Carbon Footprint of Steel Per kg & lb (Calculator & Full List of Steel Items)

Steel production requires massive amounts of energy, but have you ever asked what is the carbon footprint of steel?

Because of the high temperatures required to convert iron ore into the steel, the carbon emissions can seem excessive. But, there’s something wonderful about the steel industry that you might not know.

Steel can be recycled…and it’s cost effective for companies to do and use in new products. Therefore, many products created from steel use recycled material.

It really all comes down to whether a blast furnace or an electric arc furnace is used to fabricate steel, because the emissions generated by these two methods are widely different.

Although the number of items made from steel is enormous, this complete guide outlines the carbon footprint of steel for the most common products, and explains how to calculate that emissions amount based on the process used.

Carbon Footprint of Building Materials: Carbon Footprint of Steel

Steel, which forms part of construction and building materials, also contributes to the overall carbon footprint of building materials.²⁰

It is estimated that the CO₂ emitted from manufacturing cement, rubber, steel, and other construction materials, make up around 60% of a structure’s total CO₂ emissions.

You can calculate the emissions for your construction project here.

Some addition facts include:

• 3.5 billion tons of cement are produced annually, emitting 2.8 billion tons of CO₂.
• For every pound of cement manufactured, at least 0.9 pounds of CO₂ is released.
• Timber manufacturing and wood used in construction aid in cutting CO₂ emissions. Whereas a residential home containing a steel frame emits an estimated 2.9 tons of carbon, a timber-framed house stores an estimated 7.5 tons of CO₂.
• 1.8 tons of CO₂ is removed from the atmosphere with every dry ton of timber manufactured.
• 90% of rubber is manufactured in Asia and together with steel, timber, concrete, and other materials, the global carbon footprint of building materials is almost 20% of all CO₂ emissions.¹
• The building industry as a whole is responsible for almost 50% of global CO₂ emissions (including 27% CO₂ emissions from building operations)
• Three types of building materials in particular are responsible for 23% of worldwide CO₂ emissions (these materials are mainly used in the building industry).²

Industry	Percentage of CO2 Emissions	Detailed Breakdown
Transport industry	CO2 emitted – 16.2%	Road – 11.9% Aviation – 1.9% Rail – 0.4% Pipeline – 0.3% Ship – 1.7%
Building industry	CO2 emitted – 17.5%	Residential – 10.9% Commercial – 6.6%
Energy (Industrial)	CO2 emitted – 24.2%	Iron and Steel – 7.2% Non-ferrous metals – 0.7% Machinery – 0.5% Food and Tobacco – 1.0% Paper/Pulp/Printing – 0.6% Chemical and petrochemical energy – 3.6% Other – 10.6%
Agriculture / Fishing Industry	CO2 emitted – 1.7%	No Data
Fuel combustion (unallocated)	CO2 emitted – 7.8%	No Data
Energy production (fugitive emissions)	CO2 emitted – 5.8%	Coal – 1.9% Oil and Natural Gas – 3.9%
	The total amount of CO2 emitted – 73.2%

Relate: Sustainable Architecture: Living Buildings with Carbon Offsets

What Is the Carbon Footprint Per Material?

Different materials generate different amounts of emissions, both embodied and direct.

Embodied emissions are measured from the process required to make a material ready for use. For example, steel is made using mined ore that is transformed one of two ways (explained below), either a blast furnace or electric arc.

The embodied emissions from steel are measured from the mining process (the energy required to mine and ship the ore). But, they also include the energy required to transform the ore into usable steel slabs, billets and blooms.

• Rammed Earth: 48kg embodied CO₂ per m³
• Timber (softwood): 110kg embodied CO₂ per m³
• Timber (cross-laminated): 219kg embodied CO₂ per m³
• Stone: 237kg embodied CO₂ per m³
• Clay Brick: 345kg embodied CO₂ per m³
• Reinforced Concrete: 635kg embodied CO₂ per m³
• Glass: 3,600kg embodied CO₂ per m³
• Steel: 12,090kg embodied CO₂ per m³
• Aluminum: 18,009kg embodied CO₂ per m³

Carbon Footprint of Metals

The carbon footprint of metal mining and processing of different types of metals require energy-intensive processes, which in turn causes the industry to emit 10% of global carbon emissions.²¹

Steel production accounts for 7% of metal mining and related CO₂ emissions every year.

