Mining Decarbonization: Where the Emissions Actually Are, and Where to Spend First

Ninety-three percent of the mining and metals sector's emissions are Scope 1, generated on site. Seven percent are Scope 2, from purchased electricity.

That 13-to-1 ratio decides where decarbonization capital should go. It means on-site operational change outweighs grid renewable procurement for most operators, which is the opposite of how many corporate sustainability programmes are structured.

Within those on-site emissions, diesel dominates. The International Council on Mining and Metals puts diesel-powered mining vehicles at 30 to 80 percent of direct emissions at a mine site, depending on geography and commodity, and haul trucks alone account for roughly half of all direct mine-site emissions.

There is also a correction worth making at the outset. The sector's emissions are concentrated in steel, aluminium and coal, which together account for 93 percent of the total. Non-coal mining contributed only 0.54 percent of global greenhouse gas emissions in 2024.

This guide covers where the emissions actually sit, what each decarbonization lever delivers, what it does to your electrical system, and which parts of mining sustainability sit outside an energy provider's scope.

Where Mining Emissions Actually Are

The mining and metals sector was responsible for 11 percent of global greenhouse gas emissions in 2024, split 3 percent from mining activities and 8 percent from metal production.

That places it sixth among global emissions sources, behind power generation, transport and agriculture, and roughly level with all other industrial processing activities combined.

The figures come from the ICMM's Global Mining and Metals Greenhouse Gas Emissions Dataset, built from facility-level data across 1,700 facilities and 14 commodities, representing 87 percent of global production, with the remaining 13 percent modelled using regional commodity-level averages.

The scope split that decides capital allocation

Of the sector's total, 93 percent are Scope 1 emissions generated on site, totaling 5.5 Gt CO2 equivalent. The remaining 7 percent, or 0.4 Gt CO2 equivalent, are Scope 2 emissions from purchased electricity.

Scope 1 covers direct emissions from sources the operator owns or controls, including diesel combustion in mobile equipment, on-site generation and fugitive releases. Scope 2 covers indirect emissions from purchased electricity. Scope 3 covers everything else in the value chain, upstream and downstream, and for most miners it dwarfs Scope 1 and 2 combined.

The 13-to-1 ratio between Scope 1 and Scope 2 means capital allocation must emphasis on-site operational modification rather than grid-based renewable energy procurement.

That is the single most useful instruction in the dataset, and it runs against the instinct to buy renewable energy certificates first because they are the easiest purchase to make.

Energy intensity

Mining accounts for about 2 percent of global energy use, which is modest relative to its emissions share and reflects how much of the sector's footprint is concentrated in metal processing rather than extraction.

The trend

Between 2020 and 2024, overall greenhouse gas emissions from mining and metals rose by 3 percent, driven by increased mining intensity and surging global demand.

By Commodity: The Breakdown That Changes the Conversation

Sector emissions are concentrated in three commodities, and a copper or lithium operation's decarbonization problem is not the same problem a steel mill has.

Steel, aluminium and coal together account for 93 percent of sector Scope 1 and 2 emissions.

The coal fugitive emissions problem

Fugitive emissions from coal mining account for 82 percent of all mining-related Scope 1 and 2 emissions, representing roughly 2 percent of total global greenhouse gas output.

Fugitive emissions are gases released during extraction and handling rather than burned as fuel, principally methane liberated from coal seams. They are a methane capture and destruction problem rather than an energy problem, and they are not addressed by electrification or renewable power.

The finding that complicates the usual narrative

Non-coal mining made up only 0.54 percent of global greenhouse gas emissions in 2024.

Mining for the minerals needed in the energy transition is a small emitter. The real decarbonization opportunity at sector level sits in steelmaking and aluminium smelting, which are metal production rather than mining.

What this means for an individual operator

Your position depends entirely on what you mine and what you do with it. An operator running an aluminium smelter has an electricity problem. A coal operation has a fugitive methane problem. A copper or lithium mine has a diesel problem.

