On sustainability, vulnerability,
climate and conflict
Colin Kelley
Dr Kelley is a climate scientist
focusing on climate variability and change, particularly drought, in semiarid
and arid regions that are especially vulnerable. He is an Associate Research
Scientist with Columbia University’s International Research Institute for
Climate and Society and a Senior Research Fellow with the Center
for Climate and Security in Washington, DC.
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DOI: 10.3197/jps.2016.1.1.35
Licensing: This article is Open Access (CC BY 4.0).
How to Cite:
Kelley, C. 2016. 'On sustainability, vulnerability, climate and conflict'. The Journal of Population and Sustainability 1(1): 35–44.
https://doi.org/10.3197/jps.2016.1.1.35
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Introduction: vulnerability and
resilience
The human population of the Earth is
over 7.4 billion and growing.[1]Population growth inherently increases
demand for resources, such as humans’ most basic needs, water and food. In 1798
Thomas Robert Malthus (1798) introduced the theory that, if left unchecked, the
population of our planet will, at some point, outgrow its resources, exceeding
the planet’s carrying capacity. Malthus’s theory did not foresee technological
advances in food production (Green Revolution) [2] and it is similarly difficult for us
to envision what the future holds with respect to the relationship between
resource supply and demand. It is fair to say, however, that the Earth is on an
unsustainable trajectory. Now, over 200 years after Malthus introduced the
theory, the world’s population growth is still outpacing the growth in food
production.
One characterization of a nation’s
sustainability lies in the balance between the supply and demand of its
resources. Changes in demand, due to population growth for example, or supply,
such as declining access to food and water, act to increase the strain on
existing vulnerability. Every region and nation comprises a unique combination
of population, geography, governance, economy, access to natural resources,
social and religious structure/diversity, climate and other characteristics.
The interdependence between these many factors is distinctive and often quite
complex, on both spatial and temporal scales. Each nation varies with respect
to its inherent vulnerability, or alternately its fundamental lack of
resilience to change, and therefore in its capacity to adapt.
Many nations/regions are
disproportionately vulnerable to changes, particularly abrupt changes (or
‘shocks’), due to inherently limited access to water or other resources, for
instance. Semi-arid and arid regions certainly fall in this category. When such
changes occur, these nations are more likely to exceed their thresholds of
resilience, sometimes leading to conflict, ranging from small-scale land and
water disputes to full-scale war. This is not to suggest a climate determinism
however, as there are also examples where extreme climatic changes have
resulted in increased cooperation rather than violence (Subramanian et al.,
2015). When large-scale conflicts do occur they further compound existing
difficulties, sometimes leading to forced migration internally and perhaps even
spilling over national boundaries when people seek refuge elsewhere, further
increasing the strain on resources in those host countries, and so on.
A society’s climate has a central influence
on its ability to succeed and flourish or conversely to suffer and fail.
Climate change is thought by many to be the greatest challenge facing our
planet and its inhabitants (not only humans) now and for the remainder of this
century (and perhaps much longer). When the climate changes, particularly in
abrupt or extreme ways, it can directly impact access to water and food. Water
is of course vital for human consumption and for cultivation of agriculture and
livestock. Hence a society’s vulnerability is, and has always been, directly
linked to changes in climate.
Climate and civilisation in history
Links between the rise and decline of
ancient civilizations and changes in their climatic conditions have long been
theorized. Such changes are directly associated with access to water and, by
extension, agricultural potential. The collapse of the highly developed
Akkadian Empire that ruled in Mesopotamia roughly four millennia ago was
attributed to a sudden shift to more arid conditions. Similar collapses occurred
in Egypt and in India during the same period (Cullen, 2000).
The Mayan civilization flourished
during a period of wetter than normal conditions over two centuries and then
collapsed after an ensuing period of declining rainfall that lasted three centuries.
This climate change triggered a fragmentation of society and governance and an
increase in warfare, and was followed by an extended drought and a population
collapse (Kennett et al., 2012).
The demise of Angkor in the Khmer
empire in Cambodia has been attributed to the combination of drought and
intense monsoonal rainfall that impacted the city’s water supply and
agricultural productivity and damaged its water control infrastructure (Buckley
et al., 2010).
The Roman Empire rose during a period
of stable and favorable climatic conditions, and then
fell into crisis during the Empire’s third century under deteriorating climatic
conditions. The Empire recovered in a second, briefer period of favorable conditions, after which regional differences in
climate conditions coincided with the diverging fates of the eastern and
western Empires in subsequent centuries. Additionally, climate conditions
beyond the Empire’s boundaries played an important role by affecting food
production in the Nile River valley, and by encouraging two major migrations
and invasions of pastoral peoples from Central Asia (McCormick et al., 2012).