Nickel, cobalt, and dysprosium processing emit the highest amount of CO₂, and the demand for these metals is estimated to increase exponentially by 2050.³

The below chart indicates the percentage that the carbon footprint of steel makes up compared to other subsectors.⁴

Metal	Demand by 2030	Demand by 2050
Aluminum	15 – 22Mt	25 – 42Mt
Copper	5.5 – 8Mt	9 – 15Mt
Zinc	0.7 – 1.5Mt	1.5 – 2.7Mt
Lithium	1.900 – 3.000kt	3.700 – 8.000kt
Nickel	1,000 – 1.800kt	1.800 – 4.000kt
Silicon	650 – 1.250kt	1.000 – 1.700kt
Cobalt	130 – 210kt	270 – 600kt
Neodymium	65 – 75kt	140 – 170kt
Praseodymium	20 – 22kt	45 – 55kt
Dysprosium	2.3 – 4kt	3.5 – 7kt

Carbon Footprint of Steel

The carbon footprint of steel is near twice the production amount. This means that 1.85 tons of CO₂ are emitted for each ton of steel produced which is equal to the total global emissions of Japan on an annual basis.

In 2018, the global steel industry was responsible for 3.3 billion tons of carbon emissions.

Stainless Steel Carbon Footprint

To determine the stainless steel carbon footprint, the following factors must be considered:

1. Scope 1 Emissions: this is related to direct emissions that can be controlled by companies.
2. Scope 2 Emissions: this is related to indirect emissions such as bought electricity, and other forms of energy consumption.
3. Scope 3 Emissions: this is related to the extraction, processing, and transport of metals, including the energy required for all these processes.

Furthermore, stainless steel is fully recyclable, and up to 85% of stainless steel is recycled.²²

The following table indicates the lifecycle of stainless steel in sectors where it is commonly applied and used.⁵

Sector (End of Life)	Lifespan (in Years)	Landfill	Collected and Recycled
			Total	As Stainless Steel	As Carbon Steel
Building and Infrastructure Sector	50	8%	92%	95%	5%
Transport Sector (passenger cars)	14	13%	87%	85%	15%
Transport Sector (other vehicles)	14	13%	87%	85%	15%
Industrial Machinery Sector	25	8%	95%	95%	5%
Appliances and Electronic Sector (household)	15	30%	70%	95%	5%
Metal Products Sector	15	40%	60%	80%	20%

Carbon Footprint of Steel Per Kg

The emissions factor when calculating the carbon footprint of steel per kg is:

• Iron metal (steel) 1kg = 1.77CO₂eq
• Stainless steel 1kg = 6.15CO₂eq
• Recycled steel 1kg = 0.88CO₂eq
• Virgin steel 1kg = 3.29CO₂eq

How Much CO2 Is Produced Per Ton of Stainless Steel?

The next question to answer is, how much CO₂ is produced per ton of stainless steel?

The average CO₂ emissions per ton of stainless steel are 0.39 tons.

The below table indicates the total CO₂ emissions per ton of stainless steel:⁶

Total CO2 Emissions (1 ton CO2 / 1 ton stainless steel)
Scrap (85%)	2.13
Scrap (75%)	2.47
Scrap (50%)	3.33
Scrap (30%)	6.87

How Much CO2 Is Produced Per Ton of Steel?

Another common question asked about steel production, is how much CO₂ is produced per ton of steel.

The average CO₂ emissions per ton of steel are 1.5 to 3 tons, depending on how the steel is produced.

Carbon Footprint of Stainless Steel Water Bottle

Stainless steel water bottles are some of the most popular stainless steel products used around the world.

Unfortunately, the carbon footprint of stainless steel water bottles is far higher than the carbon footprint of a single plastic bottle.

The manufacturing of a 300-gram stainless steel bottle requires the following:

• 7x the fossil fuel of the manufacturing process of a plastic water bottle

• Extraction of hundreds of times more resources (metal)

In addition to this, producing a single stainless steel bottle produces at least 14x more CO₂ emissions than the production process of one plastic water bottle.²³

However, if a stainless steel water bottle is used in place of 50 plastic water bottles and is used at least 500 times, it is more beneficial for the climate than plastic water bottles.⁷

Environmental Impact of Steel Production

The total environmental impact of steel production is as follows:³³

• More than 240 kilograms of steel are manufactured for every person in the world, every year.
• This equals 1800 million tons.