Diesel: The Dominant On-Site Source

• Diesel-powered mining vehicles account for 30 to 80 percent of direct emissions at a mine site, depending on site geography and the commodity being mined.
• That range comes from the ICMM, and the spread is wide because an underground gold mine and an open pit iron ore operation have very different fleet profiles.
• Haul truck diesel combustion generates roughly 50 percent of all direct mine-site emissions, which makes it the clearest single target for intervention.

The equipment-level breakdown

• Research into surface mining operations found haul trucks the single biggest source of mine emissions at 35 percent of the total, with crushers at 20 percent, bulldozers at 7 percent and excavators at 5 percent.
• The same analysis put Scope 1 from diesel in mobile equipment at 40 to 50 percent of current mine CO2 emissions, and Scope 2 from non-renewable electricity at 30 to 35 percent.

The scale of the fleet

There are around 28,000 large mine hauling trucks in operation globally. They collectively emit over 69 million tonnes of CO2 as Scope 1, with an additional 15 Mt CO2 as Scope 3, based on consumption of 25 billion litres of diesel fuel.

Why this concentration is useful

A problem concentrated in one equipment class is a tractable problem. Addressing haul trucks addresses roughly half of direct emissions, and the technologies to do it exist and are deploying.

Electrification: Battery Fleets and Trolley Assist

Replacing diesel with electricity is the single largest decarbonization lever available at mine site level, and two approaches dominate.

Battery electric vehicles replace the diesel engine entirely. Battery electric load-haul-dump machines and underground trucks eliminate diesel particulate matter and recover energy through regenerative braking rather than losing it as friction heat.

Trolley assist feeds electrical power to haul trucks through an overhead line during the loaded uphill haul, which is the most energy-intensive phase of the cycle. A pantograph on the truck contacts the line, providing propulsion power rather than generating it on board.

What trolley assist delivers

• Trolley assist systems for haul trucks reduce diesel consumption by 30 to 50 percent.
• It targets the specific phase where a haul truck burns most of its fuel, without requiring the truck to carry a large battery, and it works on fixed routes, which is what a haul road is.

Where each fits

• Battery electric fleets suit underground operations and shorter haul cycles, where the ventilation benefit compounds the direct fuel saving.
• Trolley assist suits surface operations with long, steep, fixed haul roads, where the uphill loaded haul dominates fuel consumption.
• Many operations will use both. For the electrical engineering behind each, including the charging load and the trolley line fault behavior.

The barrier that is not technical

The most frequently cited obstacle to electrification is not the equipment. It is the shortage of technicians, trainers and mining engineers experienced with high-voltage systems. A battery electric fleet brings high-voltage work into a maintenance organization built around diesel engines and hydraulics.

Alternative Fuels

• Where electrification is not yet viable, fuel substitution delivers meaningful Scope 1 reduction without replacing the fleet.
• Biofuel adoption can cut Scope 1 emissions by 40 to 60 percent depending on fuel specifications.
• Hydrotreated vegetable oil, or HVO, is a renewable diesel that can run in most existing compression ignition engines with limited or no modification, which makes it a transitional option rather than a capital programme.

Hydrogen is being trialled in mining haulage, with the first hydrogen-powered haul truck unveiled in 2021. It remains at demonstration scale and depends on hydrogen production and distribution infrastructure that does not yet exist at most mine sites.

How to weigh them

• Biofuels deliver a partial reduction immediately with minimal capital. Electrification delivers a larger reduction with substantial capital and a longer programme. Hydrogen delivers neither yet.
• Most operators will sequence them: fuel substitution now, electrification as fleet replacement cycles arrive, hydrogen only if the infrastructure materialises.

The Ventilation Dividend

• Removing diesel from an underground fleet reduces the ventilation load, and ventilation is one of the largest electrical consumers in an underground mine.
• Ventilation alone can account for up to 49 percent of a mine's energy consumption.
• The mechanism is direct. Ventilation exists partly to dilute and remove diesel particulate matter, carbon monoxide, nitrogen oxides and engine heat. Electric machines produce none of the exhaust and far less heat, so the required airflow falls.

