This textbook discusses environmental and natural resource economics. It presents foundational knowledge for applying economics to understand environmental economics as well as for managing environmental problems and optimizing the level of natural resource extraction. Environmental and Natural Resource Economics bridges knowledge between the major natural environmental issues and which economic policies could be applied for reducing human impacts on such issues. It is distinctive from other environmental economics textbooks by covering not only basic concepts introduced in environmental economics but also explains economic models developed in resource economics for optimizing the use of non-renewable and renewable resources for sustainability. This textbook will help students understand how to apply economics for utilizing policies to mitigate environmental issues caused from the output side of economic activities such as emitting pollutants or generating wastes and those derived from the input side such as natural resource extractions.