This textbook is written for meteorology and climatology students who require an introduction to the principles and practical consequences of atmospheric radiation but who do not necessarily intend to become specialists in radiation or remote sensing. Its objective is to foster an understanding of "how radiation works" and to provide a solid conceptual and mathematical foundation for further study.The author introduces new material in a progressive, logical sequence, starting with simple real-world problems in radiative transfer and adding depth and sophistication with each subsequent chapter. Wherever possible, radiative transfer concepts are illustrated with examples taken from everyday experience. Exercises are interspersed throughout each chapter and are designed to directly reinforce the immediately preceding material. This book is intended for use at both the undergraduate and beginning graduate level. Chapters and sections containing more advanced material are marked as such and may be skipped without loss of continuity.