I have obscured the names of a couple of people mentioned in the original dialogue.
critical reviewer: "The second issue is that the two papers (Gleick and Kelley et al) do not make the claim in the aforementioned sentence (which was "It is true that a growing number of commentators from the UK’s Prince Charles onwards, are making a claim, but none of these is based on any analysis of the Syrian conflict, but repeating a now received wisdom" - ie the reviewer claims that neither Gleick nor Kelley et al argue that the drought is linked to conflict). Kelley et al is a straightforward climatological account of drought in the region with a climate science ‘detection and attribution study’ of whether the risk of the 2007-2010 drought was enhanced by underlying climate change. They find that there is a climate signal in that drought event. But at no point in the paper is there any analysis of the causes or impacts of drought on wider society or indeed conflict. (italics added)
The Gleick paper has a wide historical account of the use of water in semi-arid and Mediterranean basin countries including the fertile Crescent region, followed by a description of the 2007-10 drought in Syria, with reference to a few newspaper articles on internal migration. [CB: some of these are more substantial, eg reports by The Center for Climate and Security and another by the FAO].
Reviewer: But that paper again does not make the claim in the commentary that leads from climate change to conflict.
CB: These comments are very interesting and I thank the reviewer for them. First, let me declare that my personal interest in climate change and conflict started almost 3 decades ago (when I read a Lancet editorial in 1989 mentioning this possibility) and from 2010-14 I chaired the supervisory panel of the first PhD thesis, to my knowledge, on the topic of climate change, conflict and public health. I thus have a long and deep knowledge of the relevant literature, have met several key figures and have had relevant articles both accepted and rejected, sometimes with extensive debates with editors and reviewers. I also have corresponded extensively with Dr Peter Gleick, referred to by the reviewer.
The literature on this topic is polarised
Both PNAS (which published the paper by Kelley et al) and Weather, Climate and Society (which published Gleick's paper) may have insisted on very nuanced, cautious language, and I recognise that your journal may also. I have therefore, tried to be less assertive in my revision.
However, Gleick writes, in a section called “The role of climate change stresses”:
Gleick: “Water-related conflicts occur in many forms, including disputes over access to water and the control of water systems, the targeting of water infrastructure and systems during conventional conflicts and terrorist actions, and the use of water as a weapon” and “Analysis on the links between possible climatic changes and international security and conflict has been developing for more than two decades, including work on the connections between conflict and stresses from population growth, water scarcity, and agricultural production”.
CB: Gleick, a globally acknowledged expert on water, and a Fellow of the US National Academy of Sciences, is in disagreement with the recently and currently dominant perspective (especially in the political science literature) that conflict does not occur over water; a view, which in my view, is ideological. For example, in late 2014, I attended a lecture by Prof ** (a global leader of the conservative or agnostic view) where he asserted that conflict over water does not occur. At the time ISIS had recently captured control of an important dam, near Mosul in Iraq. This report mentions “The deployment of air power by the US in support of Kurdish forces has shown how seriously the White House takes the potential threat posed by IS control of the dam.”
CB: I asked Prof ** to comment on this apparent counter-example; did it not illustrate an important principle contrary to his general view? Unfortunately, he did not engage with this question.
CB: Threats of war have also been made by senior Pakistani officials against India concerning the Indus Water Treaty for some years (eg "Along the Indus River, saber rattling over water security." Science) including in 2016 and in 2013 by then Egyptian president Mohamed Morsi concerning suggestions to dam the Blue Nile in Ethiopia (eg).
CB: Until the 1980s water competition was considered a trigger for a war involving Israel in 1967 (eg Cooley, J. K. (1984). "(The War Over Water) (a pdf is available here) published in Foreign Policy and cited 209 times according to Google scholar. In parts, it says:
CB: The view that conflict over water is no longer important has in recent years changed. Another widely cited author, Wolf (2007), wrote (in: "Shared waters: conflict and cooperation." Annual Review of Environment and Resources 32: 241-269.)
CB: While Wolf’s paper suggests sympathy for Gleick’s argument his paper referred to above was cited in the most recent IPCC report (in the chapter on Human Security) in support of a more conservative view:
IPCC: "shows strong evidence of significant formal cooperation among river basin riparian states..".
CB: I find this IPCC conclusion (reflected by this extract, and consistent with dominant political science discourse) as ideological, as if to acknowledge the risk of conflict over water might legitimise or perhaps justify war. But there is a counter-view, which I also subscribe to: to suppress the causal link between water scarcity, competition and possible conflict, may instead foster complacency which actually heightens the risk of future conflict. One could argue that the position I hold, which (likely) Prince Charles also does is similarly “ideological”, but one could also argue that each view (i.e. resource scarcity drives co-operation or resource scarcity drives conflict) is valid. I actually believe scarcity can drive co-operation, but beyond a threshold, conflict is more likely (one reason I tried to introduce the concept of thresholds in the original version of the paper). I believe competition over limited resources is fundamental to the theory of evolution, and also consistent with “common sense” (imagine 15 strangers arrive at your house for dinner tonight, or, if that does not disturb you, imagine 150 strangers who are very hungry.)
