Global environmental change is increasingly affecting ecosystems and the communities who rely on them. However, more work is needed to conceptualise and quantify migration responses to the impact of environmental change and degradation.This paper argues that reflecting on the manner in which the environment changes can help provide insights into the different mechanisms by which humans respond and adapt to environmental stress. However, it is noted that determining the extent to which environmental stress forces people to move is complex for at least two reasons:

deciphering which of the several push and pull factors influence a decision to migrate is difficult as multiple factors (e.g. social, political and economic factors) often act simultaneously
environmental degradation processes are often a consequence of the degradation of social, economic and political conditions and vice versa.

The authors argue that considering the concept of social-ecological systems and the notion of ecosystem services is useful for understanding this complexity and can help to determine the extent to which ecosystem degradation plays a role in forcing people to migrate. The paper presents a decision framework for categorising people moving due to environmental stress and examines the circumstances leading to a decision to move, including the state of the environment and coping capacities or adaptive abilities of those individuals or communities affected. The authors hope that, following in-depth discussions and improvements of such a framework, it will become a useful tool for operational agencies that have to provide support to people who are displaced or migrate due to environmental stresses.