Climate bones of contention: How climate variability influences territorial, maritime, and river interstate conflicts

Abstract

Many scholars examine the relationship between climate variability and intrastate conflict onset. While empirical findings in this literature are mixed, we know less about how climate changes increase the risks for conflicts between countries. This article studies climate variability using the issue approach to world politics. We examine whether climate variability influences the onset and militarization of interstate diplomatic conflicts and whether these effects are similar across issues that involve sovereignty claims for land (territory) or water (maritime, river). We focus on two theoretical mechanisms: scarcity ( abundance) and uncertainty. We measure these concepts empirically through climate deviation (e.g. droughts/floods, heat waves/cold spells) and climate volatility (greater short-term variance in precipitation/temperature). Analyses of issue claims in the Western Hemisphere and Europe (1901–2001) show that greater deviations and volatility in climate conditions increase risks for new diplomatic conflicts and militarization of ongoing issues and that climate change acts as a trigger for revisionist states.

Security implications of climate change: A decade of scientific progress

“…Contrary to expectations, they find that drought exposure correlates with increased intergroup trust, suggesting that if a general conflict-inducing effect of drought exists, it must work through other mechanisms than ethnic polarization. Finally, Schmidt et al (2021) shed new light on the understudied interstate dimension of climate security. They show that anomalous climate conditions can shape the risks for new diplomatic conflicts and militarization of ongoing issues, and that chances for issue claims and conflict initiation are greatest for revisionist states.…”

A Song of Neither Ice nor Fire: Temperature Extremes had No Impact on Violent Conflict Among European Societies During the 2nd Millennium CE

“…For at least 60 years, social scientists have tried to understand that process by identifying the correlates of warfare, motivated largely by a desire to predict and ideally prevent the process from giving rise to violence in the future (Suzuki et al, 1998). Recently, climate change has taken a central position in the literature on this topic, with many scholars declaring that climatic changes can be expected to increase the risk of violent conflict (e.g., Burke et al, 2009Burke et al, , 2015Hsiang et al, 2013;Schmidt et al, 2021).…”

“…Essentially, the likelihood that any given pair-or "dyad"-would have actually engaged in violent conflict cannot be controlled for. A dyad approach has, for this reason, become common in research on modern international conflict and politics (Croco and Teo, 2005;Gleditsch et al, 2014;Schmidt et al, 2021). In a dyad study, the unit of analysis is conflict in a given time interval between specified pairs of potential combatants.…”

“…This dynamic creates a feedback that could be hard to detect empirically even at an annual resolution and may require more complex statistical models. Along similar lines, it may be necessary to take into account additional mediating variables-e.g., population size, carrying capacity, political history-before the impact of climate change on conflict levels can be detected (Schmidt et al, 2021). Climate change including extreme events like the Little Ice Age may only impact conflict levels when a society is near its effective carrying capacity, which is a function of technology, population size, and the ability of socioeconomic institutions to buffer shortages (Alfani, 2010;Alfani and Ó Gráda, 2018).…”

“…Reluctance to hand over resources would then give rise to organised violent conflicts. Scholars of international relations and conflict and peace researchers have referred to this putative causal chain as a "scarcity mechanism' and it has intuitive appeal (e.g., Glowacki and Wrangham, 2013;Koubi, 2019;Schmidt et al, 2021). Even in cases where compensatory strategies were available (e.g., alternate foods, trade), these would not always work as hoped-trade agreements fail and alternate resources are not always sufficient.…”