Climate variability, crop and conflict: Exploring the impacts of spatial concentration in agricultural production
| Published date | 01 January 2021 |
| Date | 01 January 2021 |
| DOI | http://doi.org/10.1177/0022343320971020 |
| Subject Matter | Regular Articles |
Climate variability, crop and conflict:
Exploring the impacts of spatial
concentration in agricultural production
Paola Vesco
Department of Peace and Conflict Research,
Uppsala University & CMCC, Euro-
Mediterranean Center on Climate Change
Matija Kovacic
Department of Economics, Ca’ Foscari
University of Venice & European Commission,
Joint Research Centre (JRC), Ispra
Malcolm Mistry
Department of Economics, Ca’ Foscari University
of Venice & CMCC, Euro-Mediterranean Center
on Climate Change
Mihai Croicu
Department of Peace and Conflict Research,
Uppsala University
Abstract
Although substantive agreement exists on the role of climate variability and food scarcity in increasing violence, a
limited number of studies have investigated how food resources affect violent conflict. This article explores the
complex linkages between climate variability, agricultural production and conflict onset, by focusing on the spatial
distribution of crop production in a cross-country setting. We hypothesize that spatial differences in crop production
within countries are a relevant factor in shaping the impact of climate variability on conflict in agriculturally -
dependent countries. To test this hypothesis, we rely on high-resolution global gridded data on the local yield of four
main crops for the period 1982–2015 and aggregate the grid-cell information on crop production to compute an
empirical indicator of the spatial concentration of agricultural production within countries. Our results show that the
negative impacts of climate variability lead to an increase in the spatial concentration of agricultural production
within countries. In turn, the combined effect of climate extremes and crop production concentration increases the
predicted probability of conflict onset by up to 14% in agriculturally dependent countries.
Keywords
agriculture, food, climate variability, conflict
Introduction
Substantial agreement exists that climatic conditions can
impact security through intermediate pathways and/or
under some specific conditions (Mach et al., 2019). Yet,
the mechanisms connecting climate to conflict and the
conditions that make this link more likely to arise are rather
unclear (Koubi, 2019). Among the examined channels
through which climate variability can influence conflict,
agriculture and food security have received great attention
(Wischnath & Buhaug, 2014; Koren et al., 2021). This is
not surprising as conflict is arguably most widespread in
developing countries, which are not only heavily depen-
dent on agriculture (Lotze-Campen & Schellnhuber,
2009), but also disproportionately affected by changes in
climatic conditions (Porter et al., 2014). However,studies
of the climate–conflict nexus still lack explicit incorpora-
tion of agricultural variables inthe models, which is essen-
tial to improve the specifications of their theoretical
argumentations (Meierding, 2013).
Corresponding author:
paola.vesco@pcr.uu.se
Journal of Peace Research
2021, Vol. 58(1) 98–113
ªThe Author(s) 2021
Article reuse guidelines:
sagepub.com/journals-permissions
DOI: 10.1177/0022343320971020
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The main argument of this study follows three steps,
leading from climate extremes to conflict. First, the nega-
tive impacts of climate variability increase the spatial con-
centrationof crop production across locations. Second,the
spatial distribution of crop production, which measures
how food access and livelihood conditions vary across
locations, is a relevant factor to shape the impact of
climate on conflict in agriculturally dependent coun-
tries. Third, the combined effect of climate extremes and
spatial concentration of crop production increases the
likelihood of conflict onset.
We test this argument by constructing a time-variant
Gini Index of crop production (GICP henceforth) within
countries. GICP provides a measure of the spatial distri-
bution of crops, that is, how concentrated or dispersed
crop production is across locations. Higher values of
GICP correspond to food output being concentrated in
few areas of the country, while lower levels of GICP indi-
cate that crop production is more homogeneously distrib-
uted. GICP enables us to examine how the spatial
distribution of agricultural resources shapes the effect of
climate on conflict over time. A set of validation tests
proves that GICP is a good measure of populations’ liveli-
hood and access to food.
To this end, the present analysis contributes to the
previous literature to several extents. First, the study
introduces a novel, time-varying measure of spatial
dispersion/concentration of crop production at the
country level. The use of GICP enables us to explicitly
examine the effect of climate extremes on the spatial
distribution of crop production within countries and
over time. Growing scientific evidence suggests that
the impact of climate variability on agricultural pro-
duction will vary considerably across space (Lobell,
Schlenker & Costa-Roberts, 2011), yet this relation-
ship has seldom been tested empirically. Second, our
analysis complements both country-level studies and
disaggregated analyses of the climate–conflict nexus,
by capturing a spatial dimension of vulnerability
related to crop production. Specifically, this article
thoroughly investigates the effect that geographical
patterns of crop production may exert on conflict;
these patterns have been generally overlooked by other
investigations, although implicitly assumed to occur.
Finally, our study makes use of new time-varying data
of agricultural production at the grid-cell level, along
with a wide set of climatic indicators which are expli-
citly relevant to agricultural production.
The rest of the article proceeds as follows: the first
section elaborates our argument on climate variability,
crop production and conflict; the second section presents
the data and illustrates the construction and validation of
GICP; the final part discusses our empirical models and
presents the results.
Climate variability, crop production
concentration and conflict
The impacts of climate variability
1
on agricultural pro-
duction are well established in the scientific literature.
Natural extremes and anomalies in weather conditions
that result from climate variability are already reducing
crop productions at the global level, a trend that is pro-
jected to continue as temperatures rise further (Lobell,
Schlenker & Costa-Roberts, 2011). If no adaptation
takes place, global yields are expected to decrease at a
pace of 1.5% per decade (Lobell & Gourdji, 2012) and
losses in aggregate production will affect wheat, rice and
maize in both temperate and tropical regions by 2Cof
local warming (Challinor et al., 2014). Crop-level adap-
tation and technological innovation can moderate losses
to some extent (Rosenzweig & Parry, 1994) but adaptive
capacity is projected to be exceeded in regions closest to
the equator if temperatures increase by 3Cormore
(Porter et al., 2014).
However, when one moves from a global to a local
(e.g. national or regional) focus, the impacts of climate
variability become more complex. While climate anoma-
lies are expected to have spatially heterogeneous impacts
on agriculture, yielding a net negative effect at the global
level (Lobell, Schlenker & Costa-Roberts, 2011), their
impacts at a local scale are less straightforward, and they
are expected to vary across both time and space (Kang,
Khan & Ma, 2009).
Not only the impacts of climate on food production
may vary across space (Iglesias et al., 2009, 2012), but
countries’ adaptive capacity to weather shocks is unlikely
to be spatially homogeneous and rather differs across
locations and strata of the populations within the same
country (Alam, 2017). One key aspect that can restrain a
country’s resilience to climate variability is represented
by the spatial distribution of food; the negative impacts
of climate variability are likely to increase relative
1
Climate change involves persistent shifts in the mean and variation
of surface weather conditions, such as temperature, precipitation and
wind, observed at a multidecadal scale or longer (WMO, 2017).
Climate variability refe rs to short-term or interannu al changes in
surface weather conditions, which can lead to anomalies in climatic
statistics and the occurrence of extremes beyond those of individual
weather events. Although climate variability denotes a different
concept than climate change, it is an effect of long-term variations
in climate.
Vesco et al. 99
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