Topic modelling exposes disciplinary divergence in research on the nexus between human mobility and the environment

Kerstin K Zander,Barbora Šedová,Stephen T Garnett,Hunter S Baggen,Sonja Ayeb-Karlsson,Carmen Richerzhagen,Hermann Lotze-Campen,Harald Sterly

doi:10.1057/s41599-022-01038-2

Abstract

Human mobility is increasingly associated with environmental and climatic factors. One way to explore how mobility and the environment are linked is to review the research on different aspects of the topic. However, so many relevant articles are published that analysis of the literature using conventional techniques is becoming prohibitively arduous. To overcome this constraint, we have applied automated textual analysis. Using unsupervised topic modelling on 3197 peer-reviewed articles on the nexus between mobility and the environment published over the last 30 years, we identify 37 major topics. Based on their language use, the topics were deeply branched into two categories of focus: Impact and Adaptation. The Impact theme is further clustered into sub-themes on vulnerability and residential mobility, while articles within the Adaptation theme are clustered into governance, disaster management and farming. The analysis revealed opportunities for greater collaboration within environmental mobility research, particularly improved integration of adaptation and impact research. The topic analysis also revealed that, in the last 30 years, very little research appears to have been undertaken in migration destinations or on the fate of environmentally influenced migrants during their migration process and after arriving in a new location. There are also research gaps in gender and Indigenous issues within the Impact theme, as well as on adaptive capacity and capacity-building.

Highlights

Never have humans been so mobile (IOM, 2020), notwithstanding what is expected to have been a temporary hiatus in 2020/21
Based on four algorithms, we used a latent Dirichlet allocation (LDA) model to categorise the texts of the 3197 articles into 37 topics (Fig S2 in Supplementary Materials), which we summarised using a small set of distinct key words (Table 2) out of the most important 50 words
The three most frequent topics, none more than 5% of topics, were drought adaptation of farmers, climate change adaptation policy and concepts of environmental and climate change migration

Summary

Introduction

Never have humans been so mobile (IOM, 2020), notwithstanding what is expected to have been a temporary hiatus in 2020/21. Climate change and environmental degradation can influence all these types of mobility to different degrees, even where they are not the major drivers (Black et al, 2011, 2013; Hermans and McLeman, 2021). Reviews of the literature on environmental and climate mobility, including recent meta-analyses, have largely focused on climate as a push factor for the migration decisions of vulnerable people (Cattaneo et al, 2019; Hoffmann et al, 2021; Kaczan and Orgill-Meyer, 2020; Piguet et al, 2018). Hoffmann et al (2020) undertook a meta-analysis of 30 case studies to quantify the influence of different environmental factors on migration, Beine and Jeusette (2021)—a meta-analysis on 51 empirical studies to investigate methods applied to link climate change to migration and Šedová et al (2021)—meta-analysis using 116 studies to reveal establish causes for climate migration. Other reviews tend to have concentrated on specific regions (Borderon et al, 2019; Piguet et al, 2018; Thalheimer et al, 2021) or on international migration (Obokata et al, 2014). Thompson et al (2017) reviewed literature on disaster evacuation

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Discussion

Conclusion