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Abstract Mercury (Hg) is a naturally occurring element that has been greatly enriched in the environment by human activities like mining and fossil fuel combustion. Despite commonalities in some carbon dioxide (CO₂) and Hg emission sources, the implications of long‐range climate scenarios for anthropogenic Hg emissions have yet to be explored. Here, we present comprehensive projections of anthropogenic Hg emissions extending to the year 2300 and evaluate impacts on global atmospheric Hg deposition. Projections are based on four Shared Socioeconomic Pathways (SSPs) ranging from sustainable reductions in resource and energy intensity to rapid economic growth driven by abundant fossil fuel exploitation. There is a greater than two‐fold difference in cumulative anthropogenic Hg emissions between the lower‐bound (110 Gg) and upper‐bound (235 Gg) scenarios. Hg releases to land and water are approximately six times those of direct emissions to air (600–1,470 Gg). At their peak, anthropogenic Hg emissions reach 2,200–2,600 Mg a⁻¹sometime between 2010 (baseline) and 2030, depending on the SSP scenario. Coal combustion is the largest determinant of differences in Hg emissions among scenarios. Decoupling of Hg and CO₂emission sources occurs under low‐to mid‐range scenarios, though contributions from artisanal and small‐scale gold mining remain uncertain. Future Hg emissions may have lower gaseous elemental Hg (Hg⁰) and higher divalent Hg (Hg^II), resulting in a higher fraction of locally sourced Hg deposition. Projected reemissions of previously deposited anthropogenic Hg follow a similar temporal trajectory to primary emissions, amplifying the benefits of primary Hg emission reductions under the most stringent mitigation scenarios. 

ABSTRACT Research in geocryology is currently principally concerned with the effects of climate change on permafrost terrain. The motivations for most of the research are (1) quantification of the anticipated net emissions of CO₂and CH₄from warming and thaw of near‐surface permafrost and (2) mitigation of effects on infrastructure of such warming and thaw. Some of the effects, such as increases in ground temperature or active‐layer thickness, have been observed for several decades. Landforms that are sensitive to creep deformation are moving more quickly as a result, andRock Glacier Velocityis now part of the Essential Climate VariablePermafrostof the Global Climate Observing System. Other effects, for example, the occurrence of physical disturbances associated with thawing permafrost, particularly the development of thaw slumps, have noticeably increased since 2010. Still, others, such as erosion of sedimentary permafrost coasts, have accelerated. Geochemical effects in groundwater from trace elements, including contaminants, and those that issue from the release of sediment particles during mass wasting have become evident since 2020. Net release of CO₂and CH₄from thawing permafrost is anticipated within two decades and, worldwide, may reach emissions that are equivalent to a large industrial economy. The most immediate local concerns are for waste disposal pits that were constructed on the premise that permafrost would be an effective and permanent containment medium. This assumption is no longer valid at many contaminated sites. The role of ground ice in conditioning responses to changes in the thermal or hydrological regimes of permafrost has re‐emphasized the importance of regional conditions, particularly landscape history, when applying research results to practical problems.