These are merely examples and are not
listed here to imply that climate is the single determining factor in a
civilization’s relative success or lack thereof. As mentioned above, the
relationship between the many important factors is quite complex; but it is
reasonable to conclude that climatic factors have often played an important
role. This applies to modern times as well.
Climate change and violence today
There have been a number of studies
linking climate to violence in the modern era, (Cane et al., 2014; Hsiang and
Burke, 2014) but other studies downplay the importance of such links. Although
this body of literature has at times been contentious (Hsiang and Meng, 2014),
climate can play a role, whether small or large, in a society’s ability to
flourish or even succeed. Abrupt changes in climate can often push a society’s
resilience beyond its ability to effectively adapt.
This leads to the example of Syria.
The Fertile Crescent, where agriculture and herding began over ten thousand
years ago, receives most of its yearly rainfall during the winter months, from
late October to early April. A study conducted by myself and others and
published in the Proceedings of the National Academy of Sciences (PNAS) in
early 2015 (Kelley et al., 2015), found that from 2006-2010 the region
experienced its worst multi-year winter drought in the observed record.
Figure 1. Rainfall (1901–2008): Precipitation
patterns are changing in the Fertile Crescent. Rainfall from November through
April, when most of it occurs, has decreased 13% since 1931. The gray boxes represent multi-year droughts, which are defined
as three or more consecutive years when precipitation is below the century-long
average.
Graphic based upon LaFond (2016)
This unusually severe drought
directly preceded Syria’s Arab Spring uprising (in early 2011). The severity
and duration of the drought caused an agricultural collapse and a subsequent
mass migration of farmers and their families to the urban areas in Syria’s
west. The influx of internally displaced people into the cities after the prior
arrival of Iraqi refugees and on top of robust natural population growth, led
to overcrowding, a lack of employment and resources, a sharp increase in crime
in the urban peripheries and, perhaps most importantly, little or no relief
from the government. The Syria conflict escalated into a prolonged and bloody
civil war that led to Syrians fleeing the country for their safety and causing
a global refugee crisis.
Governance is perhaps chief among the
factors that led to Syria’s instability. The Syrian government had for decades
encouraged wheat and even water-intensive cotton production, and Syria had
succeeded in becoming a net exporter of wheat, to the point that it reached 25%
of their total GDP. When the drought occurred Syria abruptly went from a net
exporter to a net importer of wheat, which put them at the mercy of global food
prices, high at the time. Another example of poor governance is the clear
failure by the Assad regime to address the suffering of the displaced rural
population.
Syria’s agricultural stability over
these decades, among other factors, had led many to believe that it was less
susceptible to the unrest that was taking place in the other Arab Spring
nations. This was clearly not the case however. In 2012, shortly after the war
in Syria began, the Center for Climate and Security
highlighted the possible connections between climate change, drought, natural
resource mismanagement and instability in Syria, drawing on previous research
on Mediterranean drying (Hoerling et al., 2012) and
on a 2010 drought vulnerability report from the United Nations Office for
Disaster Risk Reduction (UNISDR). The subsequent PNAS study in 2015 validated
the assessment of the role of climate change in the drought, showing that the
emerging climate change signal in the Fertile Crescent made that severe drought
two to three times more likely.
Figure 2. Separating the influence of
climate change (1932–2007): Using measurements of carbon dioxide concentrations
in the atmosphere coupled with climate models and statistical analysis,
scientists were able to estimate what rainfall in the Fertile Crescent would
have looked like without the influence of climate change.
Graphic based upon LaFond (2016)
The Syrian government’s strong
dependence on agriculture, which was initially implemented in the interest of
national security, ironically depended not only on the rain that typically
falls in Syria, but also the water that flows in through the Tigris and
Euphrates rivers, and perhaps most importantly on groundwater. Groundwater, in
semi-arid and arid regions in particular, has long been a vital complement to
rainfall for irrigation purposes. Exponential population growth was responsible
for a dramatic increase in the extraction of groundwater. In 1950, Syria’s
population was roughly 5 million and has since grown to nearly 25 million. This
increased stress alone put Syria in an untenable position. Declining
groundwater in the Fertile Crescent is merely an example of a systemic problem
globally, one that is a very real threat to sustainability even before the
deleterious effects of climate change are considered.
