The author, Dr. S. Niranjan is an eminent faculty for UPSC Civil Services Examination. He has been imparting training to aspirants of Civil Services Examination conducted by the UPSC and State PSCs for the last 15 years. He has guided numerous aspirants to success in Civil Services Examination owing to his skills in simplifying the conceptual topics and predictive acumen regarding pattern of questions in the exams each year. The ease with which he handles the nuances and complexities of varied topics in Environment and Ecology has given him the recognition as one of the most popular teachers of the subject.