Sage Journals: Discover world-class research

Abstract

Despite the growth in the literature on the climate-conflict nexus since the 1990s, globalization of climate-exacerbated conflict through trade has received little attention until recently. This paper provides a meta-study on the share, trends and characteristics in the literature linking the variables of climate change, global trade and political instability/conflict. Through a systematic literature review, this study shows that (a) the literature on the climate-conflict-supply chains nexus is relatively scarce and scattered across disciplines, (b) there is a significant bias in favour of studying food supply chains, (c) there is an overwhelming focus on risk studies, with little attention on cooperation, management or adaptation, and (d) most studies do not focus on the instability/conflict effects of climate-related shocks, but on their economic consequences. An in-depth analysis of the 20 most cited papers of the sample confirms the biases found in the keywords and abstracts analysis, and shows that (a) links among the 3 topics are present in the literature, but in a scattered manner, and (b) there is a fertile ground for new research correlating climate-related shocks to instability/conflict, as well as for exploring the cooperation and adaptation measures of the world-trade regime to climate change.

Keywords

climate change supply chains conflict literature review resource scarcity natural resources

1. Introduction

Recent decades have shown that climate change is not only a problem that requires international cooperation to solve (Brennan, 2009; Nordhaus, 2015; Ylä-Anttila et al., 2018), but also that it oversteps into the boundaries of economic, societal and political spheres (Brzoska et al., 2020; Davies et al., 2020; Lazard & Youngs, 2021). Authors such as Scheffran (2020), Michel (2021), Ide et al. (2020), Mach et al. (2019) and Davies et al. (2020) identify feedback processes between conflict and climate change and explain the role of climate change as a ‘threat multiplier’. Extreme weather events, such as storms and floods can cause significant economic damage and disrupt supply chains for water, energy, food and other economic resources (Davies et al., 2020, p. 312; Sillmann, 2020), which in turn could feed resource-based conflict and social instability in fragile countries (Davies et al., 2020, pp. 313–315).

It is key to understand that there is still no definitive direct link between climate change and conflict (Pörtner et al., 2022), as results from empirical research on the nexus have not produced definitive answers, prompting the need to understand which variables mediate the effect (Ide et al., 2020; von Uexkull & Buhaug, 2021). Nevertheless, it is stated in some of the literature that, under context-specific preconditions, climate change events could significantly increase the probability, length and severity of conflict, particularly in ‘climate hotspots’ (Ide et al., 2020; Scheffran, 2020; Schleussner et al., 2016). Climate change events can increase grievances for accessing resources, diminish fiscal resources in the hands of the state to provide public services or maintain control, and reduce opportunity costs for contestation and violent conflict (Eklöw & Krampe, 2019; Food and Agriculture Organization [FAO], 2016, p. 12; Ide et al., 2020).

One mostly overlooked variable identified in the literature amplifying the problems caused by climate change is globalization (Scheffran, 2020, p. 21). Climate change not only stresses the resources of the most vulnerable countries, but also the functioning of supply networks and their receptors, multiplying the risk of economic losses, supply-side inflation, political instability and, in extreme cases, violent conflict (Davies et al., 2020; Wald et al., 2018). This means that global supply chains increase the sensitivity of coupling between variables (Centeno et al., 2015; Puma et al., 2015; Scheffran et al., 2012) and pose a major risk of creating ‘tipping points’ in the ways we handle key resources necessary for socioeconomic growth, environmental development and political stability, such as food, energy and strategic minerals (Brzoska et al., 2020; Kamenopoulos et al., 2015; Scheffran et al., 2012).

The relationship between climate change and supply chains, as well as the relationship between supply chains and increasing preconditions for conflict, has already been studied as individual pieces of a large puzzle in a variety of research areas. This research can be found in studies on climate-conflict nexus (Eklöw & Krampe, 2019; Ide et al., 2020; Schleussner et al., 2016), supply chain management (Chen & Wang, 2016; Davies et al., 2020; Kummu et al., 2020; Suweis et al., 2015), geoeconomics (Goldthau, 2021; Lazard, 2021; Michel, 2021), development policy (Muhammad et al., 2011; O’Trakoun, 2015; Qadri et al., 2020; Raddatz, 2005) and international relations (Keohane & Nye, 2012; Wald et al., 2018). Nevertheless, theoretical chains of connection are lacking, and scholars argue that more empirical studies on the globalization of climate vulnerability are necessary (Brzoska et al., 2020; Hendrix et al., 2023).

The goal of this study is to evaluate the current literature on the climate-conflict-supply chain nexus through a systematic literature review and understand the connections that have been established between each topic. This will set the state of the art in this topic, as well as the base on methods, theoretical links and empirical studies built on it.

The study will develop as follows: the first section will set the database, the literature search parameters for the study and the filtering parameters for the resulting literature. It will also determine the software tools for review for the key topic networks, graphs production and abstract analysis.

The second section will show the result of the systematic literature review search and show the size of the literature on the climate-conflict-supply chain nexus (relative to the size of the climate-conflict nexus literature), the main keywords of the studies and the major methodologies employed. In Section 3, the results from the systematic literature review are shown, and some inferences on the trends, biases and deficiencies of the current literature are made.

Section 4 will bring the 20 most cited papers from the search selected to understand the mainstream methods, main hypotheses and conclusions on the link between supply chains, climate change and conflict according to the literature.

Section 5 investigates the contribution (and limits) of the systematic literature review in building the long theoretical chain between climate-related supply chain disruptions and conflict, and determines main gaps in the literature for further research in the area. The final section will provide a first attempt of hypotheses on how climate change-related supply chain disruptions affect political stability and conflict, as well as possible means to test them.