Why this changes the business case

Fleet electrification is usually evaluated on fuel saved. The ventilation reduction is a second, separate saving on a load that is often larger than the fleet's own electrical demand.

Scope 2 and Renewable Integration

• Scope 2 emissions come from purchased electricity, and three mechanisms address them with very different physical effects.
• On-site generation physically supplies the mine. Solar, wind and storage installed at site displace grid or diesel-generated power directly.
• A power purchase agreement contracts for renewable energy delivered to the grid, usually elsewhere. It changes the emissions accounting and does not change what arrives at the mine.
• Renewable energy credits represent the environmental attributes of renewable generation, purchased separately from the electricity. They offset reported emissions and deliver no physical power.

What renewable fraction is achievable

Published off-grid mine projects suggest roughly 20 percent renewable fraction for solar plus storage, and around 50 percent where wind is added. Agnew Gold Mine in Australia runs a 56 MW off-grid system combining solar, wind, diesel or gas and battery at roughly 50 percent renewable fraction.

The limitation that matters

• Scope 2 is 7 percent of sector emissions. A programme that achieves 100 percent renewable electricity and leaves the diesel fleet untouched has addressed the smaller share.
• That is not an argument against renewable procurement. It is an argument for sequencing it correctly, and for not confusing a carbon accounting measure with an operational change.

Where Scope 2 does dominate

Aluminium smelting is electricity-intensive, which makes renewable electricity the primary lever rather than a secondary one. Aluminium production accounts for 15 percent of sector emissions and is one of the clearest opportunities for reduction through renewable power.

Energy Efficiency in Processing

Comminution, the crushing and grinding of ore, accounts for 50 to 80 percent of a mine's energy consumption, which makes it the largest single target for electrical efficiency work.

Energy reduction of 30 to 50 percent is considered achievable in comminution through circuit design and equipment selection.

Because comminution dominates the electrical load, a percentage saved there outweighs the same percentage saved anywhere else on site. It is a Scope 2 measure where power is purchased, and a Scope 1 measure where power is generated on site from diesel or gas.

The Power Consequence Nobody Budgets For

• Every decarbonization lever on this list increases electrical load, and most mine power systems were not designed for it.
• Electrifying a haul fleet converts diesel consumption into electrical demand. The energy formerly delivered by a fuel truck now arrives through the substation.

What has to change

• Charging infrastructure sized to the fleet and the duty cycle, with the charging load scheduled against the mill and the ventilation load rather than added on top of the peak.
• Distribution capacity, because a mine network designed for comminution and ventilation does not have headroom for a large new load without reinforcement.
• Generation capacity, particularly on off-grid sites, where the fleet's energy has to come from somewhere and that somewhere is the site power plant.

If the site is off-grid

• The problem compounds. Off-grid mines generate everything they consume, so electrifying the fleet moves fuel from the haul trucks to the power station rather than removing it.
• The emissions benefit only materializes if the generation is lower-carbon than the diesel it replaced. Electrifying onto a diesel microgrid moves emissions; it does not remove them.
• That is why electrification and renewable integration are pursued together on off-grid sites rather than sequentially.

Grid-connected sites

Where a connection exists, the question is available capacity and the carbon intensity of the supply. A fleet electrified onto coal-fired grid power may show little or no Scope 1 and 2 improvement on a combined basis.

Staffing

On-site generation and high-voltage charging infrastructure both require operating capability. Budget the competency alongside the equipment, because the skills gap is the most commonly cited barrier to electrification.

For mine load profiles, off-grid configurations and the electrical design implications, see our guide to powering a mine. For generation technology selection, see our guides to power generation equipment compared and gas turbine or reciprocating engine selection.

The Frameworks That Govern This

Mining has more developed sustainability frameworks than most industrial sectors, and a decarbonization programme is assessed against them rather than against general principles.

ICMM members are committed to reaching net zero Scope 1 and 2 emissions by 2050 and to supporting reductions in Scope 3.

