On climate, conflict and cumulation: Suggestions for integrative cumulation of knowledge in the research on climate change and violent conflict

Possible links between climate change and intra-state violent conflict have received major scholarly attention in recent years. But with few exceptions there is still a low level of consensus in this research field. The article argues that one reason for this disagreement is a lack of integrative cumulation of knowledge. Such an integrative cumulation is prevented by three obstacles, which have until now hardly been discussed in the literature. The first is the use of inadequate terms, discussed here with a focus on the labels ‘Malthusian’/‘cornucopian’ and the operationalization of key variables. Secondly, the weaknesses of large-N studies in research on climate change and violent conflict are not sufficiently reflected. These include a lack of data on crucial concepts as well as deficits of widely used datasets. Thirdly, literature that deals with a possible link between adverse environmental change and peace (termed here ‘environmental peace perspective’) has neither been systematized nor adequately considered in the debate so far. The article provides examples of these shortcomings and makes suggestions of how to address each of them. It also develops an integrative theoretical framework for the environmental peace perspective which facilitates its consideration in research on climate change and violent conflict

Random acyclic networks

Directed acyclic graphs are a fundamental class of networks that includes citation networks, food webs, and family trees, among others. Here we define a random graph model for directed acyclic graphs and give solutions for a number of the model's properties, including connection probabilities and component sizes, as well as a fast algorithm for simulating the model on a computer. We compare the predictions of the model to a real-world network of citations between physics papers and find surprisingly good agreement, suggesting that the structure of the real network may be quite well described by the random graph.Comment: 4 pages, 2 figure

Violent climate or climate of violence? Concepts and relations with focus on Kenya and Sudan

Addressing deficits of current research on the link between climate change and violent conflict, this article aims to contribute to a more systematic understanding of the violence concept in the context of environmental change. We present a theoretical framework and potential pathways between climate change and violence and an agent-based approach to assess the interplay between capabilities and motivations for violence and the conditions for conflicting or cooperative interactions. Acting as a ‘threat multiplier’, climate change could exceed adaptive capacities and undermine the livelihoods of communities. In the most affected regions, the erosion of social order and state failure as well as already ongoing violent conflicts could be aggravated, leading to a spiral of violence that further dissolves societal structures. Against this background we analyse case studies in Kenya and Sudan, focusing on factors driving or preventing a spiral of violence. While interpastoral conflicts in north-western Kenya result in limited numbers of casualties, the Darfur conflict has been shaped by the civil war in Sudan, involving the government, rebel forces and militias, causing significant loss of lives and destruction. The impact of climate change is less direct in Sudan than in Kenya. To avoid a spiral of violence, in both cases it is essential to reduce socio-economical marginalisation, develop resource-sharing mechanisms and restrain access to arms as part of long-term strategies for a sustainable and peaceful intervention to contain the adverse impacts of climate change

School textbooks, peace and conflict: An introduction

The aim of this article, and of the special issue it introduces, is to claim a more prominent role for the analysis of school textbooks when studying peace and conflict. School textbooks can contribute to several core discussions in this research field because they are indicators of dominant political knowledge, have privileged access to a large audience, and are objects of peace and conflict processes themselves. We reflect how the analysis of school textbooks has already contributed significantly to peace and conflict studies and outline avenues for further research

Conflict and cooperation in the water-security nexus: A global comparative analysis of river basins under climate change

Adequate fresh water availability is an important factor for human security in many parts of the world. In transboundary river basins, decreased water supply due to local environmental change and global climate change and increased water demand due to growing populations and continued economic development can aggravate water scarcity. Contrary to the claim that water scarcity may result in an increased risk of armed conflict, there is no simple relationship between freshwater availability and violent conflict. Other crucial factors need to be taken into consideration that also directly influence resource availability and personal human well‐being. In this review, we assess the scientific literature on conflict and cooperation in transboundary river systems. Most international river basins are already jointly managed by the riparians, but successful management in times of climate change necessitates the inclusion of more factors besides mere allocation schemes. On the basis of a substantial body of literature on the management of transboundary watersheds, an analytical framework of the water‐security nexus is developed that integrates the physical and socioeconomic pathways connecting water availability with conflict or cooperation. This framework is subsequently applied to two transboundary river basins—the Nile River and the Syr Darya/Amu Darya—as they represent two world regions that could become future water hot spots. An improved understanding of the developments leading to water conflicts and their interaction can help to successfully reduce the risk of water conflicts in these regions and to move toward increased cooperation among the riparians of transboundary river systems

Earthquake forecasting based on data assimilation: sequential Monte Carlo methods for renewal point processes

Data assimilation is routinely employed in meteorology, engineering and computer sciences to optimally combine noisy observations with prior model information for obtaining better estimates of a state, and thus better forecasts, than achieved by ignoring data uncertainties. Earthquake forecasting, too, suffers from measurement errors and partial model information and may thus gain significantly from data assimilation. We present perhaps the first fully implementable data assimilation method for earthquake forecasts generated by a point-process model of seismicity. We test the method on a synthetic and pedagogical example of a renewal process observed in noise, which is relevant for the seismic gap hypothesis, models of characteristic earthquakes and recurrence statistics of large quakes inferred from paleoseismic data records. To address the non-Gaussian statistics of earthquakes, we use sequential Monte Carlo methods, a set of flexible simulation-based methods for recursively estimating arbitrary posterior distributions. We perform extensive numerical simulations to demonstrate the feasibility and benefits of forecasting earthquakes based on data assimilation

A New Method for Calculating Arrival Distribution of Ultra-High Energy Cosmic Rays above 10^19 eV with Modifications by the Galactic Magnetic Field

We present a new method for calculating arrival distribution of UHECRs including modifications by the galactic magnetic field. We perform numerical simulations of UHE anti-protons, which are injected isotropically at the earth, in the Galaxy and record the directions of velocities at the earth and outside the Galaxy for all of the trajectories. We then select some of them so that the resultant mapping of the velocity directions outside the Galaxy of the selected trajectories corresponds to a given source location scenario, applying Liouville's theorem. We also consider energy loss processes of UHE protons in the intergalactic space. Applying this method to our source location scenario which is adopted in our recent study and can explain the AGASA observation above 4 \times 10^{19} eV, we calculate the arrival distribution of UHECRs including lower energy (E>10^19 eV) ones. We find that our source model can reproduce the large-scale isotropy and the small-scale anisotropy on UHECR arrival distribution above 10^19 eV observed by the AGASA. We also demonstrate the UHECR arrival distribution above 10^19 eV with the event number expected by future experiments in the next few years. The interesting feature of the resultant arrival distribution is the arrangement of the clustered events in the order of their energies, reflecting the directions of the galactic magnetic field. This is also pointed out by Alvarez-Muniz et al.(2002). This feature will allow us to obtain some kind of information about the composition of UHECRs and the magnetic field with increasing amount of data.Comment: 10 pages, 8 figures, to appear in the Astrophysical Journa

Data assimilation insights on selecting the most valuable atmospheric measurements

We discuss how objective guidance on selecting the most valuable atmospheric measurements on future Mars spacecraft missions can be provided through already developed Martian atmospheric data assimilation systems, and in particular through Observing System Simulation Experiments (OSSEs) which are widely used to design instruments for the Earth’s atmosphere