Climate change and conflict combine to deepen global health crises

The combined impact of climate change and conflict "can produce synergistic effects, leading to more severe and complex outcomes," warn experts in The BMJ's climate issue today.

From 1995 to 2015, more than 10 million child deaths were attributed to conflict, while women of reproductive age in high intensity conflict zones experienced mortality rates three times higher than those in peaceful areas, they explain.

Additionally, over 60,000 heat related deaths occurred in 32 European countries during both the exceptionally hot summers of 2022 and 2024, with women substantially more affected than men.

Beyond direct loss of life, climate and conflict hazards also threaten health indirectly, by damaging health infrastructure and disrupting supply chains, as well as by reducing access to food and essential services, escalating the risk of undernutrition and spread of infectious diseases.

They say climate action-both mitigation and adaptation-is critical for tackling climate related risks to health, but conflicts often disrupt these efforts and divert resources away from climate priorities.

Mitigation efforts-critical for reducing long term climate change risks-face similar challenges. Following Russia's invasion, for instance, Ukraine's mitigation investments were substantially reduced as funds shifted to war and reconstruction.

What's more, military activities are themselves a major, but under-reported source of greenhouse gas emissions, they add, conservatively estimated at 5.5% of the global total, with the United States as the largest contributor.

"To promote sustainable development and peace in a changing climate, decision makers-from local to international-must recognise the interplay between climate, health, and conflict and commit to scaling up climate action including in fragile and conflict affected states, " they write.

Science can also play a vital role in supporting decision making, they say.

One promising example is the Climate Conflict Vulnerability Index, which identifies areas where climate and conflict hazards intersect with social vulnerabilities, including health, and could reinforce each other.

"Only by integrating climate action with conflict prevention and peacebuilding can we disrupt the vicious cycle of escalating climate impacts, deteriorating health, and rising instability. Strengthening health systems must be central to these efforts," they conclude.