Why the framework matters commercially

Offtake agreements, project finance and insurance increasingly reference these standards. An operator pursuing a decarbonization programme is usually doing so against a commitment with a reporting obligation attached, not as a discretionary initiative.

If targets are missed

The consequence is reputational and financial rather than regulatory in most jurisdictions, and it surfaces at financing and offtake renewal rather than immediately. Document the baseline, the method and the progress contemporaneously, because retrospective reconstruction is the point at which credibility fails.

Outside the United States

ICMM, IRMA, GHG Protocol and ISO standards apply internationally. MSHA is US federal regulation, and Australia, Canada, Chile and South Africa each operate their own mine safety and environmental regimes.

What Sits Outside an Energy Provider's Scope

• Several of the largest sustainability issues in mining are not energy problems, and treating them as though any single provider addresses everything is how credibility is lost.
• Tailings management is the sector's largest environmental and safety risk. The Global Industry Standard on Tailings Management, or GISTM, was developed following the Brumadinho failure and is now an investor expectation. It covers facility design, monitoring, governance and emergency response, and it requires tailings engineering specialists.
• Water management, including water intensity, closed-loop systems, dry stacking and acid rock drainage, is a process and hydrogeology discipline.
• Mine closure and rehabilitation is regulated and usually financially bonded, requiring closure planning, progressive rehabilitation and long-term monitoring commitments.
• Community and social performance, including consultation, land access and local employment, sits with the operator and specialist advisers.

Why state this plainly

Because an operator reading a sustainability page from an energy provider should know what that provider can and cannot do. The energy and emissions layer is a genuine and substantial part of mining sustainability. It is not the whole of it.

Insurance

Insurers assess tailings management, water risk and closure provisioning alongside operational safety when pricing mining risk. A strong energy decarbonization programme does not offset a weak tailings position.

Health and Safety

• Worker safety is part of sustainable operation, and the technologies reducing emissions frequently reduce exposure at the same time.
• Automation and digital technologies, including remote-controlled equipment, sensors and condition monitoring, reduce human exposure to hazardous environments.
• Electric load-haul-dump machines and underground trucks eliminate diesel particulate matter, which is both an emissions reduction and an occupational exposure reduction. Diesel particulate matter is a recognized carcinogen and a regulated underground exposure.
• Competency frameworks and structured training reduce incidents, and the shift to high-voltage equipment creates a new training requirement rather than removing one.
• ISO 45001 provides the occupational health and safety management framework, and MSHA regulations under 30 CFR govern US mine safety including electrical work.

Where to Start

• Sequence the programme by where the emissions actually are, measured at your own site rather than assumed from sector averages.
• Establish the baseline first, by scope and by source, using the GHG Protocol definitions. Most operators discover the distribution differs from what they assumed.
• Address diesel second, because it is 30 to 80 percent of direct mine-site emissions and haul trucks alone are roughly half. Fuel substitution delivers 40 to 60 percent Scope 1 reduction immediately; trolley assist delivers 30 to 50 percent diesel reduction on assisted hauls; full electrification delivers more and costs more.
• Model the electrical consequence third, before committing to electrification, because the power system has to carry what the fleet stops burning.
• Address Scope 2 fourth unless you run an electricity-intensive process such as aluminium smelting, in which case it moves to first.
• Treat renewable energy certificates as a reporting instrument rather than an operational measure, and do not let them substitute for the first three steps.

What to specify in any proposal

The baseline, by scope and source, with the measurement method. The emissions reduction claimed, with the calculation. The electrical load added, in MW and MWh. The capital and operating cost. The framework the result will be reported against. And who operates whatever is installed.