A newly released study, using
tree-ring data from throughout the greater Mediterranean, characterized the
natural rainfall variability over the last 900 years (Cook et al., 2016). Much
of the region’s weather is linked to atmospheric variability over the North
Atlantic. This natural variability ranges from very short to much longer time
scales. The latter manifests itself in consecutive decades of drier or wetter
than normal conditions over Europe. The greater Mediterranean region has
experienced a significant decrease in winter rainfall over recent decades, and
at least part of the drying is due to climate change (Kelley et al. 2011). In
the eastern Mediterranean, Fertile Crescent/Levant region, the longer-term
natural variability over the North Atlantic holds less sway and the climate
change signal is therefore more distinct (Kelley et al., 2011). Thus the recent
increase in the frequency and the severity of multi-year droughts in this
region over recent decades is believed to be due to human-induced climate
change. Droughts such as the most severe one that occurred just prior to
Syria’s collapse were estimated to be two to three times more likely due to the
climate change influence (Kelley et al., 2015). The new tree ring study
provides compelling convergent evidence that the recent drying in the
Levant/Fertile Crescent is well outside the range of natural variability over
the last 900 years and is therefore very likely to be human-induced.
Yemen, another Arab Spring nation, is
one of the poorest and most food insecure nations in the world and has been for
some time. Yemen and Syria are similar in a number of ways. They have faced
nearly identical population increases since 1950, both are highly agrarian
societies and both depend strongly on groundwater, which has declined rapidly.
Again, these are factors associated with high vulnerability before the effects
of climate change are even considered. Most of Yemen’s population resides in
its west, near the mountains that run parallel to the Red Sea coast. Although
this region does not receive an abundance of rainfall it is easily the wettest
in all of the Arabian Peninsula. As such, western Yemen has the capacity for
fairly diverse agriculture; but Qat, the mild narcotic that has been grown for
many generations, has begun to supplant food crops due to its more regular
yield and high profitability. Clearly, for a nation that is poor and food
insecure, the decline in food crops is alarming. Worse, however, is that Qat is
highly water dependent, much more so than food crops, and is increasing the
strain on Yemen’s rapidly declining groundwater.
It has been suggested by some that
Yemen’s capital city of Sanaa may be the world’s first to run out of water.
Unlike Syria, Yemen has not seen a significant decline in rainfall over the
last 40 years, although both nations, like much of the greater Middle East,
have experienced a strong increase in surface temperature.
Figure 3. Temperature (1901–2009):
Temperature has shown a long-term increasing trend in the Fertile Crescent.
Every year from 1994 through 2009 was warmer than the century-long average for
the region.
Graphic based upon LaFond (2016)
This is important because higher
temperatures, among other factors, cause more water to evaporate from the soil.
The enhanced drying of the soil during the dry months has a cumulative effect,
inhibiting groundwater recharge. Although Yemen did not experience a climate
‘shock’ similar to the extreme drought in Syria, in early 2015 it too collapsed
into large-scale conflict.
As with Syria, it is important to
reiterate that Yemen’s conflict owes its existence to many important factors,
not only to conditions made worse by climate change. Again, each nation is
distinct in not only its response to climate change, but in the relationship
between the many factors that combine to produce vulnerability. There are
numerous other examples of nations experiencing climate change in one form or
another and how it has added to their existing vulnerabilities and heightened
the overall water and resource stress, with differing outcomes. To accurately
assess each country’s (or region’s) threshold of resilience, with an eye toward
building the capacity to predict when that threshold may be crossed, is a
tremendous challenge.
As of this writing, tentative ceasefires
have been agreed upon for Syria and Yemen. The future of these two nations is
far from clear. What is clear, however, is that Syria’s civil war has had a
profound effect on the rest of the world. Thus, it stands as a primary example
of how climate change can combine with other key factors to exacerbate existing
food and water security and social challenges and to push a vulnerable region
beyond its resilience. As such, the security communities, including Department
of Defense (2014), have taken climate change very
seriously for some time now.
The examples of Syria and Yemen
perhaps beg the question of who will be next? Prior to its uprising, Syria was
widely viewed by experts as stable and largely immune to the effects of the
Arab Spring. According to a recent study (Werrell et
al., 2015) certain popular indices of nation-state fragility (Fund for Peace’s
Fragile State Index, for instance) corroborated this belief; in hindsight it
was not in fact the case. This leads to the conclusion that, while prediction
of state failure or conflict is clearly a highly complex task involving
numerous variables, there is strong reason to believe that closer examination
of regional climate change and resource availability change could greatly
improve existing state fragility indices, providing policy makers with better
information with which to make informed decisions.
[1] http://www.worldometers.info/world-population/
[2] See Evenson
and Gollin (2003)
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