To put this into perspective, the following comparison applies:

Furthermore, the environmental impact of steel production includes the mining of iron ore.

Iron ore is the main component of steel production, and of the 2,000 million tons mined every year, around 95% is directed to and used by the steel sector.

Iron ore is the third most processed and produced commodity in the world (by volume), and the second most traded commodity.

The process of mining iron ore consumes vast amounts of energy and releases pollution such as CO₂, nitrous oxide, sulfur dioxide, and carbon monoxide.

The environmental impact of steel production doesn’t end there, as iron ore mining also causes water pollution, with acid drainage that continues for millennia after all mining activities have ceased.

Additionally, producing steel from mined iron ore happens to be the most energy-heavy and highest carbon emissions-producing process in the world.

Global steel production has risen sharply since 1950, contributing to excessive CO₂ emissions:

• 1950: 189 million tons of steel produced
• 1975: 644 million tons of steel produced
• 2000: 850 million tons of steel produced
• 2018: 1808 million tons of steel produced

By 2018, the following countries were responsible for the highest CO₂ emissions during steel production:

• China: 928.3 million tons of steel produced
•  India: 106.5 million tons of steel produced
• Japan: 104.3 million tons of steel produced
• US: 86.6 million tons of steel produced
• South Korea: 72.5 million tons of steel produced
• Russia: 71.7 million tons of steel produced⁸

Social Impact of Steel Industry

While considering the environmental impact of the steel industry, the social impact of steel industry cannot be ignored.

While CO₂ emissions increase along with an increased demand for steel and steel products, the steel industry continues to support thousands of jobs and strengthens global economies.²⁴

Furthermore, the steel sector is a vital component of the development of a sustainable society.

In Sweden alone, the steel sector supports 26,000 jobs and is essential in generating tax revenues. The export earnings of the steel sector in the country contribute directly to GNP and tax revenues are used to fund public service projects.⁹

Structural Steel Environmental Impact

Structural steel is popularly used for aesthetic purposes and is a firm favorite because of its versatility and longevity.

The structural steel environmental impact is highlighted above.¹⁰

Related Reading: What is a Carbon Footprint Explained in 60 Seconds with Images

Carbon Footprint of Steel

When discussing the carbon footprint of steel, different types of steel should be considered, including virgin and recycled steel.

The carbon impacts of steel (BOF vs EAF) is indicated as follows:

BOF (Basic Oxygen Furnace) Components:

• Iron ore
• Limestone
• 25% recycled steel content
• 71% Global steel production

EAF (Electric ARC Furnace) Components:

• 97% recycled steel
• 3% other elements

Electric Arc Furnace CO2 Emissions

Electric arc furnace CO₂ emissions are almost half the amount produced by basic oxygen furnaces.

The amount of CO₂ emissions is reduced further when the source of energy is renewable.

Virgin Steel vs Recycled Steel

When it comes to the debate of virgin steel vs recycled steel, recycled steel wins hands down.

The embodied carbon footprint of virgin steel is estimated to be five times higher than recycled steel.

Furthermore, EAFs use at least 93% recycled steel, whereas BOFs only use an estimated 25% recycled content.

For the benefit of the environment, it is best to choose high-recycled content instead of virgin steel.²⁵

The following guidelines further indicate CO₂ reductions when implemented properly:

• Utilize shapes that are made using electric arc furnaces
• Utilize only reclaimed or recycled structural steel
• Choose braced frames over moment-resisting frames
• Choose joists over rolled shapes
• Size steel members correctly to avoid waste
• Utilize high-grade steel
• Design with adaptation and deconstruction in mind
• Reinforce only when absolutely necessary
• Use fabricators to increase efficiency
• Buy local¹¹

Recycled Steel in Construction

There are a vast number of reasons to use recycled steel in construction projects. These include:¹²

