In short

Facts at a glance

A shorter path through the same sourced claims. The full list, and the disagreements, live on the fact-check log.

The forest

A rainforest, in Britannica wording, is a luxuriant forest, generally composed of tall, broad-leaved trees and usually found in wet tropical uplands and lowlands around the Equator. Britannica

There are two types of rainforests, tropical and temperate. Tropical rainforests are found closer to the equator where it is warm. Temperate rainforests are found near the cooler coastal areas further north or south of the equator. NASA

Rainforests usually occur in regions where there is a high annual rainfall of generally more than 1,800 mm (70 inches) and a hot and steamy climate. The trees found in these regions are evergreen. Britannica

Lying either side of the equator, tropical rainforest climates are characterised by high temperatures and year-round rainfall. Met Office

The climate

Average temperatures are usually around 20-30 °C, with minor variation over the year. Met Office

Rainfall is over 60 mm of rain in every month, giving rise to thick rainforest and some of the highest densities of biodiversity seen on land. Met Office

The Intertropical Convergence Zone, or ITCZ, is a band of low pressure around the Earth which generally lies near to the equator. Met Office

NASA says rainforests receive the most rain of all of the biomes in a year, and that a typical year sees 2,000 to 10,000 millimeters (79 to 394 inches) of rain. NASA

Layers

It is known for its dense canopies of vegetation that form three different layers. NASA

The top layer or canopy contains giant trees that grow to heights of 75 m (about 250 ft) or more. This layer of vegetation prevents much of the sunlight from reaching the ground. NASA

Rainforests exhibit a highly vertical stratification in plant and animal development. The highest plant layer, or tree canopy, extends to heights between 30 and 50 metres. Britannica

Contrary to popular belief, the rainforest floor is not impassable. The ground surface is bare, except for a thin layer of humus and fallen leaves. Britannica

Places

Tropical rainforests grow mainly in three regions: the Malesian botanical subkingdom, from Myanmar to Fiji, including Thailand, Malaysia, Indonesia, the Philippines, Papua New Guinea and parts of tropical Australia; tropical South and Central America, especially the Amazon basin; and West and Central Africa. Britannica

The Amazon Basin covers 2,700,000 square miles (7,000,000 square kilometers), making it the largest drainage basin in the world. It occupies more than 40% of South America’s land area, and much of the basin is covered by dense tropical rainforest. NASA JPL

Temperate rainforests filled with evergreen and laurel trees are lower and less dense than other kinds of rainforests because the climate is more equable, with a moderate temperature range and well-distributed annual rainfall. Britannica

Open questions

A NASA Earth Observatory feature dated 31 December 2002, still on the page we checked, says that perhaps as much as one half of all life forms on the planet live in the Amazon River Basin, and later that the region supports perhaps half of all species on the planet. NASA

Ten per cent of the world's biodiversity is thought to exist within this region, in the Met Office's 2024 wording. Met Office

While some recent findings indicate the Amazon rainforest may be close to becoming a source of carbon, it has generally functioned as an enormous carbon sink. NASA

Tropical rainforests today serve as sinks for more than 50 percent of all atmospheric carbon dioxide absorbed by plants annually, and they exhibit unparalleled biodiversity. Britannica