2. Methodology: A systematic literature review with the analysis of key topics

Systematic literature reviews are a well-established method in the social sciences for understanding the state of the art of a field, whether a nascent one (Obinger & Petersen, 2017) or a well-developed one (Hunger & Paxton, 2022). It has also proven to be a good way to understand the geographic focus and methodological tendencies of said field (Scartozzi, 2021), and it is an established method in the climate-conflict nexus to assemble research from such a multidisciplinary field (Scartozzi, 2021; von Uexkull & Buhaug, 2021). Determining the search parameters for the systematic literature review is key for avoiding low sensitivity (coverage of all relevant studies) and low accuracy (minimizing the number of non-relevant studies in the search) (Petticrew & Roberts, 2006, pp. 81–85).

Because research on the relationship among climate change, conflict and globalization spans a variety of disciplines (environmental studies, economics, supply chain management, political science, geography, sociology, etc.), the initial search parameters are intended to provide maximum sensitivity, and accuracy is ensured through manual coding by the author.

The goal of the search is to understand (a) the increase in research findings on the nexus over time, (b) the proportion of these findings in the different disciplines, (c) the main keywords in the titles and abstracts of the literature, and (d) the methods used by the authors in their empirical studies. To achieve this, the study will use a combination of manual coding, Web of Science (WoS) results analysis and R packages specialized in literature review analysis. Table 1 shows the main objectives and the tools to achieve them.

Table 1.

Literature review objective, processes and tools.

Objective	Process	Tool
Collect all possible literature on the nexus among climate change, supply chains and conflict	Keywords-based literature search	Web of Science Database and search engine
Select relevant research articles on the empirical and theoretical links among climate change, supply chains and conflict	Abstracts and title analysis with selection conditions	Manual coding
Extract the major topics, disciplines and focus of the selected studies	Rake keywords and abstracts analysis with manual classification	R package litsearchr for rake analysis; manual coding for classification
Visualize topic, discipline and supply chain trends in the literature	Keywords count and visualization	R studio

The data consist of titles, abstracts, keywords and metadata of peer-reviewed journal articles from the WoS database ‘Clarivate’ (Web of Science). WoS is used not only for its accessibility and regular appearance in systematic literature reviews in political science (Hunger & Paxton, 2022), but also because it covers over 18,000 scientific journals and already has a search engine.

The search looks for research articles in the WoS core database with titles, abstracts, and keywords that contain at least one word for each of the three categories of research: Conflict, Climate Change, and Supply Chains (see Table 2). The broad inclusion of different types of conflict (including instability, war and even crime) is intended to increase the sensitivity of the search and provide a more thorough understanding of what theoretical and empirical connections are being made in the literature. Since there is not one form of conflict, including multiple forms of conflict is the optimal option. This study limits the search to 1990 as the earliest publication year. The reason for this is that the literature on the relationship between climate and conflict nexus started in the early 1990s with the studies on resource-based conflict by Homer-Dixon (1991, 1994) and his cluster (Scartozzi, 2021).

Table 2.

Keywords for Web of Science article search.

Nexus link	Keywords
Climate change	climat; disast
Supply chains	international trade; supply chain; globali
Conflict	instabil; protest; conflict; war; crim

Following the example of Kadir et al. (2019), once the initial dataset is created, the author will use paragraphs and title analysis to manually select research articles that are relevant to this study (Kadir et al., 2019, p. 5). To be relevant, the study must meet one of the following conditions: (a) it must show a theoretical or empirical correlation between climate change events and global trade impacts in any sector and/or between globalized trade disruptions and preconditions or manifestations of conflict such as political instability, crime and civil war; or (b) it must show a theoretical or empirical correlation between climate change-related policies and global trade impacts in any sector and/or between those impacts and preconditions or manifestations of conflict such as political instability, crime and civil war.

Once the pre-selection of research articles is completed, the study will extract key themes from the literature through Rake-based keyword extraction using R packages and classify these key concepts based on the supply chain analysed, the discipline of the study and the focus of the phenomenon studied. Based on the results, the study will provide a statistical analysis of the aforementioned themes over time in the selected literature. The objective is to understand (a) what are the main sectors that have been analysed in the literature so far, (b) what are the main focuses of the studies and (c) how the focus of the studies has shifted in the last 30 years of literature production.

Finally, following Hunger and Paxton (2022), the study will select the 20 most cited papers from the resulting set to identify (a) the most important concepts used in the literature and (b) the most commonly used theoretical chains behind the relationship among climate, trade and conflict. The goal of this section is to identify initial theoretical linkages for empirical studies as well as possible methods for future empirical studies.

3. Results: A new niche focused on food supply chains and risk

The naive search resulted in a premature set of 1,941 research articles due to the high sensitivity of the search parameters. Manual coding left 205 articles that fit the parameters of the study. A count across time shows that literature including supply chains started around 8 years later than general literature on climate-conflict nexus, and contributions in the literature started to climb after the systemic 2008 financial crisis (see Figure 1). After that event, the literature production in the area started to increase. The COVID and the Ukraine war crisis have catalysed knowledge production on this topic, as systemic vulnerabilities in the global trading system and climate shocks have driven academic production on the matter. Nevertheless, production in recent years accounts for only about 25 articles per year, indicating that the field is still nascent.

Figure 1.

Climate-conflict-supply chain nexus (1990–2023) Research articles published by year.

A look at the main categories shows that environmental sciences and studies are overrepresented in the literature, followed by economics (see Table 3). The conclusion of the analysis is that disciplines directly related to societal conflict, such as political science or international affairs, are quite low on the list. This is not surprising, as authors who have already dealt with the conflict-climate nexus (Brzoska et al., 2020; Hendrix et al., 2023) have talked about the lack of literature linking globalized interactions, climate change and various forms of conflict, both theoretically and empirically.

Table 3.

Categories of the articles on the climate-conflict-supply chain nexus (1990–2023).