Steel rules the construction market	100% recyclable Retains strength even when recycled Most recycled material on Earth
All steel products contain recycled steel	Cars, ships, bridges, trains, buildings, etc. The US has been recycling steel for more than 150 years Recycled steel is an unmissable part of creating new steel Steel is easily separated from other waste, making the recycling process economical
The US steel consumption alone is around 70 million tons a year	81 million net tons of new steel products were shipped by steel mills in 2020 alone More steel is recycled in the US than plastic, aluminum, glass, and paper combined
Recycling steel is an energy saver	Far less energy is required to melt end-of-lifecycle steel than to create virgin steel Every ton of recycled steel saves at least 642 kW hours The process of recycling steel saves enough electricity to power at least 18 million houses for a year Because of continuous improvements in the steel sector, it takes 34% less energy today to produce steel than it did fifty years ago
Steel recycling saves resources	A single ton of recycled steel conserves 2,500 lbs of iron ore, 1,400 lbs of coal, and 120 lbs of limestone Continuous steel recycling prevents overcrowded landfills One ton of recycled steel saves 250 cubic feet (of space inside a landfill) Steel mills already reuse 95% of the water used during steel processing Air and water CO2 emissions have already been cut by 90% Using steel in the place of wood, protects forests around the world
New steel facts (modern steel)	Modern steel is at least 30% stronger than steel produced ten years ago If the Golden Gate bridge had to be built in modern times, it would take half the original amount of steel used To that end, structural steel contains at least 77% recycled content

Carbon Footprint Calculator for Steel Production

Calculating carbon emissions related to steel production is made easy with the use of a carbon footprint calculator for steel production.²⁶

This calculator requires the following inputs:

Efos (fossil fuel combustion) + Eflu (flux consumption and carbonaceous consumption during production) – Eseq (partial carbon sequestration products) = ECO₂

ECO₂ is the total amount of CO₂ emissions per unit (kg). Eflu is CO₂ emissions produced by the consumption of CO₂ consisting of substances and flux per unit (product in kg), and Eseq is the CO₂ emissions of carbon sequestration per kg unit (product).

The main CO₂ emission factor used for CO₂ calculator is as follows:¹³

Relevant Project	Unit	Emission factor
Fossil Fuel Project	Cleaned coal (kgCO2/kg) Coke (kgCO2/kg) BFG (kgCO2/m3) LDG (kgCO2/m3) Dolomite(kgCO2/kg)	2.456 3.043 0.623 1.283 0.477
Fluxs and Carbonaceous Project	Limestone (kgCO2/kg) Scrap steel (kgCO2/kg)	0.44 0.036
Carbon Sequestration Production Project	Iron production (kgCO2/kg) Steel production (kgCO2/kg)	0.147 0.036

Iron Ore Carbon Footprint

The iron ore carbon footprint is as follows:²⁷

34 million tons of CO₂ of Scope 1 and 2 CO₂ equivalents, and an extra 62 million tons of CO₂ emissions related to land and sea freight.

Environmental Impact of Iron Production

The environmental impact of iron production (iron ore) is vast:

Impact	Main Factors
Air Quality	Major emissions such as CO2, carbon monoxide, nitrous oxide, and sulfur dioxide. The main cause of combustion-related emissions is diesel generators and road traffic (onsite). Industrial pollution directly affects wildlife mortality.
Acid Rock Drainage	When water and oxygen react with sulfur-based minerals and chemicals, acid is produced. Sulphuric acid is commonly created during mining activities and causes major environmental health hazards.
Megafauna	Large mammals including wolves and bears are extremely sensitive to the noise decibels caused by iron ore production.
Quality of Water	Large sources of water are polluted by iron ore mining emissions. Acid water often lands in the ocean.
Safety	Old, abandoned mining sites pose a safety risk, because of hidden entrances and ground sinking.

Greenhouse Gas Emissions From Iron and Steel Production

Greenhouse gas emissions from iron and steel production relate to steelmaking technology that is primarily in use in steel mills and scrap mills.²⁸ These types of mills are responsible for 90% of global steel production:

• 60% via steel mills
• 30% via scrap mills

Production	CO2e (tons per ton product)
Steel Mill (integrated)	1.6 – 2.2
Mini Mill (scrap production)	0.6 – 0.9
Mini Mill (scrap substitutes)	1.4 – 2.0

Projections have been made for the future of GHG emissions in the steel production industry. The below factors consider an estimated 30% growth in steel and iron production:

• Frozen Technology – assuming that the iron and steel industry’s energy efficiency levels and CO₂ factors are fixed at previous levels for each region (1985 – 1995) and ignoring modern industry trends.
• Moderate Change – based on an existing scenario that states that energy efficiency methods are accepted within Europe.
• Accelerated Change – based on the accelerated implementation of energy efficiency methods throughout developed countries and regions, as well as the implementation of emerging techniques (production) in Russia, and China.
• Wonderful World – based on rapid implementation of energy efficiency methods in developing countries to match efficiency methods in Western countries.¹⁴

