The aim of this article was to understand the relationships between climate change, migration, and food security. Our results identified clear trends towards drying in NW Cambodia, but with variation across districts. Migration affected between a quarter and a half of households surveyed, predominantly driven by climate-related factors, resulting in labour shortages and welfare issues, and coinciding with significantly higher rates of food insecurity. Analyses of food insecurity coping strategies indicate that migration timing is affecting food production systems.
Studies show that climate variations have a significant but non-linear impact on crop yields (Chang 2002). Climate uncertainty is clearly evident in NDVI data variation both between years and between locations. Analysis of historical and projected temperature and rainfall data of Cambodia found that annual mean temperature has increased by 0.8 since 1950 and rainfall is decreasing at the rate of 0.184% per year. These changes suggest that there will be a higher chance of failure in agricultural predictions and planning practices in future. Thus, adaptation strategies that address climate change are likely to be dependent on perceived risk; when uncertainty exists, strategies such as migration may be seen as a mechanism to balance economic losses.
Migration causes and consequences
Our analyses attempt to untangle climate and economic drivers of migration. While migrants were sometimes from larger households, the combination of food insecurity and induced labour shortages indicates that these family members do not represent ‘spare labour’ who migrate to diversify economic risk, as reported in Thailand, Kenya, and Malawi (Ng’ang’a et al. 2016; Suckall et al. 2016; Sakdapolrak et al. 2014). Migrants in this study are ‘displaced’ (Black et al. 2011b; Geddes et al. 2012), providing remittances that address food insecurity and debt.
Climate-related impacts such as bad harvest and agricultural and natural disasters that induce food insecurity and debt explained between two-thirds and all of economic reasons for migration, making ‘climate-related’ factors a key migration driver. While the links between food insecurity and climate change are clear, food insecurity is also affected by skills, knowledge, and assets that enable households to mitigate the impacts of a changing climate on production. The decision for a household member to migrate in any 1 year is unlikely to be limited to just the previous year’s production activity. It may be related to older accumulated debt, not readily identified as ‘climate-related’, or a combination of older and newer problems that cause an economic tipping point to be crossed, resulting in the decision to migrate. In some cases, respondents may identify with a primary reasoning (e.g. lack of money, or food insecurity), but not what led to that situation (e.g. climate or other causes), nor the cumulative effect of climate on other stressors, nor longitudinal cumulative impacts of climate divers. Alternative research methods, for example analyses of landlessness or debt (e.g. Maltoni 2007), face the same problem. Further disaggregation of reasons for migration could be possible with a much larger sample size, increasing statistical power. However, it will still be difficult to separate cumulative and longitudinal relationships between debt and climate. What we have achieved in our analysis is to separate pure financial reasons for migration from those that relate to climate change impacts on existing livelihoods, and we have identified that climate-related factors are the single biggest driver.
Migration rates identified in our study were higher than the figures reported elsewhere (Kingdom of Cambodia 2012; Bylander and Hamilton 2015), but they were similar to those reported from bordering Laos (Manivong et al. 2014). The variation between locations most likely reflects ease of access to the Thai border, 1.5 h from both Lvea Krang and Chamkar Samrong, and until the recentFootnote 1 permeability of this border, where 90% of migrants are reportedly irregular (Maltoni 2007). Migration is not permanent, making migration labour a displaced rather than missing family and community resource. However, this negates consideration of gender-related impacts resulting from predominantly male migrants, i.e. a lack of younger, fitter men to fulfil gender-related roles (Sumner et al. 2017) of land preparation, crop and seed selection, and fertiliser and herbicide application. Thus, migration represents a loss of critical labour from communities that risks exacerbating the effect of climate change rather than remedying it.
Remittances offer a potential means to address loss of labour from a community and ensure that migration is adaptive in the long term. Migrant remittances were only 27–73% of that reported elsewhere (Kingdom of Cambodia 2012), but may go some way towards overcoming a loss of labour associated with displaced migrants. However, reported remittances ($307–834pa) are unlikely to be sufficient to cover labour costs ($292 per ha in 2012 (Van Wensveen et al. 2016), and average agriculture holding size of 2–3 ha (Kingdom of Cambodia 2013)). As OECD (2017) note, in 2014, 40% of remittances are used to pay debt. Thus, migrant displacement would need to avoid critical production events to ensure that migration is an adaptive rather than maladaptive strategy.
Patterns of migration across the year are important given that they influence the ability of a community to avoid impacts on critical production events. In Popok, the co-occurrence of peak migration and rice planting activities explains why migration failed to reduce food insecurity, whereas migration at these times of year in Lvea Krang was at a trough (albeit at a higher rate than in Popok), reducing food insecurity in just over a half of households sampled. The implications for livelihood development are significant, especially given the gendered roles that occur within agriculture production (ADB 2015). The timing of and gender biases in migration affect the labour pool availability for alternative crops. Further, gender shifts resulting from migration have implications for the delivery of agriculture extension services, including the accessibility of these services by generally less literate women (ADB 2015). For migration to be considered adaptive, implications on socio-demographics and subsequent ramifications need to be considered.
