Climate change has emerged as a significant worldwide concern in recent years and has taken center stage in political discourses. In political speeches, metaphors are commonly used to communicate this scientific issue to the public, with the speakers’ attitudes conveyed through them. From this starting point, the current study examines metaphor construction of climate change in thirty-two speeches by political leaders at the 28th Conference of the Parties (COP28) to the United Nations Framework Convention on Climate Change held from November to December 2023. Based on the conceptual metaphor theory, this study applies the framework of critical metaphor analysis and further evaluates metaphors from an ecolinguistic perspective. It is found that multifaceted metaphorical keywords and conceptual metaphors are used in constructing the key concepts in climate change, with the war, force, living being, vehicle, journey, building, commodity, and greenhouse metaphors as the most prevalent ones identified in this study, and they possess various pragmatic purposes in contexts. From the ecolinguistic perspective, metaphors identified in these speeches are generally eco-friendly, building a positive and progressing image of dealing with climate change by these political leaders and nations. This study confirms the crucial function of metaphors in political speeches on climate change to communicate information and influence the audience’s perception of this issue.