Gleick: “In the current civil war, some analysts have argued that factors related to drought, including agricultural failure, water shortages, and water mismanagement, have played an important role in contributing to the deterioration of social structures and spurring violence (Femia and Werrell 2013; FAO 2012; Mhanna 2013). In particular, the combination of very severe drought, persistent multiyear crop failures, and the related economic deterioration led to very significant dislocation and migration of rural communities to the cities. These factors further contributed to urban unemployment and economic dislocations and social unrest.” (bold italics added)
Gleick: ”That cable (by the US embassy in Syria in 2008) describes a briefing by FAO Syrian Representative Abdullah bin Yehia on drought impacts, which he described as a ‘‘perfect storm’’ when combined with other economic and social pressure. Concerns expressed at that time also noted that the population displacements ‘‘could act as a multiplier on social and economic pressures already at play and undermine stability in Syria.’
Gleick: "The Syrian conflict that began in 2012 has many roots, including long-standing political, religious, and social ideological disputes; economic dislocations from both global and regional factors; and worsening environmental conditions."
CB: This paper thus argues that key environmental factors for conflict include both direct and indirect consequences of water shortages, ineffective watershed management, and the impacts of climate variability and change on regional hydrology.
CB: However, I disagree with Reviewer 2’s interpretation of Gleick’s paper, which in my view (as I have tried to show) clearly links climate change to the worsening drought and in turn links that to conflict.
CB: Gleick also wrote a paper about this topic in the non-peer-reviewed literature (Gleick, P. (2014). "Drought, Water and Agricultural Management, and Climatic Conditions as Factors in the Syrian Conflict." Huffington Post.) In this, he wrote, in part:
Gleick: “The drastic decrease in water availability, water mismanagement, agricultural failures, and related economic deterioration contributed to Syria's population dislocations and the migration of rural communities to nearby cities. These factors further contributed to urban unemployment, economic dislocations, food insecurity for more than a million people, and subsequent social unrest.” (emphasis added).
CB: Kelley and three co-authors in the PNAS (2015) paper cover some similar territory to Gleick. Contrary to the opinion of the reviewer, they also link the recent drought in Syria not only to climate change, but also to conflict, for example, in their abstract they conclude:
Kelley et al: “Analyses of observations and model simulations indicate that a drought of the severity and duration of the recent Syrian drought, which is implicated in the current conflict, has become more than twice as likely as a consequence of human interference in the climate system.”
CB: Evidence that there is no causal link is even weaker than the converse. And, again, I dispute the reviewer’s assertion that Kelley et al would not support the claim that “a growing number of authors have argued that climate change aggravated the Syrian drought which in turn helped to precipitate the bitter civil war”.
CB: Kelley et al's paper has a summary box. In part it reads:
“There is evidence that the 2007−2010 drought contributed to the conflict in Syria. It was the worst drought in the instrumental record, causing widespread crop failure and a mass migration of farming families to urban centers. Century-long observed trends in precipitation, temperature, and sea-level pressure, supported by climate model results, strongly suggest that anthropogenic forcing has increased the probability of severe and persistent droughts in this region, and made the occurrence of a 3-year drought as severe as that of 2007−2010 2 to 3 times more likely than by natural variability alone. We conclude that human influences on the climate system are implicated in the current Syrian conflict."
Kelley et al: "Our thesis that drought contributed to the conflict in Syria draws support from recent literature establishing a statistical link between climate and conflict (25–27).
CB: I am aware of this statistical work, but have not cited it in my paper, not only due to lack of space, but also because I am aware of methodological criticisms of some of these papers that seem plausible to me (i.e. here I am less supportive than Kelley et al).
Kelley et al: “A more fundamental objection (27) is that data-driven methods do not provide the causal narrative needed to anoint a “theory” of civil conflict, and the quantitative work on climate and conflict has thus far not adequately accounted for the effects of poor governance, poverty, and other sociopolitical factors.”
CB: This is probably true. That is, quantitative work on the topic of climate and conflict is problematic, not least as climate change may either improve or harm resource availability. But this does not negate the possibility that adverse climate change may exacerbate resource scarcity, and in some cases fuel conflict. That pathway is, to me, highly plausible on theoretical grounds, and also empirically, where climate change reduces resource availability. Were climate change to increase resource availability (e.g. crop yield in some favourable locations with suitable soil) then it could plausibly reduce conflict, though again this likelihood must be quantified, for example such a benefit could be negated by poor governance, or if more resources attract in-migration which causes tension.
CB: Finally, though it may not convince the reviewer, Kelley et al recount:
"in a recent interview (45), a displaced Syrian farmer was asked if this was about the drought, and she replied, “Of course. The drought and unemployment were important in pushing people toward revolution. When the drought happened, we could handle it for two years, and then we said, ‘It’s enough.’”
CB: This is common sense, albeit “only” an anecdote. But if the view is commonly held, then it is plausible it points to a causal factor. We need strong evidence to support the alternative hypothesis – such evidence is lacking.
In summary, thank you for reading this carefully. I believe I have presented a very thorough case for publication and I believe this is an extremely important issue for global and planetary health. Although I believe the revised paper is now clear, if succinct, I would of course be willing to undertake additional revision.
This debate matters a great deal. If the link between climate change and conflict is denied then it would follow that we need not be very concerned .. simply spread air conditioning (for heatwaves) or insecticides (for vector borne diseases). Actually, it is ridiculous to dispute the link between climate change, drought and conflict, at least where regional limits to growth are close.