Category	Count	Category	Count
Environmental studies	41	Business	8
Environmental sciences	38	Meteorology & atmospheric sciences	8
Economics	34	Geography	7
Food science & technology	19	Public, environmental & occupational health	7
Green & sustainable science & technology	17	Engineering, environmental	6
International relations	13	Operations research & management science	6
Agricultural economics & policy	12	Water resources	6
Energy & fuels	12	Development studies	5
Political science	10	Regional & urban planning	5
Management	9	Transportation	5
Other	75	Transportation	5

Source. Web of Science (2023).

There is also a significant bias in the literature with respect to the type of supply chains studied (see Figure 2). Food supply chains have always dominated the research articles since the beginning. Food supply chain risks have long been a major concern of development economists, climate scientists and supply chain managers. Events in recent decades have meant that water supply chains, which were on par with food supply chains in the early 2000s, have slowly become less important as energy supply chains have taken their place in the last 3 years.

Figure 2.

Climate-conflict-supply chain nexus (1990–2023) Research articles by supply chain type.

In recent years, mineral commodities and renewable energy supply chains have also emerged as a research topic, but contributions on this topic are still relatively small. As supply chain concentration and resource nationalism become more prevalent, it is likely that these two topics will become much more prominent in the near future.

An analysis of the research focus shows a clear bias in favour of studies on risk assessment, theorizing and correlation, especially after significant systemic shocks such as the 2008 financial crisis, the 2020 crisis COVID-19 and the 2022 Ukraine war (see Figure 3). Although there are some studies on adaptation, cooperation and management, studies with these foci are relatively rare in an already sparse literature.

Figure 3.

Climate-conflict-supply chain nexus (1990–2023) Research articles by focus type.

Finally, perhaps the most interesting finding is the large bias in favour of the economic consequences of the nexus between climate and supply chains, with relatively few studies focusing on the impacts on political instability, crime and conflict (see Figure 4). Although the number of articles addressing conflict as an independent or dependent variable has increased since 2020, contributions in this area have been small.

Figure 4.

Climate-conflict-supply chain nexus (1990–2023) Research articles by discipline.

Given the nature of the systematic literature review parameters, it is likely that this analysis ignores non-explicit links found in other studies on the climate-conflict nexus, such as the theoretical contributions by Scheffran (2020) and Brzoska et al. (2020) on how climatic events affect global trade and finance and multiply risk. Nevertheless, it still shows how rare the contributions are on this nexus in conflict research.

4. Discussion: Risk and increased complexity of fragile systems

The analysis of the 20 most cited articles shows the same biases as the statistical analysis of the previous section: (a) there is a significant bias in favour of studies that focus on the food supply chain; (b) most studies focus on risk, with only 4 studies addressing issues such as adaptation, cooperation and management; (c) the link between the aforementioned shocks and conflict variables is almost never directly addressed, with almost every study focusing on economic variables; and (d) most studies are from the field of economic and environmental studies (see Table 3). Interestingly, there is a fair distribution among literature review studies, empirical studies and modelling exercises, and some theoretical discussions of causal relationships.

Studies on climate change and food security have forecasted (and in some cases already demonstrated) the significant impacts of climate change on food production, distribution and consumption (Funk & Brown, 2009; Gregory et al., 2005; Puma et al., 2015; Tirado et al., 2010). Since 2005, risk assessment and production models have been developed for several food supply chains, including wheat and rice (Puma et al., 2015), maize (Tigchelaar et al., 2018) and potatoes (Haverkort & Verhagen, 2008). There is also ample evidence that these shocks and risks lead to preconditions of instability and conflict, such as poverty, diminished government capacity, food inflation and inequality, although conflict variables are not the main focus of most studies¹ (Funk & Brown, 2009; Gregory et al., 2005; Puma et al., 2015; Raddatz, 2005).

The introductory study of the components of food security by Gregory et al. (2005) shows that climate change is one of the main factors that affects food security. Climate change, combined with vulnerability variables such as poverty and inequality, make coping strategies unavailable or significantly more difficult, exacerbating the gravity and length of the food shock (p. 2,142). They argue that food security depends not only on productive capacity but on a combination of factors that include (a) society’s ability to cope with and recover from food shocks and (b) the country’s degree of exposure to those shocks (Gregory et al., 2005, p. 2,143). The study argues that food systems fail not only when production is inadequate, but also when related factors and/or linkages between them are disrupted by events such as climate change. In this regard, distribution infrastructure and capacity become critical. If infrastructure is overloaded due to lack of import or distribution capacity, and local food production chains are shaken by climate change, this can directly impact economic and physical access to food.

The systemic analysis of Puma et al. (2015) also shows that recent decades of food trade globalization have led to a significant increase in systemic vulnerability to so-called ‘key node shocks’, that is, shocks affecting increasingly concentrated staple food production centres.

An analysis of wheat and rice supply chains in 2005 to 2009 compared to 1992 to 1996 shows that (a) an increasing reliance on fewer global producers (this is particularly true for many Least Developed Countries, which by the 2005 to 2009 period depended on a single producer for over 90% of their wheat or rice supply); (b) a general increase in the share of production that is traded globally across countries; (c) a notable decline in self-sufficiency in some regions; and (d) increasing food trade restrictions in response to global supply shocks in exporting countries, which exacerbates the supply shock in import-dependent economies (Puma et al., 2015). This then compounds with the increased concentration of the food supply chain in relatively few buying desk and supermarket formats found by Gregory et al. (2005, p. 2,141).

A simulation of climate-induced supply shocks for these two supply chains shows that when gross domestic product (GDP) is considered as the main driver of redistribution – a phenomenon known as the ‘virtual water effect’ – the supply shocks are felt particularly strongly by low-income economies, which are allocated disproportionately less supply due to price increases (Puma et al., 2015, p. 10). This simulation does not take into account the impact of price subsidies on public spending and the outflow of hard currency that this shock has on these economies, which would exacerbate even more the economic burden they will bear during supply shocks (Gregory et al., 2005, p. 2,142).

