Gases that absorb and emit radiant energy within the infrared range and thus cause the greenhouse effect are called greenhouse gases. Carbon dioxide, water vapor, methane, ozone and nitrous oxide are the primary greenhouse gases present in the Earth's atmosphere. The average temperature of the Earth's surface would have been considerably lesser than the present average temperature without the greenhouse gases. Their concentration in the atmosphere is determined through a balance between sources and sinks. These gases are also present in the atmospheres of Mars, Venus and Titan. There has been significant increase in the concentration of carbon dioxide in the Earth's atmosphere due to human activities since the beginning of the Industrial Revolution. This book unravels the recent studies in the field of greenhouse gases. It aims to shed light on some of the unexplored aspects and the recent researches in this field. This book is a vital tool for all researching or studying greenhouse gases.