Amazon rainforest

The Amazon rainforest is the largest tropical rainforest in the world, covering a vast area of the Amazon River basin in South America. Most of it lies within Brazil, with significant portions in Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. It is one of the most biologically rich regions on the planet and a major influence on the global climate.

Often called the "lungs of the Earth," a phrase that oversimplifies its role, the forest is better understood as a huge store of carbon and a driver of rainfall and weather patterns across and beyond the continent.

Extent and environment

The rainforest covers several million square kilometres, an area comparable in size to the entire continental United States minus Alaska, or roughly the whole of Australia. The Amazon River, which drains the basin, is the largest river system in the world by volume of water and among the longest by length.

The climate is hot and humid throughout the year, with heavy rainfall and little seasonal temperature variation. This stable warmth and moisture support an extraordinary density of life in every layer of the forest, from the shaded floor to the emergent treetops.

Biodiversity

The Amazon hosts an estimated one in ten of all known species on Earth. It contains countless species of plants, insects, birds, fish, amphibians, reptiles and mammals, many found nowhere else. Its rivers and flooded forests are especially rich, holding an enormous diversity of freshwater fish. For scientists, the region is a living laboratory for ecology and evolution.

People and cultures

The forest has been home to Indigenous peoples for thousands of years. Hundreds of distinct groups live in the region, speaking many languages and maintaining deep knowledge of forest plants, animals and ecology. Some groups remain in voluntary isolation. Indigenous territories, where recognized and protected, often have lower rates of deforestation than surrounding areas.

Beyond Indigenous communities, the Amazon is also home to river-dwelling and urban populations whose livelihoods depend on fishing, farming, and harvesting forest products such as rubber, fruits and nuts.

Deforestation and threats

Large-scale deforestation has been driven by cattle ranching, soy farming, logging, mining, road building and land speculation. Forests are also degraded by fires, many set deliberately to clear land, and by drought, which makes the forest more vulnerable. Scientists warn that continued loss could push parts of the Amazon toward a tipping point, where the forest could not sustain the rainfall it generates and would shift toward drier savanna.

Because the trees store vast amounts of carbon, clearing them releases greenhouse gases and accelerates climate change. This connects the fate of the Amazon directly to global climate goals.

Protection and debate

Efforts to protect the forest include national parks, protected areas and Indigenous lands, international agreements and monitoring systems that track clearing by satellite. Enforcement varies, and deforestation rates have risen and fallen over the decades in response to policy, economic pressures and political will. Balancing economic development with conservation is a central and difficult debate.

Carbon and the water cycle

The forest works as a vast carbon sink, absorbing carbon dioxide from the atmosphere and storing it in living trees, soils and roots. When trees are cut or burned, much of that carbon returns to the atmosphere, which is why deforestation is a major contributor to climate change. Protecting standing forest is therefore also a climate strategy.

The Amazon also drives its own weather. Trees release water vapour through their leaves, a process called transpiration, which helps create the rainfall that sustains the forest. This recycling of moisture means the region can generate what are sometimes called flying rivers, streams of atmospheric water that influence rainfall far beyond the basin, including in farming regions to the south.

Inside the forest

Tropical rainforests are structured in layers. A dark, humid floor receives little light; a dense understory and canopy follow; and scattered emergent trees rise above them. This vertical structure creates countless niches, so different species occupy different heights and conditions. Many plants depend on animals for pollination and seed dispersal, and some trees rely on a single bird or mammal species.

The rivers themselves are also diverse ecosystems. Seasonal flooding creates flooded forests where fish swim among tree roots, and the nutrient-poor black-water rivers differ sharply from the sediment-rich white-water rivers, each supporting distinct life.

Common misconceptions

The Amazon is often imagined as untouched wilderness, but much of it has been shaped by human activity over millennia. It does not produce most of the world's oxygen; the oceans generate far more, and much of the forest's own oxygen is consumed by the forest itself. Its real global importance lies in carbon storage, biodiversity and the water cycle.

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