In addition, Funk and Brown’s (2009) study shows that crop growth slowed between 1987 and 2007, and land use declined by 2% during this period (Funk & Brown, 2009). According to the FAO, per capita harvested area, fertilizer use and seed use declined by 20 to 30% during this period too in Funk and Brown (2009, p. 276). When competing uses of crops (biofuels, livestock feed, etc.) are factored in, by 2030 there is expected to be chronic food shortages, especially in low-income countries. Funk and Brown (2009) identified Asia and Africa as the most vulnerable regions due to a combination of low income and strong impacts of climate change on regional temperatures (p. 17).

These production, distribution and economic access problems are then compounded by globalization-related problems such as local food production collapse (Dell’Angelo et al., 2016), climate policy constraints on supply chains (Chen & Wang, 2016), increasing extreme shocks to supply chains (Sodhi & Tang, 2021), reduced storage capacity for economic efficiency (Mckinnon, 2009) and increasing vulnerability to production and trade access with few suppliers (Puma et al., 2015).

Raddatz’s (2005) study shows a significant correlation between external shocks such as commodity price fluctuations or climate disasters and economic variables relevant to conflict and instability, such as GDP per capita, government spending and the propensity to borrow (Raddatz, 2005).

A Vector autoregression (VAR) analysis over 30 years shows that negative external shocks have a direct negative effect on GDP per capita and government spending, and it reduces the propensity of governments to borrow (pp. 17–22). This effect is particularly radical – albeit of shorter duration – when trade-open, low-income and import/export-dependent economies are examined (pp. 23–26). Highly indebted economies are also particularly sensitive to these shocks, both in terms of severity and duration (pp. 23–26).

According to Centeno et al. (2015), this is all a byproduct of increasing reliance on complex systems to maintain living standards and economic growth. Dependence on highly efficient but fragile systems based on labour specialization, economies of scale, collective knowledge and information sharing carries precisely this risk and exposes us to catastrophic consequences arising from such relationships (Centeno et al., 2015, pp. 14.2–14.3).

Theory of Complex Adaptive Systems shows that these interactions and components cannot be reduced to its parts, which contributes to the system appearing stable even though fragility increases (pp. 14.3–14.4). However, the fragility arises from the same interaction of the system that brings it to an ‘edge of chaos’ where it is at risk of rupturing and vulnerable to what Centeno et al. (2015) refer to as ‘complexity catastrophe’, which bears a strong resemblance to the concept of ‘tipping points’ in environmental research.

The only studies directly related to conflict in the selected research articles were the study by Shams Esfandabadi et al. (2022) on the relationship between conflict and food/energy supply chains and Verhoeven’s (2011) critical-constructivist study on the Malthusian hypothesis of scarcity conflict.

Shams Esfandabadi et al. (2022) analyse the food supply chain in the midst of the Ukraine war and how it has led to a significant imbalance in wheat markets due to the importance of Ukraine and Russia in the chain (Shams Esfandabadi et al., 2022). This has created competition for wheat between food markets and biofuel producers, making first-generation biofuel production less profitable. Reduced biofuel production could hinder the energy transition and increase the appetite for petroleum, which would increase energy prices, which in turn would impact the fossil fuel supply chain.

Meanwhile, Verhoeven’s (2011) analysis questions the veracity of the hypothesis that resource scarcity increases the likelihood of resource-based conflict à la Malthusianism. Using Sudan as an example, he argues that environment, development and conflict are linked, but that a more nuanced analysis is needed to incorporate processes of inclusion, exclusion, resistance and discourse into studies of the climate-conflict nexus (Verhoeven, 2011, p. 701).

He argues that political and climate crises are instrumentalized through narratives by elite actors from the Global South to achieve their goals, and these narratives are then reinforced globally due to (a) the post-1989 U.S. securitization of the Global South, (b) the increasing desire to portray climate change as mainstream and a life-or-death situation, and (c) the tendency of policymakers and academics to focus on multicausality (p. 701). As a research agenda, he suggests shifting the focus from where Malthusian scenarios occur to why these scenarios are avoided in most cases.

5. Discussion: On the limits of systematic literature review and possible research options

In this paper, we conducted a comprehensive systematic literature meta-study on the characteristics and evolution of the link among climate change, supply chains and conflict. Starting with a naïve literature search of over 1,900 articles, the 200 results of eligible literature show that (a) the literature on the link among these 3 variables is sparse, but has shown significant growth since 2015; (b) that the literature has traditionally focused on food and water supply chains, with growing interest in critical minerals and the renewable energy supply chain; (c) that the literature mainly examines the direct link between climate change → supply shocks and → macroeconomic shocks, with little to no discussion of the implications of these shocks for political instability or conflict, or the systemic implications for the trading system; and that (d) an overwhelming majority of the literature focuses on risk, with few studies focusing on collaboration, adaptation or management.

Given the nature of this literature review, there are significant limitations. Studies on the links among climate change → global systems → stability/peace are still at a theoretical stage of development, with some significant contributions from climate-conflict experts such as Scheffran (2020), Brzoska et al. (2020), Ide (2023) or Hendrix et al. (2023) on the possible causal chains behind them. Nevertheless, this general approach to the topic in many ways escapes the parameters of a systematic literature review because the keywords are not present in all cases. Some studies that link systemic shocks (e.g. price shocks) to conflict but do not directly address climate change, like the research of Smith (2014) or McGuirk and Burke (2017), also escape the literature review, as one of the components of the keyword search is missing. Also, this article does not capture studies on topics that do not directly address globalized trade, but are heavily affected by it, like the studies of Eastin (2016), Koubi et al. (2014) and Lujala et al. (2005) on the nexus among disasters, abundance of tradable resources (oil, diamond, minerals, cash crops) and conflict. This limits the ability of a naïve search to cover all possible literature, especially the most theoretical and general discussions of this link, as well as discussion on related but not explicitly stated nexus.

