The Amazon is the world's largest tropical rainforest, covering 5.5 million km² across nine South American countries, with 60 per cent in Brazil. It contains roughly 10 per cent of all Earth's species and stores billions of tonnes of carbon — yet deforestation is destroying it at an alarming rate.
Where is the Amazon and what makes it unique?
The Amazon basin — the drainage area of the Amazon River and its tributaries — straddles the equator in South America, spanning Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana. The River Amazon is approximately 6,400 km long and carries more water than any other river on Earth — about 20 per cent of all fresh water discharged into the world's oceans.
The Amazon's extraordinary biodiversity reflects millions of years of relatively stable tropical conditions. Current estimates include:
- More than 40,000 plant species
- Over 1,300 bird species
- More than 3,000 fish species (more than the entire Atlantic Ocean)
- At least 430 mammal species
- More than 2.5 million insect species
Many of these species are endemic — found nowhere else on Earth. The forest also contains over 400 indigenous tribes, of which approximately 70 have had no contact with the outside world.
What are the layers of the Amazon rainforest?
Tropical rainforests are stratified into distinct vertical layers, each with its own climate, species, and ecological role.
| Layer | Height | Key characteristics |
|---|---|---|
| Emergent layer | 40–60 m | Tallest trees emerge above the canopy; exposed to full sunlight, high temperatures, and strong winds; home to eagles, butterflies, bats, and monkeys |
| Canopy | 25–40 m | Dense, continuous layer of leaves and branches; captures 80% of sunlight; enormous biodiversity; home to most birds, primates, and epiphytes (plants growing on trees) |
| Understorey | 5–25 m | Dimly lit (only about 5% of sunlight reaches here); smaller trees, palms, and shrubs; habitat for jaguars, snakes, and many insects |
| Forest floor | 0–5 m | Very dark; little sunlight; rapid decomposition of leaf litter by fungi and bacteria; home to larger animals and plants adapted to very low light |
The layered structure creates thousands of distinct ecological niches, explaining the exceptional biodiversity. The canopy acts as an enormous roof that intercepts rainfall, reducing the intensity with which water hits the forest floor and reducing soil erosion.
What is the water cycle's relationship to the Amazon?
The Amazon rainforest has a profound two-way relationship with the regional water cycle. Trees absorb groundwater through their roots and release it as water vapour from their leaves — a process called transpiration. The Amazon's trees collectively release approximately 20 billion tonnes of water vapour per day, creating "flying rivers" of moist air that travel thousands of kilometres and deliver rainfall to agricultural areas as far away as southern Brazil, Bolivia, and Argentina.
This makes the Amazon a critical piece of continental infrastructure: the agricultural systems of much of South America depend on the rainfall generated by the Amazon. Scientists have identified an alarming feedback loop: as the Amazon is cleared, the amount of moisture recycled into rain decreases, making the remaining forest drier and more vulnerable to fire and further dieback.
Why is the Amazon being deforested?
Deforestation of the Amazon — the clearing of forest for other land uses — is driven by several interconnected economic, social, political, and environmental forces. Understanding these through the SEEP framework helps explain why deforestation is so difficult to stop.
Economic: Cattle ranching is the single largest driver of Amazon deforestation, responsible for an estimated 70–80 per cent of cleared land. Brazilian beef and leather are exported globally. Soya farming (primarily for animal feed for European and Chinese livestock) is the second largest driver. Large-scale commercial agriculture is far more profitable per hectare than leaving forest standing.
Social: Landless peasants and small farmers clear forest for subsistence farming — a pattern driven by extreme land inequality in Brazil, where a small number of large landowners hold most agricultural land.
Economic (infrastructure): Major infrastructure projects — roads, hydroelectric dams — open up previously inaccessible areas to settlement and logging.
Political: Enforcement of environmental protection laws has been inconsistent, varying significantly with the political priorities of the government in power. Under President Bolsonaro (2019–2022), Amazon deforestation rates reached their highest levels since 2008. President Lula (from 2023) pledged to reach zero deforestation by 2030 and has significantly increased enforcement activity.
What are the consequences of deforestation?
The SEEP consequences of Amazon deforestation are severe and globally significant.
Environmental: The Amazon stores an estimated 150–200 billion tonnes of carbon in trees, soil, and vegetation. Burning or clearing forest releases this carbon as CO₂, contributing significantly to climate change. Loss of habitat drives species extinction — many species not yet identified by science may be lost before they are ever described. The water cycle disruption described above threatens agricultural productivity across South America. Scientists warn of a potential "tipping point" at which cumulative deforestation (estimated at 20–25 per cent of original forest cover) triggers widespread Amazon dieback — an irreversible transition from rainforest to a drier savanna ecosystem.
Social: Indigenous communities who have lived in the Amazon for thousands of years face loss of their land, culture, and livelihoods. Violence against indigenous leaders defending their land has been well documented.
Economic: Some deforestation generates short-term economic gain (from beef, soya, timber). However, the Amazon's ecological services — carbon storage, rainfall generation, biodiversity, genetic resources for medicine — have been estimated to be worth far more than the income from cleared land.
Frequently asked questions
What percentage of the Amazon has been deforested?
As of the early 2020s, approximately 17–20 per cent of the Amazon's original extent has been deforested — primarily in the Brazilian "arc of deforestation" in the south and east of the Amazon basin. A further 10–15 per cent has been significantly degraded by fire, selective logging, and fragmentation without complete clearance. Scientists who have modelled the Amazon's resilience suggest a tipping point may be triggered at around 20–25 per cent clearance, beyond which widespread dieback could occur regardless of future conservation efforts, though the exact threshold is debated.
What is being done to protect the Amazon?
Conservation efforts include: protected areas and indigenous territories (which together cover approximately 40 per cent of the Brazilian Amazon, and deforestation rates within them are substantially lower than outside); satellite monitoring systems (Brazil's PRODES and DETER systems track deforestation in near real-time); the REDD+ international mechanism (Reducing Emissions from Deforestation and forest Degradation), which pays countries to keep forests standing; consumer-country pressure on supply chains to eliminate deforestation-linked products from imports; and the work of indigenous communities themselves, who are consistently shown to be the most effective guardians of forest areas they control.
Why is the Amazon sometimes called the "lungs of the Earth"?
The phrase is common but somewhat misleading. The Amazon's trees absorb large amounts of CO₂ through photosynthesis, which contributed to the "lungs" metaphor. However, a healthy intact forest produces roughly as much CO₂ through decomposition and animal respiration as it absorbs — making it approximately carbon neutral in normal conditions. Where the Amazon is uniquely valuable is as a carbon store: the hundreds of billions of tonnes of carbon locked in its trees and soils, which would be released if the forest were cleared. When deforested areas are set on fire, the Amazon becomes a significant net carbon emitter — the opposite of a "lung."
How does the Amazon affect the UK's climate and environment?
The Amazon is connected to the UK's environment in several ways. As a major carbon store, its deforestation contributes to global greenhouse gas concentrations that drive climate change — including the wetter winters and more extreme rainfall events increasingly experienced in the UK. The Amazon's biodiversity is a source of pharmaceutical compounds, many of which underpin medicines used in the NHS. The UK imports Brazilian soya (for animal feed) and beef (as an ingredient in processed foods), making British consumers and food companies part of the supply chain linked to Amazon deforestation. Post-Brexit, the UK has been working on due diligence legislation to prevent UK supply chains from being linked to illegal deforestation.
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