A lack of relationship between household food insecurity and purchasing food as a coping strategy, and between the diversity of strategies used by any one household and its status as a migrant or not migrant household, suggest households are using coping strategies that they either have access to or prefer. These choices likely depend on cash-flow status, access to money lenders, the ability to repay loans, or ownership of stock (for sale). Ad-hoc discussions with community members indicate that the use of famine foods (e.g. a traditional wild yam that grows on fallow land) is at least in part cultural, with some families avoiding these foods because of their association with the famine during the Khmer Rouge. That is to say, the choice of coping strategy may be psychological, associated with an individual’s or family’s previous experiences of trauma. Other studies (e.g. Craven and Gartaula 2015) identify cultured patterns of coping strategy, e.g. migrants were perceived as richer, a perception formed by food-purchasing behaviours, and an activity that resulted in livelihoods shifts away from agriculture—a lower social status activity. This simply shifted livelihood risks from climate, to geopolitical (i.e. seasonal migration schemes in New Zealand and Australia) rather than diversifying livelihood strategies to minimise risk sensitivity. Climate-induced shocks and stresses that accentuate food insecurity could therefore also unevenly affect community resilience, through changes in social status in addition to community wellbeing (e.g. negative impacts we reported on children and women’s security). Thus, if migration is to be adaptive, sensitivity to seasonal food insecurity and social status must also be addressed in a culturally sensitive way.
Implications for adaptation
Willams et al. (2016) argues that climate change adaptation has often missed the dual goal of adaptation and poverty reduction. From our analyses and discussion thus far, it is clear that (1) communities are at or below the economic threshold at which migration is ‘survival’ oriented; (2) the climate is becoming increasingly unpredictable, increasing exposure to economic risk; (3) climate is the most significant driver of migration; (4) the gendered and temporal nature of migration is causing socio-demographic shifts in remaining communities that impact on food insecurity; and (5) sensitivity to food insecurity is increased due to (a) gendered roles in agriculture, (b) the gendered nature of agriculture extension, and (c) cultural implications of adaptation activities that reduce exposure sensitivity. Climate change appears to be holding households in a cycle of food insecurity and migration. Addressing these issues requires consideration of adaptive capacity.
A simple response to food insecurity, long-term drying, and more variable rainfall (as evidenced in our NDVI analysis) is to promote irrigation to improve productivity (Wensveen and Roth 2016). Irrigation requires significant infrastructure development, usually incorporates a user pays element, requires co-operation between community for the opening and closing of canals, and requires electricity to operate pumps. This comes at a cost that is likely to be prohibitive for families without the ability to even feed themselves, or alternatively, it could be borne by further restricting women’s access to food or increasing debt.
A second solution is to improve climate resilience of crops to ensure productivity. However, this alone does not adequately address women’s role differences that may be limiting labour availability (see Sumner et al. 2017), or the fact that women are less literate, and have less access to extension services, markets, and technology (ADB 2015). Migration may also compound the intersections between gender and other factors (e.g. economic status) that affect livelihood outcomes and adaptation to climate change. As Carr and Thompson (2014) argue, a richer woman may have more in common with a richer man than she does with a poorer woman. Livelihood adaptation strategies require greater attention to the intersections of marginalisation, vulnerability and poverty if they are to succeed, given that attention to health, education, water, and credit access may have more impact on food insecurity than direct efforts to increase agricultural productivity (Bene and Friend 2011).
To ensure that migration is not maladaptive over the longer term, peak wet season food insecurity needs to be addressed. Migration clearly ought to be considered as part of livelihood development. Solutions are required for migrant households to develop alternative livelihoods that (1) are climatically sustainable, (2) address food shortages, (3) are less labour intensive or closer to home (to address welfare impacts of migration), and (4) can be utilised during periods of peak migration, such as secondary crops of mung-beans after rice yield, or vegetable crops. The costs of shifting livelihoods (such as skills, equipment, fertiliser, land, etc.) must be understood so as not to worsen household’s economic viability. Co-operative schemes, such as rice or chicken banks, are often seen as a mechanism for the introduction of new livelihood options. The long-term success of different co-operative models in Cambodia has not yet been explored. Co-operatives face further constraints in Cambodia because of their association with the Khmer Rouge. Improved understanding of cultural and gendered perspectives, including adaptation constraints and opportunities, are therefore critical to building effective long-term adaptation strategies that build resilience (Carr and Thompson 2014).