Claims have been made that global environmental change could drive anywhere from 50 to almost 700 million people to migrate by 2050. These claims belie the complexity of the multi-causal relationship between coupled social-ecological systems and human mobility, yet they have fueled the debate about "environmentally induced migration". Empirical evidence, notably from a 23 case study scoping study supported by the European Commission, confirms that currently environmental factors are one of many variables driving migration. Fieldwork reveals a multifaceted landscape of patterns and contexts for migration linked to rapid- and slow-onset environmental change today. Migration and displacement are part of a spectrum of possible responses to environmental change. Some forms of environmentally induced migration may be adaptive, while other forms of forced migration and displacement may indicate a failure of the social-ecological system to adapt. This diversity of migration potentials linked to environmental change presents challenges to institutions and policies not designed to cope with the impacts of complex causality, surprises and uncertainty about social-ecological thresholds, and the possibility of environmental and migration patterns recombining into a new patterns. The paper highlights fieldwork on rapid- and slow-onset environmentally induced migration in Mozambique, Vietnam, and Egypt. Current governance frameworks for human mobility are partially equipped to manage new forms of human mobility, but that new complementary modes of governance will be necessary. The paper concludes with challenges for governance of environmentally induced migration under increasing complexity, as well as opportunities to enhance resilience of both migrants and those who remain behind. (C) 2009 Elsevier Ltd. All rights reserved.