How Priorities Differ by Mine Type

• The levers are constant. Which one pays first depends on the operation.
• Underground mines gain most from fleet electrification, because the ventilation dividend compounds the direct fuel saving and ventilation is up to 49 percent of mine energy.
• Open pit mines with long steep hauls gain most from trolley assist, which targets the loaded uphill haul where fuel consumption concentrates.
• Remote and off-grid mines must address generation and fleet together, because electrifying onto a diesel microgrid moves emissions rather than removing them.
• Smaller operations face the hardest economics, and research found emissions intensity varying widely across iron and copper mines with higher emitters generally being smaller operations by share of global production. Fuel substitution is usually the only lever that scales down.
• Coal operations face a fundamentally different problem, since fugitive methane accounts for 82 percent of mining-related Scope 1 and 2 emissions and is not addressed by any energy lever on this list.

What Prismecs Does

Prismecs delivers power generation, distributed energy and electrical infrastructure for industrial sites, which is the layer that carries a mine's electrification and renewable integration.

Delivered project scope includes eight TM2500 dual-fuel units totaling 260 MW at Birr, Switzerland, online in six months with a new 220 kV interconnection; four TM2500 units totalling 110 MW at Duqm, Oman, kept grid-ready with resident O&M crews, CMMS and parts support; an LM2500XPRESS plant at Miaoli, Taiwan delivered in ten months; DC-coupled battery energy storage for solar and hybrid applications; and owner's engineering on a 7 MW, 28 MWh battery storage system including the utility interconnection application.

That record is industrial power delivery rather than mining delivery, and it applies directly to the power consequence this article describes: generation capacity, hybrid configuration, storage integration, electrical distribution and the operations that keep them running.

Capability spans distributed energy solutions for site power, microgrids and storage, power generation asset services for the equipment, I&C services for electrical systems, controls and commissioning, O&M services for the operating phase, EPCM services for project delivery, owner's engineering for independent technical review, and technology and consulting for options analysis. Sector context is on the metal and mining page.

One scope boundary worth stating. Prismecs supplies power and electrical infrastructure. Geological assessment, ore body modelling, extraction sequencing, tailings engineering, water management and closure planning are separate disciplines with separate providers, several of them requiring competent persons reporting under JORC or NI 43-101.

Apply this article's criteria to any proposal, including ours. Ask for your emissions baseline by scope and source before accepting any reduction claim. Ask what electrical load the proposal adds, in MW and MWh. Ask whether the generation serving it is lower-carbon than what it replaces. Ask who operates it.

To discuss mine site power, electrification infrastructure or renewable integration, send your site location and grid status, connected and peak load by area, current fleet and fuel consumption, and any electrification plan to sales@prismecs.com or call +1 (888) 774-7632.

Frequently Asked Questions

How much does mining contribute to global greenhouse gas emissions?

The mining and metals sector was responsible for 11 percent of global greenhouse gas emissions in 2024, split 3 percent from mining activities and 8 percent from metal production. That makes it the sixth-largest source globally, behind power generation, transport and agriculture. The figures come from the ICMM's dataset covering 1,700 facilities across 14 commodities, representing 87 percent of global production.

What is the split between Scope 1 and Scope 2 emissions in mining?

Ninety-three percent of sector emissions are Scope 1, generated on site, totalling 5.5 Gt CO2 equivalent. The remaining 7 percent, or 0.4 Gt CO2 equivalent, are Scope 2 from purchased electricity. That 13-to-1 ratio means capital allocation should emphasize on-site operational modification rather than grid-based renewable energy procurement, which runs against the instinct to buy renewable certificates first.

Which commodities account for most mining emissions?

Steel production at 55 percent, coal mining at 23 percent and aluminium production at 15 percent, together accounting for 93 percent of sector Scope 1 and 2 emissions. Fugitive emissions from coal mining alone account for 82 percent of all mining-related Scope 1 and 2 emissions. Non-coal mining contributed only 0.54 percent of global greenhouse gas emissions in 2024.

How much of mine-site emissions come from diesel?

The ICMM puts diesel-powered mining vehicles at 30 to 80 percent of direct emissions at a mine site, depending on site geography and the commodity being mined. Haul truck diesel combustion alone generates roughly 50 percent of all direct mine-site emissions. There are around 28,000 large mine hauling trucks globally, consuming 25 billion litres of diesel and emitting over 69 million tonnes of CO2 as Scope 1.

