Background: Anthropogenic climate change has and will continue to have an increasing impact on human welfare whilst possibly inducing movement of people from environmentally stressed areas within or across national borders. The topic of climate-related migration is becoming a growing concern as effective policy responses, plans for adaptation and investments are yet to be developed. Nevertheless, causal links between climate change and human migrations are often unclear or complex and the notion of a 'climate migrant' is argued to be a social construction. Evidence of climate change-related impacts and extreme weather events on human migration seem to not be synthesised in a systematic manner so far and data on these effects seem to be scattered across multiple sources.

Objectives: We aim to systematically identify and catalogue all available empirical literature on the impact of climate change and extreme weather events on people’s movements (including domestic and international movements, forced displacement, migration, and planned resettlement).

Methods: To describe the state of knowledge on the topic and to identify knowledge gaps, we will use a systematic mapping method that includes: 1) publishing a peer-reviewed protocol of planned methods; 2) a comprehensive search for evidence (including grey and peer-reviewed literature); 3) screening evidence for relevance against predetermined inclusion criteria; 4) extraction of descriptive information (meta-data) and categorisation of studies (coding); 5) assessment of the validity (quality and generalisability) of included evidence; and, 6) generating a systematic map database and reporting of the map findings. A scoping search for literature indicated that the size of the evidence base is moderate (Table 1). Apart from peer-reviewed literature, a significant amount of relevant evidence may be available from the grey literature sources as climate change and migration is an area of work of many international agencies, including the International Organization for Migration and the United Nations High Commission for Refugees.