- The Third and Fourth Assessment Reports of the IPCC have been criticized for a shallow discussion of the possible impact of climate change on conflict.
- The Fifth Assessment Report represents a major improvement, and the Human Security chapter in particular.
- However, there are several inconsistencies between the various chapters and some of these seem to be related to varying authorship.
- The lack of a clear probability assessment in causal statements is another major problem.
Violence seems to be on a long-term decline in the international system. The possibility that climate change would create more violent conflict was mentioned in scattered places in the Third and Fourth Assessment Reports from the Intergovernmental Panel on Climate Change (IPCC), published in 2001 and 2007 respectively. The empirical literature testing for relationships between climate change and various forms of conflict has undergone a major expansion since then. The report from Working Group II of the Fifth Assessment Report contains a much more careful assessment of the climate change-conflict nexus. The Human security chapter reports high agreement and robust evidence that human security will be progressively threatened as the climate changes. But as far as the impact on armed conflict is concerned, it paints a balanced picture, concluding that while individual studies vary in their conclusions, ‘collectively the research does not conclude that there is a strong positive relationship between warming and armed conflict’. The chapter also argues that climate change is likely to have an influence on some known drivers of conflict, and this point is reiterated in other chapters as well as the Technical summary and the Summary for policymakers. A chapter on ‘Emergent trends …’ has a somewhat more dramatic conclusion regarding a climate-conflict link, as does the Africa chapter, while a methods chapter on ‘Detection and attribution’ dismisses the climate-change-to-violence link. The entire report is suffused with terms like ‘may’, ‘has the potential to’, and other formulations without any indication of a level of probability. Overall, the Fifth Assessment Report of the IPCC does not support the view that climate change is an important threat to the long-term waning of war. Still, the report opens up for conflicting interpretations and overly alarmist media translations.