Unveiling hidden migration and mobility patterns in climate stressed regions: A longitudinal study of six million anonymous mobile phone users in Bangladesh

Xin Lu, David J. WrathallPål Roe Sundsøy, Md. NadiruzzamanErik WetterAsif IqbalTaimur QureshiAndrew TatemGeoffrey CanrightKenth Engø-MonsenLinus Bengtsson

Current data on climate-induced migration is derived exclusively from household surveys but there exist difficulties in both the actual collection of data, the size and causal mechanisms behind, but also in attributing individual migration events to climate change.

Limitations of household surveys include that analysis requires detailed mobility data over a range of temporal and spatial scales, biased interviews from family households, logistical difficulties of data collection. This results in that not all surveys are performed at the same time, which may bias results, and collection of data from migrating households are often spread across large areas.

To understand the link between climate change, changing living conditions and migration, traditional surveys must be replaced by analysis longitudinal studies over several years to observe changes. One potential data source that can fulfil these requirements is the call detail record (CDR). CDR has been used previously for quantifying the spread of infectious diseases for example and collects data including information on the position of the mobile through calls, texts and data download. The mobile network operators then store the data.

Studies using CDR has been carried out in Bangladesh, highly vulnerable to extreme weather events, and shows that CDR is a very promising data source as a supplement to existing household surveys which allows us to monitor, interpret and respond to climate-induced migration patterns both on local and national scales.

6059184704_eb86b6a296_zImage credit: eGuide Travel (CC BY 2.0) from Flickr.com

Chanelle Andrén is a volunteer at UK Climate Change and Migration Coalition and writes the round up of new research on climate change, migration and displacement. Her background is in International Human Rights Law with specialisation in ‘Just Transitions’.