Mercury: Emissions
Why nobody has measured mercury's carbon footprint
Why nobody has measured mercury's carbon footprint What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions.Per t of elemental mercury, cradle-to-gate. Intensity: not available. Global total: Derived bound from USGS MCS 2026 and World Mining Data 2026.
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | not quantified: underground and open-pit cinnabar mining | – | diesel, explosives | Gold mines that capture by-product mercury allocate little burden to it | USGS MCS 2026 (qualitative) |
| Refining / processing | not quantified: retorting or furnace roasting of ore at several hundred degrees, condensing vapour | – | coal, wood or fuel oil for roasting | Small Chinese and Central Asian furnaces also release mercury vapour | USGS MCS 2026 (qualitative) |
| Movement | negligible per tonne | – | flasks by container and truck, often informally | Not material for carbon | Qualitative |
| Usage | no direct CO2; artisanal gold mining releases about 838 t of mercury to air a year | – | amalgam burning in artisanal gold mining, VCM catalysts, chlor-alkali | Usage is where mercury does most harm | UNEP Global Mercury Assessment 2018 via USGS MCS 2026 |
| Recycling / end of life | rising: retorting of lamps, dental amalgam, thermostats and chlor-alkali cells | – | eight US facilities, Japan recovered 65 t in 2016 | Export bans in the US and EU mean recovered mercury goes to permanent storage | USGS MCS 2026; J. Material Cycles and Waste Management (2023) |
Other environmental impacts
Global anthropogenic mercury emissions to air were about 2,220 t in 2015: artisanal gold mining 838 t, coal combustion 474 t, non-ferrous metals 327 t, cement 233 t, waste 147 t. Mercury converts to methylmercury and builds up in fish.
Levers to cut emissions
- Replace mercury in artisanal gold mining with gravity, borax or cyanide-leach methods under Minamata national action plans
- Mercury-free catalysts for China's coal-based vinyl chloride industry
- Close remaining mercury-cell chlor-alkali plants and store the mercury safely
- Flue-gas controls at coal plants and smelters, which capture mercury and turn it into a by-product for storage
India
India produces no primary mercury but was the largest importer in 2016 (349 t) and took 19.9% of world import value in 2024. Its coal-fired power plants are a major mercury emitter, and the 2015 emission norms for coal plants set a mercury limit of 0.03 mg/Nm3.
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.