Which equipment produces the most emissions at a mine?

Haul trucks, by a wide margin. Research into surface mining operations found haul trucks the single biggest source at 35 percent of total mine emissions, with crushers at 20 percent, bulldozers at 7 percent and excavators at 5 percent. The same analysis put Scope 1 from diesel in mobile equipment at 40 to 50 percent of mine CO2 emissions and Scope 2 from non-renewable electricity at 30 to 35 percent.

What does trolley assist save?

Trolley assist systems for haul trucks reduce diesel consumption by 30 to 50 percent. The system feeds electrical power to trucks through an overhead line during the loaded uphill haul, contacted by a pantograph on the truck, targeting the phase where a haul truck burns most of its fuel. It works on fixed routes and does not require the truck to carry a large battery.

Can biofuels reduce mining emissions without replacing the fleet?

Yes. Biofuel adoption can cut Scope 1 emissions by 40 to 60 percent depending on fuel specifications. Hydrotreated vegetable oil, a renewable diesel, runs in most existing compression ignition engines with limited or no modification, making it a transitional measure rather than a capital programme. Most operators sequence fuel substitution now and electrification as fleet replacement cycles arrive.

Why does fleet electrification reduce ventilation energy?

Because ventilation exists partly to dilute and remove diesel particulate matter, carbon monoxide, nitrogen oxides and engine heat. Electric machines produce none of the exhaust and far less heat, so the required airflow falls. Ventilation alone can account for up to 49 percent of a mine's energy consumption, which makes the ventilation reduction a second saving separate from the fuel saved.

Does buying renewable energy certificates reduce mining emissions?

It reduces reported Scope 2 emissions and delivers no physical change at site. Scope 2 is only 7 percent of sector emissions, so a programme achieving 100 percent renewable electricity while leaving the diesel fleet untouched has addressed the smaller share. Treat renewable certificates as a reporting instrument rather than an operational measure, and sequence them after the diesel question.

What renewable fraction can an off-grid mine achieve?

Published off-grid mine projects suggest roughly 20 percent for solar plus storage, and around 50 percent where wind is added. Agnew Gold Mine in Australia runs a 56 MW off-grid system combining solar, wind, diesel or gas and battery at roughly 50 percent renewable fraction. Firm dispatchable generation remains necessary because the load does not stop and solar does.

What happens to the electrical system when a fleet electrifies?

It gains a large new load. The energy formerly delivered by a fuel truck arrives through the substation instead, requiring charging infrastructure sized to the fleet and duty cycle, distribution capacity the network may not have, and generation capacity on off-grid sites. Electrifying onto a diesel microgrid moves emissions rather than removing them, which is why electrification and renewable integration are pursued together.

Which frameworks govern mining sustainability?

The ICMM Mining Principles for member commitments, with members pledged to net zero Scope 1 and 2 by 2050 across over 650 sites. The IRMA Standard for Responsible Mining for third-party assurance. Towards Sustainable Mining, the Mining Association of Canada protocol set. The GHG Protocol for emissions accounting. ISO 14001 for environmental management, ISO 45001 for occupational health and safety, and MSHA under 30 CFR for US mine safety.

What is GISTM and who handles it?

The Global Industry Standard on Tailings Management, developed following the Brumadinho tailings dam failure and now an investor expectation. It covers facility design, monitoring, governance and emergency response. Tailings management is the sector's largest environmental and safety risk and requires tailings engineering specialists. It is not an energy or power infrastructure discipline and should not be procured as one.

Where should an operator start on decarbonization?

Establish the baseline by scope and source using GHG Protocol definitions, because most operators find the distribution differs from sector averages. Address diesel second, since it is 30 to 80 percent of direct emissions. Model the electrical consequence third, before committing to electrification. Address Scope 2 fourth, unless you run an electricity-intensive process such as aluminium smelting, in which case it moves first.