The atmosphere is the thin, diffuse fluid that envelops the Earth’s surface. Despite its apparent fragility, the existence of this fluid is vital for human and other life on Earth. The Atmosphere: A Very Short Introduction describes the physical and chemical characteristics of different layers in the atmosphere, and shows how the atmosphere’s interactions with land, ocean, and ice affect these properties. It also looks at how movement in the atmosphere, driven by heat from the Sun, transports heat from lower latitudes to higher latitudes. Finally, it presents an overview of the types of measurements used to understand different parts of the atmosphere, and identifies future challenges in the light of climate change.