A thin, invisible layer of air surrounds the Earth, sustaining all known life on the planet and creating the unique climates and weather patterns that make each part of the world different, We all know that the atmosphere exists - but how much do we really understand it? What exactly is it? What is it made of, how did it come about and how does it generate the weather patterns and climates that we experience every day? How is scientific research into the atmosphere carried out? And - perhaps most pressingly - what exactly is climate change, according to the actual science? In Firmament, atmospheric scientist and science communicator Simon Clark offers a rare and accessible tour of the ins and outs of the atmosphere and how we know what we know about it, From the workings of its different layers to why carbon dioxide is special, from pioneers like Pascal to the unsung heroes studying climate change today, Firmament introduces us to an oft-overlooked area of science and not only lays the ground work for us to better understand the debates surrounding the climate today, but also provides a glimpse of the future that is possible with this knowledge in hand,