This survey paper presents the reader with the economics of risk and uncertainty, narrowly focusing on environmental and natural resources problems. Risk involves known, but uncertainty or ambiguity involves unknown, probabilities, or at least a lack of precision about them. Some theoretical review is provided for decision making under both risk and uncertainty, but emphasis is on critically reviewing the newest relevant empirical work. Topics covered include elicitation of risks or subjective probabilities, nonmarket valuation, value of a statistical life, but also optimal extraction of resources. The paper concludes by offering suggestions for future directions of research.