Aligning global mercury mitigation with climate action

Environmental mercury (Hg) pollution affects microbial community structure and functions. Yet, whether and how this influence cascades through microbe-mediated cycling of major greenhouse gases (GHGs) remains poorly understood. This Perspective synthesizes emerging evidence on the Hg-microbe-GHG nexus, exploring the possibility that global Hg emission reductions, while critical for human and planetary health, may cause alterations to microbe-mediated GHG fluxes. Significant knowledge gaps persist, however, regarding the Hg-microbe-GHG nexus, particularly concerning the magnitude and direction of the nexus's net impact on climate and global environmental change. To bridge these gaps, we propose a three-step roadmap aimed at disentangling the potential impacts of global Hg emission mitigation strategies on microbial communities, associated GHG emissions, and subsequent climate change. Collectively, these joint efforts from scientists, industry, community stakeholders, and policymakers are critical to harmonizing global Hg mitigation efforts with climate action and to ensuring a sustainable future for Earth systems and their inhabitants.