Sustained drought,vulnerability and civil conflict in Sub-Saharan Africa

With climate change projections indicating a likely future increase in extreme weather phenomena, it is an urgent matter to assess the effect of drought on civil conflict. However, studies of this relationship so far provide inconclusive findings. One reason for this inconsistency is that existing research has not sufficiently taken into account the local vulnerability and coping capacity that condition the effect of drought. In particular, the exposure to sustained droughts undermines alternative coping mechanisms of individuals. Moreover, reliance on rainfed agriculture for income and food provision renders individuals particularly vulnerable to droughts. Based on these observations, I suggest that areas experiencing sustained droughts or depending on rainfed agriculture are more likely to see civil conflict following drought as individuals in these regions are more likely to partake in rebellion in order to redress economic grievances or to obtain food and income. Using novel high-resolution data on civil conflict events in Sub-Saharan Africa from 1989 to 2008, this paper evaluates the relationship between sustained drought, rainfed agriculture and civil conflict violence at the subnational level. In line with the argument, areas with rainfed croplands see an increased risk of civil conflict violence following drought. There is also some support for the proposition that areas experiencing sustained droughts have a higher risk of conflict. The results are robust to a wide range of model specifications.     

Droughts as random events in the Maya lowlands

Because the values of most of the parameters controlling the occurrence and severity of a drought in a given location are unknown, and no periodicity has been observed, droughts can be considered random events. Running a random number generator within the limits of the annual rainfall variability relevant to the Maya lowlands, and defining a “Lean Year”, it is observed that strings of lean years occur quite frequently. Defining “Severe Drought”, “Disaster”, and “Catastrophe” based on the length of these strings, it is observed that a severe drought occurs on average every 32 years, a disaster occurs on average every 130 years, and a catastrophe on average every 500 years. These values fit the measured variability of the Yucatan climate, as observed in lake core sediments and in the post conquest written records. It also fits the average occurrence of “megadroughts” in the US Great Plains.The fit between the random occurrence model and the actual, “measured” occurrence of droughts supports the notion that for all practical purposes, droughts had been random events in the Maya region and could not be predicted. The lack of evident periodicity could be one of the reasons why means for long-term storage of food products were not developed there. It may also have affected the relationship between the priesthood and the general populace in that region.Since the method described here can be applied to any climatic region once the rainfall variability and the sensitivity of the local agriculture are known or can be estimated, if similar results are found they may probably have affected other regions with other ancient cultures in a similar way.     

Droughts,state-citizen relations and support for political violence in Sub-Saharan Africa: A micro-level analysis

Droughts are unlikely to influence support for political violence unless they coincide with unfavourable social and political conditions. In this article I suggest that support for violence in times of drought depends on people's relationship with their government and the way in which this relationship determines their vulnerability to adverse climatic shocks. Droughts impose serious economic pressures on affected people, especially in Sub-Saharan countries, where access to alternative sources of water is often limited. People who enjoy good relations with the sitting regime and who benefit from a wide range of public services are more likely to overcome these pressures. On the other hand, politically neglected, marginalised and disaffected people have many more difficulties in coping with drought and are likely to blame their government for it. This, in turn, can pave the way for endorsing more radical attitudes and even violence against the government and its (presumed) political supporters. The results of my analysis partly confirm this idea. Exposure to drought per se does not seem to influence attitudes towards political violence in a statistically significant way. However, I find both people who are politically discriminated against and people who do not trust their head of state to be more inclined to endorse political violence when hit by severe drought. These findings, which are consistent across a number of alternative model specifications, show that fragile state-citizen relations play an important part in the processes linking drought exposure and support for political violence.     

Paleoenvironmental catastrophies on the Peruvian coast revealed in lagoon sediment cores from Pachacamac

Paleoenvironmental reconstruction combining data from diatom, pollen, macrophytic, and archaeological analyses had not been attempted previously for coastal Peru. We analyzed two radiocarbon-dated sediment cores extracted from the “sacred” Urpi Kocha Lagoon at the pre-Hispanic religious center of Pachacamac (ca. AD 350-1533), near Lima, to characterize the paleoenvironment of the site. The data reveal an environmental history characterized by alternating periods of severe drought and catastrophic flood. Recurrent pulses with distinctive sediment, diatom, pollen, and macrophytic characteristics reflecting variations in water depth, substrate, turbidity and salinity, usually contain a thick basal sandy storm deposit overlain by thin organic accumulations of peat, gyttja, and snails. The most intense of these disturbance pulses, when correlated with pollen, plant macrofossils, radiocarbon dates, and regional proxy data, provide local evidence of four major floods associated with sustained, catastrophic El Niño events, tsunamis and/or severe storms in the Andean highlands over the last 2000 years.     

GIS-based modeling of drought and historical population change on the Canadian Prairies

This article describes the development of a GIS-based model of historical drought and population change in western Canada, designed to support qualitative field research into drought adaptation and migration. The model combines digitized census data and recently available modeled historical climate data at a 10 km² grid cell scale and can be used to generate maps of ‘hotspots’ where historical declines in rural populations may be associated with extended periods of heat and lack of precipitation. The results suggest a promising avenue for expanding and refining GIS-based modeling of historical human–climate interactions to support qualitative research and to potentially serve as a stepping stone toward forecasting future risk areas of drought-related migration in continental dryland areas.     

Parched and impatient: Political engagement after drought

How does local experience of climate change alter voters' policy preferences and voting decisions? After exposure to a climate disaster, voters may elect politicians prioritising robust disaster prevention policies, or conversely, immediate economic relief. In turn, elected representatives will either mitigate or exacerbate the severity of future climate events. In this study, I leverage a climate event with a high degree of local geographic variation – a pre-election drought in Australia – to see how it shaped political beliefs and behaviours in 2019. Using a longitudinal panel survey, I show that voters in drought-exposed areas increasingly prioritised individual economic security, rather than broader climate-mitigation policies. Moreover, I find that regional micro-parties in drought-affected regions gained vote share. In other words, voters at the front-lines of climate change sought out immediate and local economic relief. Unless local politicians can propose climate policies with short-term economic benefits, disasters may limit governments' capacities to pursue long-term climate resilience.     

清代淮河流域旱涝灾害的人为因素分析

本文根据历史文献的记载,对清代淮河流域的水旱灾害进行了量化分析,得出了此时期旱涝灾害发生的基本情况。淮河流域的旱涝灾害有的是纯自然力所为,但更多的是人们利用自然的失当所致。本文主要从人为活动因素即人类的不当行为入手,对清代淮河流域旱涝灾害发生的原因作一初步考察。     

Climate change and the Syrian civil war revisited

For proponents of the view that anthropogenic climate change will become a ‘threat multiplier’ for instability in the decades ahead, the Syrian civil war has become a recurring reference point, providing apparently compelling evidence that such conflict effects are already with us. According to this view, human-induced climatic change was a contributory factor in the extreme drought experienced within Syria prior to its civil war; this drought in turn led to large-scale migration; and this migration in turn exacerbated the socio-economic stresses that underpinned Syria's descent into war. This article provides a systematic interrogation of these claims, and finds little merit to them. Amongst other things it shows that there is no clear and reliable evidence that anthropogenic climate change was a factor in Syria's pre-civil war drought; that this drought did not cause anywhere near the scale of migration that is often alleged; and that there exists no solid evidence that drought migration pressures in Syria contributed to civil war onset. The Syria case, the article finds, does not support ‘threat multiplier’ views of the impacts of climate change; to the contrary, we conclude, policymakers, commentators and scholars alike should exercise far greater caution when drawing such linkages or when securitising climate change.     

Managing the risk of climatic variability in late prehistoric northern Chile

The concept of risk management encompasses the diverse strategies employed in preventing and mitigating losses associated with social and environmental calamities. Building on the growing literature on risk, we use archaeological data from the Tarapacá Valley, located in northern Chile, to document the risk-reduction tactics mobilized by the valley’s inhabitants to navigate the increasingly volatile environmental and social conditions of the Late Intermediate Period (AD 1000–1450). With the onset of exceptionally unpredictable environmental conditions after AD 1100, residents of the Tarapacá Valley chose strategies such as increased trade and agricultural diversification and extensification to minimize shortages in staple resources. Threats of raiding and intra-community strife exacerbated the risks associated with subsistence shortfalls. Valley communities elected a number of strategies to curtail conflict-induced risk, including movement of settlements and field systems to defensible locations, construction of walls and other defensive features, and the introduction of plazas. Rock art data suggest that trade was increasingly embedded in ritually sanctioned events involving groups from different ecological zones. While studies of risk have focused disproportionately on environmental hazards, subsistence-related crises are often compounded by social hazards that require their own risk-mitigating strategies, further constraining options for coping with subsistence stress.