Future climate change is predicted to diminish essential natural resource availability in many regions and perhaps globally. The resulting scarcity of water, food and livelihoods could lead to increasingly desperate populations that challenge governments, enhancing the risk of intra- and interstate conflict. Defence establishments and some political scientists view climate change as a potential threat to peace. While the medical literature increasingly recognises climate change as a fundamental health risk, the dimension of climate change-associated conflict has so far received little attention, despite its profound health implications. Many analysts link climate change with a heightened risk of conflict via causal pathways which involve diminishing or changing resource availability. Plausible consequences include: increased frequency of civil conflict in developing countries; terrorism, asymmetric warfare, state failure; and major regional conflicts. The medical understanding of these threats is inadequate, given the scale of health implications. The medical and public health communities have often been reluctant to interpret conflict as a health issue. However, at times, medical workers have proven powerful and effective peace advocates, most notably with regard to nuclear disarmament. The public is more motivated to mitigate climate change when it is framed as a health issue. Improved medical understanding of the association between climate change and conflict could strengthen mitigation efforts and increase cooperation to cope with the climate change that is now inevitable.