Human activities affect the operation of physical environment processes, and the results rebound on the human world. The human factor is an important consideration in assessing climate, landform, and ecosystem changes. The physical environment provides resources and a platform to use those resources, but can also be a hazard to people. Therefore human impact as a subject is of special concern to physical geographers. This interest has developed from studying the impacts of the environment on human activities, to understanding the impacts of humans on the environment and attempting to reduce them. There is now overt recognition of the role of the human factor, wh ich is also reflected in an increase in applied work by physical geographers. The effects of human activit ies and physical environmental modifica tions range from being entirely local to global, and can be immediately evident or they may manifest slowly over time and become of concern at some time in the fu ture. The duration of the effects can be short-lived or everlasting. Many examples can be observed in our surrounding landscape. While this chapter describes and discusses only some of the impact of human presence in New Zealand, the conceptual context of humans as agents of environmental change is woven into the examples given.