Global security crisis and COP31: a duty to accelerate phasing out fossil fuels

Abstract

Seven of the nine planetary boundaries on which we rely to make the earth habitable have been breached, according to the 2026 planetary health check.This breach is the worst ever recorded.1 The effect of surpassing these vital climate tipping points is already being felt everywhere by nature and humanity.The environmental consequences of further breaching these planetary boundaries are unknown, posing a security risk that several European governments are taking seriously.2 Earlier this year, a UK national security assessment detailed the high risk consequences of the collapse of global ecosystems and biodiversity loss.These include food shortages, water scarcity, geopolitical insecurity, and conflict.3 4 In 2021, before the US government became dominated by fossil fuel interests and climate denialism, the US Department of Defence noted that the "unprecedented scale of wildfires, floods, droughts, typhoons, and other extreme weather events . . .contributed to instability around the world" and created substantial security risks.5 The implications are relevant worldwide.At a pre-COP summit held in Fiji on the 5-8 October 2026, Murat Kurum, the Turkish climate change minister and COP31 president said that wealthy countries need to spend more on tackling the climate crisis than on defence, because the climate crisis is "the" security issue.6 Despite the evident security risks posed by the climate crisis, governments are instead focused on global defence spending, which has increased over the past decade.The Stockholm International Peace Research Institute estimates that world military expenditures reached $2887bn in 2025, a 2.9% rise from 2024.7 In 2025, NATO (North Atlantic Treaty Organization) allies pledged to increase defence investments to 5% of gross domestic product , with European allies and Canada increasing their expenditure by 20% above 2024.8 This increase in defence spending comes at a time of geopolitical turmoil, heightened ongoing conflicts such as those in Iran, Ukraine, Gaza, and Sudan, and an increased sense of insecurity worldwide.But spending more on defence means that governments have less to spend elsewhere, such as on health, education, infrastructure, environmental protection, and climate change mitigation and adaptation.9 10

The authors' abstract, as published at the source. BMJ, 2026 · DOI ↗