Nonetheless, the study shows a clear niche of academic discussion where more literature is needed, with clear links scattered throughout the literature but few studies connecting them. It also clearly shows that there is a bias in terms of which supply chains are studied, what the focus of those studies is and which disciplines dominate the discussion.

The dearth of political science and international studies on this topic likely correlates with the scarcity of studies on the consequences of supply chain shocks in conflict/stability, particularly in export- and import-dependent economies. A thorough analysis of the 20 most cited papers in the study shows that links between export/import dependence and economic shocks have been found (Raddatz, 2005), and that the world has evolved in recent decades into a more globalized, interdependent and ‘fragile’ system (Centeno et al., 2015; Puma et al., 2015). These findings provide fertile ground for exploring the political implications of systemic fragility and globalized climate vulnerability.

Currently, the potential impact of local climate change-induced food shocks on conflicts related to the climate-conflict nexus is under intense scrutiny, with mixed results (Buhaug et al., 2015; Homer-Dixon, 2001; Hsiang & Burke, 2014; Ide et al., 2020). There are also few studies that attempt to understand the relationship between trade and political instability, from the positive effects for food producers to the impact of globalization and trade openness on instability (Awokuse & Gempesaw, 2005; Bussmann et al., 2006; Muhammad et al., 2011; Qadri et al., 2020). There is also discussion about the importance that global food shocks have had in major civil war events such as the Arab Spring (Soffiantini, 2020).

The variables that are often correlated to conflict and instability (lack of government revenue, increased poverty and inequality, inflation and unemployment) are found in the literature studied as consequences of climate-induced supply shocks, at least in the food supply chain. This provides an opportunity to examine whether this link can be extended to political variables such as protests, unrest, crime and even the duration and severity of civil wars.

It also provides an opportunity to examine the consequences of these shocks for diplomacy, cooperation and trade policy. The study by Puma et al. (2015) shows that trade policies in major food-exporting economies undergo significant changes when they face supply shocks to maintain food security, which then leads to a domino effect on the trade policies of self-sustaining food producers and exacerbates global price shocks. This relationship needs further research to understand how to avoid this policy domino effect.

Finally, there are ways to extend the climate-conflict nexus to supply chains beyond food and water. Poverty, government revenues and employment may also be affected in other types of supply chains, with equally important implications for political stability. Manufacturing supply chains can be disrupted at various stages of the process, affecting the rest of the chain, as studies by various authors have shown in recent years (Haraguchi & Lall, 2015; Levermann, 2014; Nakano, 2021).

Although manufacturing supply chains are more resilient to price shocks, they also affect the revenues and unemployment rates of several countries when they occur, which in turn can force customers to sever business relationships with the affected firms. The impact of unemployment on export-dependent communities has been studied (Ma et al., 2023), but more research is needed on how climate-related shocks and their erosive effects on trade can exacerbate unemployment and instability.

The topics of renewable energy, critical minerals and other energy- or defence-related supply chains open up the discussion of how climate change is creating a new geopolitical environment and supply chains. Theoretical studies already exist on how control over critical minerals and energy supply chains can exacerbate conflict in producer countries and promote interventionism by consumer countries (Di John, 2007; Kamenopoulos et al., 2015; Lazard & Youngs, 2021), but further empirical studies on the robustness of this correlation are still lacking.

Footnotes

Appendix 1

Table A1.

Top 20 cited papers in the literature review.

Research article	Link	Focus	Discipline	Methodology	Region	Relation to conflict
Brooks et al. (2005)	Climate disasters → Fatalities	Risk	Environmental studies	Empirical study/Correlation	Global	Direct
Gregory et al. (2005)	Climate Change → Food security	Risk	Biology	Literature review	NA	Indirect
Raddatz (2005)	Climate disasters → Economic growth	Risk	Economics	Empirical study/Correlation	Global	Indirect
Tirado et al. (2010)	Climate change → Food security	Risk	Food sciences	Literature review	NA	Indirect
Puma et al. (2015)	Climate change → Food security	Risk	Environmental studies	Network analysis and modelling	Global	Indirect
Dell’Angelo et al. (2016)	Globalization → Land grabbing	Risk	Development studies	Case studies	Global	Direct
Tigchelaar et al. (2018)	Climate change → Food security	Risk	Multidisciplinary sciences	Inferential statistics and modelling	Global	Indirect
Funk & Brown (2009)	Climate change → Food security	Risk	Food sciences	Empirical study/Correlation	Global	Indirect
Gozgor et al. (2020)	Globalization → Renewables	Adaptation	Economics	Empirical study/Correlation	Developed countries	Indirect
Bellon et al. (2011)	Climate change → Food security	Risk	Multidisciplinary sciences	Empirical study/Correlation	Latin America	Indirect
Chen & Wang (2016)	Climate policy → Supply chains	Risk	Economics	Network analysis and modelling	Central America	Indirect
Haverkort & Verhagen (2008)	Climate change → Food security	Risk	Agronomy	Literature review	NA	Indirect
Soddhi & Tang (2021)	Climate change → Supply chains	Risk; Management	Management	Literature review	NA	Direct
Centeno et al. (2015)	Globalization → systemic risk	Risk	Sociology	Theoretical discussion	NA	Direct
Rehman et al. (2021)	Globalization → Climate change	Risk	Energy & fuels	Empirical study/Correlation	South Asia	Indirect
Fidelman et al. (2011)	Climate change → International governance	Adaptation; Cooperation	International relations	Institutional analysis and development framework	Global	Direct
Shams Esfandebadi et al. (2022)	Conflict → Supply chains	Risk; Management	Energy & fuels	System thinking analysis	Global	Direct
Mckinnon (2009)	Globalization → systemic risk	Risk	Environmental studies	Network analysis and modelling	Organization for Economic Cooperation and Development	Indirect
Verhoeven (2011)	Climate change → Conflict	Risk	Development studies	Critical/Constructivist analysis	Sub-saharan Africa	Direct

Funding

The author disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was supported by the Deutsche Forschungsgemeinschaft (DFG) under Grant no. EXC 2037.

