On 12 December 2024, India's Ministry of Steel did something no other government has done: it published a formal, numeric definition of what "green steel" actually means.1 Not a slogan, not a marketing claim, a measurable emissions threshold, with a star rating attached, that any Indian steel plant can be tested against.
A First-of-Its-Kind Definition
India became the first country in the world to define green steel through a formal taxonomy.1 Before this, "green steel" was a term steel producers and buyers used loosely and inconsistently, useful for marketing, not verifiable for procurement. The taxonomy fixes that by defining green steel purely in terms of measured carbon intensity: a steel plant qualifies as producing green steel if its CO2-equivalent emission intensity falls below 2.2 tonnes of CO2e per tonne of finished steel.2
Below that 2.2 threshold, the taxonomy doesn't stop at a single pass/fail line, it grades plants on a star scale, so "green" isn't binary but a spectrum a plant can be rated on and improve within:
| Rating | Emission Intensity |
|---|---|
| ★★★★★ Five-Star | Below 1.6 t-CO2e per tonne of finished steel |
| ★★★★ Four-Star | 1.6 – 2.0 t-CO2e per tonne of finished steel |
| ★★★ Three-Star | 2.0 – 2.2 t-CO2e per tonne of finished steel |
Source: Ministry of Steel green steel taxonomy, via S&P Global.2
Who Verifies the Rating
A threshold is only useful if there's an independent way to check a plant against it. The taxonomy designates the National Institute of Secondary Steel Technology (NISST) as the nodal agency responsible for measurement, reporting and verification (MRV), and for actually issuing the certificates and star ratings plants qualify for.2 By mid-2025, the Ministry had already issued green steel certificates to 25 mills under this framework, plants that had gone through NISST's verification process and come out the other side with a documented rating.3
The line that defines "green"Any Indian steel plant emitting below 2.2 tonnes of CO2-equivalent per tonne of finished steel qualifies for a green steel star rating; the lower the number, the more stars.
Why the Threshold Was Set Where It Was
The 2.2 t-CO2e benchmark isn't arbitrary, it's calibrated against where Indian steelmaking actually sits today and where the government wants it by the mid-2030s. Public targets tied to the taxonomy call for the sector's average carbon intensity to fall to around 2 tonnes of CO2 per tonne of steel by 2035, bringing India roughly in line with global averages.4 Framed that way, the taxonomy isn't just a labelling exercise, it's a transition tool. Plants that qualify today, even at the three-star tier, are already operating close to the level the entire national industry is being asked to reach within a decade.
There's also a trade dimension driving urgency here. The European Union's Carbon Border Adjustment Mechanism (CBAM) will start pricing carbon on imported steel, meaning Indian exporters increasingly need a credible, third-party-verified emissions number to hand to European buyers, not a claim, a certificate. India's taxonomy and NISST's verification process exist in part to give exporters exactly that.1
Backward-integrated producers, running their own DRI, captive power and rolling in one chain rather than buying inputs from a fragmented supply chain, are structurally well placed to track and lower this number, because every stage of the emissions footprint sits inside one company's own operational data rather than scattered across suppliers.