This is the first major textbook to encompass the true complexity of climate change. While greenhouse warming dominates most of the literature, Bryant presents numerous reasons for the observed climate change of the past century. He argues that changes in climate, more dramatic than those of the past 150 years, have been a predominant aspect of the Earth's climate over the past two million years. He highlights human impacts on climate other than "greenhouse" gases, including sulphate air pollutants, dust and urban heat islands. He also explains the natural components forcing climate change. Bryant presents, in simple terms, the processes that drive the Earth's present climate system. He outlines the nature and reasons for temperature fluctuations over millennia, including recent human-induced climate change. Finally, he discusses the impact of climate change on human health and the world's ecosystems. This text will be an invaluable resource for undergraduate students as well as a reference for professionals.