Ethical considerations

No ethical considerations were required on the realization of this paper, as it did not request the participation of third parties, the recollection of sensible data – such as human participants, human data and human tissue, or any kind of compromising field research. All the information gathered by this study was obtained through open data provided by Web of Science dataset of literature.

ORCID iD

Jesus Antonio Renzullo Narvaez

Data availability statement

All data provided was extracted from Web of Science under the parameters established in the publication.

Notes

Author biography

Jesus Antonio Renzullo Narvaez is a Doctoral Candidate on Political Science from Hamburg University (UHH) and Researcher at GIGA Hamburg. His research focuses on globalization of climate-conflict nexus. He holds a master in public policy from Erfurt University and a bachelor in international affairs from the Central University of Venezuela (UCV).

References

Awokuse

Gempesaw

2nd . (2005). Foreign political instability and U.S. agricultural exports: Evidence from panel data. Economic Bulletin, 6(11), 1–12. http://accessecon.com/pubs/EB/2005/Volume6/EB-05F10008A.pdf

Brennan

(2009). Climate change: A rational choice politics view. Australian Journal of Agricultural and Resource Economics, 53(3), 309–326. https://doi.org/10.1111/j.1467-8489.2009.00457.x

Brzoska

Scheffran

Alcón

Balbo

A. L.

Cruz

J. E. P.

Fröhlich

Abenza

R. G.

Avilés

J. M. G.

Hardt

J. N.

Heider

Hunink

Link

J. S. A.

Link

P. M.

Lopez

J. M. R.

Martinez-Fernández

Nash

S. L.

Neuburger

Puy

Rau

… Yang

L. E.

(2020). Climate change, security risks, and violent conflicts. Hamburg University Press. https://doi.org/10.15460/HUP.208

Buhaug

Benjaminsen

T. A.

Sjaastad

Theisen

O. M.

(2015). Climate variability, food production shocks, and violent conflict in Sub-Saharan Africa. Environmental Research Letters, 10(12), Article 125015. https://doi.org/10.1088/1748-9326/10/12/125015

Bussmann

Scheuthle

Schneider

(2006). Trade liberalization and political instability in developing countries. In Trappl

(Ed.), Programming for peace: Computer-aided methods for international conflict resolution and prevention (pp. 49–70). Springer Netherlands. https://doi.org/10.1007/1-4020-4390-2_3

Centeno

Nag

Patterson

Shaver

Windawi

(2015). The emergence of global systemic risk. Annual Review of Sociology, 41, Article 150504162558008. https://doi.org/10.1146/annurev-soc-073014-112317

Chen

Wang

(2016). Effects of carbon emission reduction policies on transportation mode selections with stochastic demand. Transportation Research Part E: Logistics and Transportation Review, 90, 196–205. https://doi.org/10.1016/j.tre.2015.11.008

Clarivate. Web of Science [Database]. Clarivate, London, United Kingdom.

Davies

Riddell

Scheffran

(2020). Preventing a warming war: Protection of the environment and reducing climate conflict risk as a challenge of international law. Goettingen Journal of International Law (Special Issue: Environmental Protection and Armed Conflicts), 10, 307–343. https://doi.org/10.3249/1868-1581-davies-riddell-scheffran

10.

Dell’Angelo

D’Odorico

Rulli

M. C.

Marchand

(2016). The tragedy of the grabbed commons: Coercion and dispossession in the global land rush. World Development, 92. https://doi.org/10.1016/j.worlddev.2016.11.005

11.

Di John

. (2007). Oil abundance and violent political conflict: A critical assessment. The Journal of Development Studies, 43(6), 961–986. https://doi.org/10.1080/00220380701466450

12.

Eastin

(2016). Fuel to the fire: Natural disasters and the duration of civil conflict. International Interactions, 42(2), 322–349. https://doi.org/10.1080/03050629.2016.1115402

13.

Eklöw

Krampe

(2019). Climate-related security risks and peacebuilding in Somalia. SIPRI. https://www.sipri.org/publications/2019/sipri-policy-papers/climate-related-security-risks-and-peacebuilding-somalia

14.

Food and Agriculture Organization (FAO). (2016). Peace, conflict and food security: What do we know about the linkages?

15.

Funk

Brown

(2009). Declining global per capita agricultural production and warming oceans threaten food security. Food Security, 1, 271–289. https://doi.org/10.1007/s12571-009-0026-y

16.

Goldthau

(2021). Widening the EU’s geoeconomic and regulatory approach to climate policy. In Lazard

Youngs

(Eds.), The EU and climate security: Toward ecological diplomacy (pp. 33–40). Carnegie Endowment for International Peace.

17.

Gregory

P. J.

Ingram

J. S. I.

Brklacich

(2005). Climate change and food security. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 360(1463), 2139–2148. https://doi.org/10.1098/rstb.2005.1745

18.

Haraguchi

Lall

(2015). Flood risks and impacts: A case study of Thailand’s floods in 2011 and research questions for supply chain decision making. International Journal of Disaster Risk Reduction, 14, 256–272. https://doi.org/10.1016/j.ijdrr.2014.09.005

19.

