The Amazon basin covers 2.7 million square miles across nine countries - 60% in Brazil. The rainforest itself spans 2.1 million square miles, making it the largest tropical forest on Earth. The Amazon River discharges more water than the next seven largest rivers combined.

Approximately 390 billion individual trees grow in the Amazon, representing 16,000 species. Scientists estimate 10% of all species on Earth live here - including 2.5 million insect species, 40,000 plant species, and 3,000 fish species. New species are discovered regularly. Many will go extinct before being catalogued.

The Amazon generates half its own rainfall. Trees pump water from the soil through their roots and release it as vapor through their leaves - transpiration. This moisture forms clouds that rain back down. The process creates 'flying rivers' of atmospheric moisture that water the forest and regions far beyond.

Without the forest, rainfall would collapse. Climate models suggest deforestation past a certain threshold - perhaps 20-25% - could trigger a 'tipping point' where the forest can no longer sustain itself. The Amazon would gradually become savanna. That threshold may be approaching.

An estimated 400-500 indigenous groups live in the Amazon, totaling about 1 million people. Many have had no contact with the outside world - Brazil's FUNAI agency monitors approximately 100 uncontacted tribes. They live as their ancestors did, hunting, fishing, and farming small plots.

First contact with isolated tribes is often fatal - they lack immunity to common diseases. Some tribes actively resist contact, attacking helicopters and intruders with arrows. They've learned that outsiders bring death. The Amazon is one of the last places on Earth where humans live as they did 10,000 years ago.

Approximately 17% of the Amazon has been destroyed since 1970 - mostly for cattle ranching (80%) and soy farming. Deforestation rates fluctuate with political will: Brazil reduced destruction 80% between 2004 and 2012, then allowed it to surge again after 2019.

Fires, often set illegally to clear land, have become more frequent and severe. The 2019 fire season saw 80,000 fires burn simultaneously. Smoke darkened Sao Paulo's skies 1,700 miles away. The forest that creates its own rain increasingly burns in its own drought.

The Amazon stores 150-200 billion tons of carbon. If released through deforestation and fire, that carbon would accelerate climate change catastrophically. The forest that helps regulate global climate could, if destroyed, tip the planet into runaway warming.

Conservationists fight to preserve what remains. Indigenous communities protect their territories. International pressure fluctuates with politics. The outcome is uncertain. The Amazon has existed for 55 million years. Whether it exists in 2100 depends on decisions made in the next few decades. The lungs of the Earth are struggling to breathe.