This book is a detailed exploration of the working practices of a community of scientists exposed in public, and of the making of scientific knowledge about climate change in Scotland. For four years, the author joined these scientists in their sampling expeditions into the Caledonian forests, observed their efforts in the laboratory to produce data from wood samples and followed their discussions of a graph showing the evolution of the Scottish temperature over the past millennium in conferences, workshops and peer-review journals. This epistemography of climate change is of broad social and academic relevance - both for its contextualised treatment of a key contemporary science, and for its original formulation of a methodology for investigating expertise. -- .