Haverkort

A. J.

Verhagen

(2008). Climate change and its repercussions for the potato supply chain. Potato Research, 51(3), 223–237. https://doi.org/10.1007/s11540-008-9107-0

20.

Hendrix

C. S.

Koubi

Selby

Siddiqi

von Uexkull

(2023). Climate change and conflict. Nature Reviews Earth & Environment, 4, 144–148. https://doi.org/10.1038/s43017-022-00382-w

21.

Homer-Dixon

T. F.

(1991). On the threshold: Environmental changes as causes of acute conflict. International Security, 16(2), 76–116.

22.

Homer-Dixon

T. F.

(1994). Environmental scarcities and violent conflict: Evidence from cases. International Security, 19(1), 5–40.

23.

Homer-Dixon

T. F.

(2001). Environment, scarcity, and violence. https://press.princeton.edu/books/paperback/9780691089799/environment-scarcity-and-violence

24.

Hsiang

S. M.

Burke

(2014). Climate, conflict, and social stability: What does the evidence say? Climatic Change, 123(1), 39–55. https://doi.org/10.1007/s10584-013-0868-3

25.

Hunger

Paxton

(2022). What’s in a buzzword? A systematic review of the state of populism research in political science. Political Science Research and Methods, 10(3), 617–633. https://doi.org/10.1017/psrm.2021.44

26.

Ide

(2023). Catastrophes, confrontations, and constraints: How disasters shape the dynamics of armed conflicts. The MIT Press. https://doi.org/10.7551/mitpress/14970.001.0001

27.

Ide

Brzoska

Donges

J. F.

Schleussner

C.-F.

(2020). Multi-method evidence for when and how climate-related disasters contribute to armed conflict risk. Global Environmental Change, 62, 102063. https://doi.org/10.1016/j.gloenvcha.2020.102063

28.

Kadir

Shenoda

Goldhagen

(2019). Effects of armed conflict on child health and development: A systematic review. PLoS One, 14(1), e0210071. https://doi.org/10.1371/journal.pone.0210071

29.

Kamenopoulos

Agioutantis

Komnitsas

Partsinevelos

(2015). A new tool for the geopolitical assessment of REE projects. Sustainable Development in the Minerals Industry 2015.

30.

Keohane

R. O.

Nye

J. S.

(2012). Power and interdependence (4th ed.). Longman.

31.

Koubi

Spilker

Böhmelt

Bernauer

(2014). Do natural resources matter for interstate and intrastate armed conflict? Journal of Peace Research, 51(2), 227–243.

32.

Kummu

Kinnunen

Lehikoinen

Porkka

Queiroz

Röös

Troell

Weil

(2020). Interplay of trade and food system resilience: Gains on supply diversity over time at the cost of trade independency. Global Food Security, 24, Article 100360. https://doi.org/10.1016/j.gfs.2020.100360

33.

Lazard

(2021). The need for an EU ecological diplomacy. In Lazard

Youngs

(Eds.), The EU and climate security: Toward ecological diplomacy (pp. 13–24). arnegie Endowment for International Peace.

34.

Lazard

Youngs

(2021). The EU and climate security: Toward ecological diplomacy (p. 80). Carnegie Europe.

35.

Levermann

(2014). Climate economics: Make supply chains climate-smart. Nature, 506, Article 7486. https://doi.org/10.1038/506027a

36.

Lujala

Gleditsch

N. P.

Gilmore

(2005). A diamond curse? Civil war and a lootable resource. Journal of Conflict Resolution, 49(4), 538–562. https://doi.org/10.1177/0022002705277548

37.

Pan

(2023, February 17). Work or Crook: The Socioeconomic Consequences of the Export Slowdown in China. https://ssrn.com/abstract=4232616 or http://dx.doi.org/10.2139/ssrn.4232616

38.

Mach

K. J.

Kraan

C. M.

Adger

W. N.

Buhaug

Burke

Fearon

J. D.

Field

C. B.

Hendrix

C. S.

Maystadt

J.-F.

O’Loughlin

Roessler

Scheffran

Schultz

K. A.

von Uexkull

(2019). Climate as a risk factor for armed conflict. Nature, 571(7764), Article 7764. https://doi.org/10.1038/s41586-019-1300-6

39.

McGuirk

Burke

(2017). The economic origins of conflict in Africa (Working paper no. 242; HiCN working papers). Households in Conflict Network. https://EconPapers.repec.org/RePEc:hic:wpaper:242

40.

Mckinnon

(2009). The present and future land requirements of logistical activities. Land Use Policy, 26, S293–S301. https://doi.org/10.1016/j.landusepol.2009.08.014

41.

Michel

(2021). Climate security, conflict prevention, and peacebuilding. In The EU and climate security: Toward ecological diplomacy. Carnegie Europe. https://www.researchgate.net/publication/353181623_Climate_Security_Conflict_Prevention_and_Peacebuilding

42.

Muhammad

D’Souza

Amponsah

(2011, October 1). Violence, political instability, and international trade: Evidence from Kenya’s cut flower sector (SSRN Scholarly Paper No. 1961207). https://ssrn.com/abstract=1961207 or http://dx.doi.org/10.2139/ssrn.1961207

43.

Nakano

(2021). Risk assessment for adaptation to climate change in the international supply chain. Journal of Cleaner Production, 319, Article 128785. https://doi.org/10.1016/j.jclepro.2021.128785

44.

Nordhaus

(2015). Climate clubs: Overcoming free-riding in international climate policy. American Economic Review, 105(4), 1339–1370. https://doi.org/10.1257/aer.15000001

45.

O’Trakoun

(2015). Food price uncertainty and political conflict. International Finance, 18(3), 299–320. https://doi.org/10.1111/infi.12073

46.

