This book covers topics related to climate change, weather, greenhouse effect, solar energy, various cycles including carbon, hydraulic, sulphur, renewable energy conservation, ecology and sustainable environment. The contents of the book include pedagogical elements, such as exercises, tables and figures at appropriate places in each chapter, including problems and objective questions at end of each chapter, to aid in learning. Further, the unit conversion from FPS system to SI unit of each parameter, namely length, energy, power, velocity and pressure force, etc, and some standard constants used in examples are also provided in the book. The book also includes discussion about renewable energy sources, namely solar energy, wind energy, biomass energy and geothermal energy, etc, their availability and eco-friendly nature. This book can be a useful reference for those in academia and industry.