This chapter concentrates on the impact that environmental aspects have on investment risks. These are generally referred to as environment-induced economic risks. It shows the most important factor is not so much the scale of risk or the probability of it occurring, but rather its composition. A risk is always present if the actual yield turns out to be different than the expected return. One of the most important factors in characterising environmental risks is the differentiation of risks according to the decision period and their interdependencies. Individual environmental risks are of only minor interest to investors prepared to take a number of different risks at the same time. As far as environmental problems are concerned, all risks are both vertically and horizontally systematic if they impact on each individual period over a long time-frame, and also if their influence extends to many different sectors and regions.