The Amazon is the biggest tropical rainforest in the world. It's home to more than three million species of plants and animals, as well as a million tribespeople who live there. The rainforest is also a vital defence against climate change, fighting carbon dioxide levels and global warming. In a typical year, the Amazon absorbs around 1.5 gigatons of carbon dioxide from our atmosphere.

(Adapted from: https://www.bbc.co.uk/newsround/49435987)

In the Text, the phrase “The Amazon is the biggest tropical rainforest in the world” means that: