Raleigh, Clionadh, and Henrik Urdal. 2007. Climate change, environmental degradation and armed conflict. Political Geography 26, no. 6 (August): 674-694. doi:10.1016/j.polgeo.2007.06.005.
From Abstract: "Climate change is expected to bring about major change in freshwater availability, the productive capacity of soils, and in patterns of human settlement. However, considerable uncertainties exist with regard to the extent and geographical distribution of these changes...We argue that our best guess about the future has to be based on our knowledge about the relationship between demography, environment and violent conflict in the past...This article represents a new approach to assess the impact of environment on internal armed conflict by using georeferenced...data and small geographical, rather than political, units of analysis. It addresses some of the most important factors assumed to be strongly influenced by global warming: land degradation, freshwater availability, and population density and change. While population growth and density are associated with increased risks, the effects of land degradation and water scarcity are weak, negligible or insignificant. The results indicate that the effects of political and economic factors far outweigh those between local level demographic/environmental factors and conflict" (674).
"To address the issue of whether climate change poses a traditional security threat, we build on propositions from the environmental security literature, identifying potential links between natural resource scarcity and violent conflict. We combine these propositions with environmental change scenarios from...[IPCC]...and develop testable hypotheses about the expected relationships...If soil degradation, freshwater scarcity and population pressure have influenced the risk of conflict in the past, we assume that this may also inform us about likely security implications of climate change. Obvious limitations to such approach are the possibilities that climate change will bring about more severe and more abrupt forms of environmental change than we have experienced in the past" (675).
While the lion's share of studies on the relationship between resource scarcity and conflict focus on state-based units, this study will focus on 100 square kilometer blocks.
The existing literature on resource scarcity and conflict focuses on the following causal chains: "firstly, increasing temperatures, precipitation anomalies and extreme weather is expected to aggravate processes of resource degradation that is already underway" (676). "Secondly, significantly increasing sea levels as well as more extreme weather conditions will force millions of people to migrate, potentially leading to higher pressures on resources in areas of destination and subsequently to resource competition" (677).
Their soil data: "The measure of soil degradation throughout the world was commissioned by the International Soil Reference and Information Centre. The information...is based on questionnaire answers from numerous soil experts throughout the world" (683).
"It appears from this disaggregated analysis that demographic and environmental variables only have a very moderate effect on the risk of civil conflict" (689).
Showing posts with label Precipitation Change. Show all posts
Showing posts with label Precipitation Change. Show all posts
Wednesday, December 30, 2009
Hendrix and Glaser: Trends and Triggers
Hendrix, Cullen S., and Sarah M. Glaser. 2007. Trends and triggers: Climate, climate change and civil conflict in Sub-Saharan Africa. Political Geography 26, no. 6 (August): 695-715. doi:10.1016/j.polgeo.2007.06.006.
The Abstract: "The conventional discourse relating climate change to conflict focuses on long term trends in temperature and precipitation that define ecosystems and their subsequent impact on access to renewable resources. Because these changes occur over long time periods they may not capture the proximate factors that trigger conflict. We estimate the impact of both long term trends in climate and short term climatic triggers on civil conflict onset in Sub-Saharan Africa. We find that both operationalizations have a significant impact. Climates more suitable for Eurasian agriculture are associated with a decreased likelihood of conflict, while freshwater resources per capita are positively associated with the likelihood of conflict. Moreover, positive changes in rainfall are associated with a decreased likelihood of conflict in the following year. We also assess the outlook for the future by analyzing simulated changes in precipitation means and variability over the period 2000-2099. We find few statistically significant, positive trends in our measure of interannual variability, suggesting that it is unlikely to be affected dramatically by changes in climate" (695).
There has been much assumed about the link between climate change and conflict, though, "The causal link between climate change and threats to security...is not specified" (696).
One set of literature argues that a decrease in renewable resources will lead to conflict. Another argues that variation in climate will lead to conflict. "We investigate these arguments from two complementary perspectives. First, the effects of climate change on the onset of conflict must be conceived of as (1) long term trends that may lead to a higher baseline probability of conflict, and (2) short term triggers that affect the interannual variability in that probability" (696).
They explore changes in precipitation using the NCAR-PCM model.
"These findings point to two conclusions. The first is that the future for Africa is not necessarily one defined by increasing interannual variability in rainfall, the most significant climatic variable in our analysis of conflict onset. The second regards policy. Our findings suggest that reducing dependence on rainwater for agriculture may mitigate conflict, even as rainfall variability is not predicted to increase over time" (696-7).
Lit Review:
Good review of literature on water availability and conflict.
"Thus framed, we address two open questions in the literature. The first is how to combine stationary trend measures with temporally variant trigger measures in order to model the environmental conditions that lead to conflict. The second regards the neo-Malthusian tendency to assume (a) that resources are dwindling and (b) that fewer resources lead inexorably to conflict" (698).
"...we can generate hypotheses regarding the effects of land degradation, climatic conditions, and freshwater abundance on the likelihood of conflict. Land degradation refers to processes that negatively affect land productivity. If productivity is defined as the expected benefit per unit of effort, then we expect higher levels of land degradation to be associated with lower returns to agriculture and therefore to higher likelihood of conflict, ceterus paribus" (699).
They use PRIO/Uppsala data for their dependent variable.
"Land degradation is defined as the temporary or permanent reduction in the reproductive capacity of land as a result of human action" (701)
"Our findings suggest that interannual variability in rainfall is a more significant determinant of conflict than our measures of climate, land degradation, and freshwater resources. Admittedly, these results may be biased due to stationary in the trend measures, a problem addressed critically in section two but which ultimately proves insurmountable in our analysis due to constraints on available data" (710).
The authors find that the future of Sub-Saharan stability vis-à-vis climate change is relatively positive, as the forecasts to not show large amounts of variability interannual pattern changes. They argue that this is due to a regional bias.
One key take-away from my perspective is that we need to look at interannual variability in forecasts of precipitation.
The Abstract: "The conventional discourse relating climate change to conflict focuses on long term trends in temperature and precipitation that define ecosystems and their subsequent impact on access to renewable resources. Because these changes occur over long time periods they may not capture the proximate factors that trigger conflict. We estimate the impact of both long term trends in climate and short term climatic triggers on civil conflict onset in Sub-Saharan Africa. We find that both operationalizations have a significant impact. Climates more suitable for Eurasian agriculture are associated with a decreased likelihood of conflict, while freshwater resources per capita are positively associated with the likelihood of conflict. Moreover, positive changes in rainfall are associated with a decreased likelihood of conflict in the following year. We also assess the outlook for the future by analyzing simulated changes in precipitation means and variability over the period 2000-2099. We find few statistically significant, positive trends in our measure of interannual variability, suggesting that it is unlikely to be affected dramatically by changes in climate" (695).
There has been much assumed about the link between climate change and conflict, though, "The causal link between climate change and threats to security...is not specified" (696).
One set of literature argues that a decrease in renewable resources will lead to conflict. Another argues that variation in climate will lead to conflict. "We investigate these arguments from two complementary perspectives. First, the effects of climate change on the onset of conflict must be conceived of as (1) long term trends that may lead to a higher baseline probability of conflict, and (2) short term triggers that affect the interannual variability in that probability" (696).
They explore changes in precipitation using the NCAR-PCM model.
"These findings point to two conclusions. The first is that the future for Africa is not necessarily one defined by increasing interannual variability in rainfall, the most significant climatic variable in our analysis of conflict onset. The second regards policy. Our findings suggest that reducing dependence on rainwater for agriculture may mitigate conflict, even as rainfall variability is not predicted to increase over time" (696-7).
Lit Review:
Good review of literature on water availability and conflict.
"Thus framed, we address two open questions in the literature. The first is how to combine stationary trend measures with temporally variant trigger measures in order to model the environmental conditions that lead to conflict. The second regards the neo-Malthusian tendency to assume (a) that resources are dwindling and (b) that fewer resources lead inexorably to conflict" (698).
"...we can generate hypotheses regarding the effects of land degradation, climatic conditions, and freshwater abundance on the likelihood of conflict. Land degradation refers to processes that negatively affect land productivity. If productivity is defined as the expected benefit per unit of effort, then we expect higher levels of land degradation to be associated with lower returns to agriculture and therefore to higher likelihood of conflict, ceterus paribus" (699).
They use PRIO/Uppsala data for their dependent variable.
"Land degradation is defined as the temporary or permanent reduction in the reproductive capacity of land as a result of human action" (701)
"Our findings suggest that interannual variability in rainfall is a more significant determinant of conflict than our measures of climate, land degradation, and freshwater resources. Admittedly, these results may be biased due to stationary in the trend measures, a problem addressed critically in section two but which ultimately proves insurmountable in our analysis due to constraints on available data" (710).
The authors find that the future of Sub-Saharan stability vis-à-vis climate change is relatively positive, as the forecasts to not show large amounts of variability interannual pattern changes. They argue that this is due to a regional bias.
One key take-away from my perspective is that we need to look at interannual variability in forecasts of precipitation.
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