence between activities; for example, explain how road building enables logging, which in turn clears land for cattle ranching.
Newly Emerging Economy (NEE)
A country that has begun to experience high rates of economic development, usually with rapid industrialisation.
Commercial farming
Large-scale farming for profit, such as cattle ranching or soybean plantations.
Subsistence farming
Small-scale farming where crops are grown primarily to feed the farmer's own family.
Slash and burn
Cutting and burning vegetation to create a nutrient-rich layer of ash for temporary cultivation.
Selective logging
Removing only highly valuable tree species (like Mahogany) while leaving the rest of the forest intact.
Latosol
The nutrient-poor, acidic, red-coloured soil typical of tropical rainforests.
Nutrient cycling
The rapid transfer of nutrients between biomass (trees), litter (dead leaves), and soil.
Leaching
The process where heavy rainfall washes minerals and nutrients out of the soil, leaving it infertile.
Carbon sequestration
The process of capturing and storing atmospheric CO₂ in solid form, such as within the wood of trees.
Biodiversity
The variety of plant and animal life in a particular habitat.
Multiplier effect
When an initial investment (e.g., a mine) creates additional jobs and wealth in the local economy.
Put your knowledge into practice — try past paper questions for Geography
Newly Emerging Economy (NEE)
A country that has begun to experience high rates of economic development, usually with rapid industrialisation.
Commercial farming
Large-scale farming for profit, such as cattle ranching or soybean plantations.
Subsistence farming
Small-scale farming where crops are grown primarily to feed the farmer's own family.
Slash and burn
Cutting and burning vegetation to create a nutrient-rich layer of ash for temporary cultivation.
Selective logging
Removing only highly valuable tree species (like Mahogany) while leaving the rest of the forest intact.
Latosol
The nutrient-poor, acidic, red-coloured soil typical of tropical rainforests.
Nutrient cycling
The rapid transfer of nutrients between biomass (trees), litter (dead leaves), and soil.
Leaching
The process where heavy rainfall washes minerals and nutrients out of the soil, leaving it infertile.
Carbon sequestration
The process of capturing and storing atmospheric CO₂ in solid form, such as within the wood of trees.
Biodiversity
The variety of plant and animal life in a particular habitat.
Multiplier effect
When an initial investment (e.g., a mine) creates additional jobs and wealth in the local economy.