Related Reading: The Average Carbon Footprint Per Person Is Rising Fast: Is It Too Late? (10 Ways to Help Now)

How To Reduce Pollution Caused By Iron and Steel Industry

When considering how to reduce pollution caused by iron and steel industry, the following factors must be included in the discussion:

• Air pollution control²⁹
• Water pollution control
• Transport pollution control

The following ‘green practices’ are instrumental in reducing the pollution footprint and CO₂ footprint caused by the iron and steel industry:

• Sustainable frame construction (light steel): less time on site = reduced emissions.
• Steel packaging (products): more usage per product = fewer emissions.
• Making use of slag to protect marine life (steel byproduct): slag use = conserved marine environment.¹⁵

Global CO2 Emissions From Steel Production

Global CO₂ emissions from steel production stand at 8%. CO₂ emissions emitted during coal-based steel manufacturing is 1.5 – 3 tons of CO₂ per single ton of steel.

Carbon Capture and Storage Steel Industry

Carbon capture and storage steel industry factors include:

• CCUS Technology (Carbon, Capture, Utilization, and Storage):³⁰ The US government allowed the expansion of the 45Q tax credit in 2018 to increase carbon capture and storage.
• Net Zero Objectives: Capture technologies are increasing the forward move towards net zero objectives.
• Financial Risk Applies: However, tax credits and subsidies mitigate much of this risk.
• Steel Industry Participation: The steel industry can get involved by harnessing raw, and capturing CO₂ to create building materials.¹⁶

Environmentally Friendly Steel Production

Environmentally friendly steel production, which is steel production minus the use of fossil fuels, is one of the methods scientists believe will assist the steel industry in reaching 50% reduced emissions by 2050.

Hydrogen Steel Production

Green hydrogen steel production might only be one of the solutions presented to reach the 50% fewer emissions goal, but considering that heated hydrogen emits water, it is a particularly good way to start.

Also, when hydrogen is produced using just water (by means of electrolysis) and renewable energy sources, the hydrogen is free of CO₂.

The following is required to reach the reduced emissions goal by 2050:

• Current: Grey Hydrogen (natural gas converted to hydrogen)
• 2030: Blue Hydrogen (natural gas converted to hydrogen, while storing CO₂ underground)
• 2050: Green Hydrogen (renewable energy and water converted to hydrogen, releasing only water in the process)^{17, 31}

Carbon Neutral Steel

Carbon-neutral steel became a reality in 2021 when Sweden, in a world first, delivered a shipment of manufactured steel without the use of any fossil fuels.

Industrial quantities of carbon-neutral steel will be available by 2026.

HYBRIT Steel

HYBRIT technology plays a massive role in producing carbon-neutral steel or HYBRIT steel.

HYBRIT (hydrogen breakthrough ironmaking technology) replaces fossil fuels during the production of iron pellets, and during the removal of oxygen by effectively replacing CO₂ and coke with green hydrogen.

Green Steel

Green steel is truly the way of the future, by incorporating technologies such as HYBRIT.³²

It has been estimated that HYBRIT technologies will not only ensure ‘green steel’ but will reduce the entire country of Sweden’s total CO₂ emissions by around 10%¹⁸

World Steel Association CO2 Emissions

The updated version of the World Steel Association CO₂ emissions list is as follows:¹⁹

Performance (Environmental)	Unit (Various)	2018	2019	2020
CO2 Emissions	Tons CO2/ton crude steel cast	1.81 CO2 ton	1.85 CO2 ton	1.89 CO2 ton
Energy Intensity	GJ/ton crude steel cast	19.51 GJ ton	20.06 GJ ton	20.62 GJ ton
Material Efficiency	% of materials converted to products & co-products	96.33%	96.49%	97.86%
Environmental Management Systems (EMS)	% of employees & contractors working in EMS-registered production facilities	97.07%	97.16%	96.11%

Related Reading: Co₂ Emissions of the United States

When considering the above-mentioned measures implemented to ensure 50% fewer carbon emissions by 2050, it is clear that the carbon footprint of steel is on a downward trend for the good of the environment.

Frequently Asked Questions About Carbon Footprint of Steel