Natural Gas: Economics and Environment is the fourth and last book in a series of textbooks that have focused on the technical and market related fundamentals of natural gas, while also taking aspects into consideration that one shared between the oil & gas industry. Volume 4 consists of three additional chapters and commences with chapter 17 dealing with the economic modelling of a natural gas project. The economics of three models are introduced in this chapter, i.e... (1) an upstream E&P project, (2) a LNG model and (3) a gas-to-electricity (CCGT) model. Chapter 18 describes HSEQ (health, safety, environment and control) related aspects in connection with natural gas, with a focus on environmental aspects. Chapter 19 deals with the industrial environment related to the oil and natural gas industry. A historical overview of the development of the techniques used in this industry is provided together with a selective overview of current technological developments. Volume 4 ends with an outlook on future exploration in the quest for oil and gas that has not ended yet. Volume 4 in hand is the last of four volumes on the various aspects of natural gas and the oil and gas industry. The aim of this study - including all of the four volumes - was to enable the reader to acquire sufficient knowledge of the fundaments of the natural gas industry in order to enable him or her to participate in a qualified decision making process. Natural Gas: Economics and Environment is the fourth and last book in a series of textbooks that have focused on the technical and market related fundamentals of natural gas, while also taking aspects into consideration that one shared between the oil & gas industry. Volume 4 consists of three additional chapters and commences with chapter 17 dealing with the economic modelling of a natural gas project. The economics of three models are introduced in this chapter, i.e... (1) an upstream E&P project, (2) a LNG model and (3) a gas-to-electricity (CCGT) model. Chapter 18 describes HSEQ (health, safety, environment and control) related aspects in connection with natural gas, with a focus on environmental aspects. Chapter 19 deals with the industrial environment related to the oil and natural gas industry. A historical overview of the development of the techniques used in this industry is provided together with a selective overview of current technological developments. Volume 4 ends with an outlook on future exploration in the quest for oil and gas that has not ended yet. Volume 4 in hand is the last of four volumes on the various aspects of natural gas and the oil and gas industry. The aim of this study - including all of the four volumes - was to enable the reader to acquire sufficient knowledge of the fundaments of the natural gas industry in order to enable him or her to participate in a qualified decision making process.