NATO’s 2022 Strategic Concept defines climate change as a “crisis and a threat multiplier”, but what does that actually mean for NATO’s ability to deter and defend? At the NATO Summit in Brussels in 2021, Allies agreed to put climate change at the top of NATO’s agenda, endeavouring to become the leading international organisation when it comes to understanding and adapting to the impact of this epochal phenomenon on security. The new Strategic Concept, which was agreed at the 2022 Madrid Summit, reaffirmed this commitment. Since then, NATO has produced several flagship reports on the topic, which show how the effects of climate change have profound impacts on everyday life. However, there is still a strong need to explore how climate change affects NATO operations across different domains.