Obinger

Petersen

(2017). Mass warfare and the welfare state – Causal mechanisms and effects. British Journal of Political Science, 47(1), 203–227. https://doi.org/10.1017/S0007123415000162

47.

Petticrew

Roberts

(2006). How to find the studies: The literature search. In Petticrew

Roberts

(Eds.), Systematic reviews in the social sciences (pp. 79–124). John Wiley & Sons. https://doi.org/10.1002/9780470754887.ch4

48.

Pörtner

H.-O.

Roberts

D. C.

Tignor

M. M. B.

Poloczanska

E. S.

Mintenbeck

Alegría

Craig

Langsdorf

Löschke

Möller

Okem

Rama

(Eds.). (2022). Climate change 2022: Impacts, adaptation and vulnerability. Contribution of working group ii to the sixth assessment report of the intergovernmental panel on climate change. https://www.ipcc.ch/report/ar6/wg2/

49.

Puma

M. J.

Bose

Chon

S. Y.

Cook

B. I.

(2015). Assessing the evolving fragility of the global food system. Environmental Research Letters, 10(2), Article 024007. https://doi.org/10.1088/1748-9326/10/2/024007

50.

Qadri

Shah

Nadeem Qureshi

(2020). Impact of political instability on international investment and trade in Pakistan. European Online Journal of Natural and Social Sciences, 9, Article 2.

51.

Raddatz

(2005). Are external shocks responsible for the instability of output in low income countries? (Policy research working paper series, 3680). The World Bank. https://ideas.repec.org//p/wbk/wbrwps/3680.html

52.

Scartozzi

C. M.

(2021). Reframing climate-induced socio-environmental conflicts: A systematic review. International Studies Review, 23, 696–725. https://doi.org/10.1093/isr/viaa064

53.

Scheffran

(2020). Climate change and weather extremes as risk multipliers: Tipping points, cascading events, and societal instability.In Brzoska

Scheffran

(Eds.), Climate change, security risks, and violent conflicts (pp. 19–48). Hamburg University Press.

54.

Scheffran

Link

P. M.

Schilling

(2012). Theories and models of climate-security interaction: Framework and application to a climate hot spot in North Africa. In Scheffran

Brzoska

Brauch

H. G.

Link

P. M.

Schilling

(Eds.), Climate change, human security and violent conflict: Challenges for societal stability (pp. 91–131). Springer. https://doi.org/10.1007/978-3-642-28626-1_5

55.

Schleussner

C.-F.

Donges

J. F.

Donner

R. V.

Schellnhuber

H. J.

(2016). Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries. Proceedings of the National Academy of Sciences, 113(33), 9216–9221. https://doi.org/10.1073/pnas.1601611113

56.

Shams Esfandabadi

Ranjbari

Scagnelli

. (2022). The imbalance of food and biofuel markets amid Ukraine-Russia crisis: A systems thinking perspective. Biofuel Research Journal, 9, 1640–1647. https://doi.org/10.18331/BRJ2022.9.2.5

57.

Smith

T. G.

(2014). Feeding unrest: Disentangling the causal relationship between food price shocks and sociopolitical conflict in urban Africa. Journal of Peace Research, 51(6), 679–695. https://doi.org/10.1177/0022343314543722

58.

Sodhi

M. S.

Tang

C. S.

(2021). Supply chain management for extreme conditions: Research opportunities (SSRN Scholarly Paper No. 3861194). https://doi.org/10.2139/ssrn.3861194

59.

Soffiantini

(2020). Food insecurity and political instability during the Arab Spring. Global Food Security, 26, 100400. https://doi.org/10.1016/j.gfs.2020.100400

60.

Suweis

Carr

J. A.

Maritan

Rinaldo

D’Odorico

(2015). Resilience and reactivity of global food security. Proceedings of the National Academy of Sciences, 112(22), 6902–6907. https://doi.org/10.1073/pnas.1507366112

61.

Tigchelaar

Battisti

D. S.

Naylor

R. L.

Ray

D. K.

(2018). Future warming increases probability of globally synchronized maize production shocks. Proceedings of the National Academy of Sciences, 115(26), 6644–6649. https://doi.org/10.1073/pnas.1718031115

62.

Tirado

M. C.

Clarke

Jaykus

L. A.

McQuatters-Gollop

Frank

J. M.

(2010). Climate change and food safety: A review. Food Research International, 43(7), 1745–1765. https://doi.org/10.1016/j.foodres.2010.07.003

63.

Verhoeven

(2011). Climate change, conflict and development in Sudan: Global neo-Malthusian narratives and local power struggles. Development and Change, 42(3), 679–707. https://doi.org/10.1111/j.1467-7660.2011.01707.x

64.

von Uexkull

Buhaug

. (2021). Security implications of climate change: A decade of scientific progress. Journal of Peace Research, 58(1), 3–17. https://doi.org/10.1177/0022343320984210

65.

Wald

Rosin

Dawson

(2018). Global resource scarcity: Catalyst for conflict or cooperation? (Edited volume). Routledge.

66.

Ylä-Anttila

Gronow

Stoddart

M. C. J.

Broadbent

Schneider

Tindall

D. B.

(2018). Climate change policy networks: Why and how to compare them across countries. Energy Research & Social Science, 45, 258–265. https://doi.org/10.1016/j.erss.2018.06.020

The nexus among climate change,conflict and supply chains: A systematic literature review from 1990 to 2023

Abstract

Keywords

1. Introduction

2. Methodology: A systematic literature review with the analysis of key topics

3. Results: A new niche focused on food supply chains and risk

4. Discussion: Risk and increased complexity of fragile systems

5. Discussion: On the limits of systematic literature review and possible research options

Footnotes

Appendix 1

Funding

Ethical considerations

ORCID iD

Data availability statement

Notes

Author biography

References