The most consequential update in the latest LME Insight sustainable premiums methodology is the tightening of carbon thresholds. In the revised framework, eligibility is the first test; premiums come later. Eligibility depends on verified producer disclosures submitted through LMEpassport, supported by independent assurance. If no disclosure is provided, no qualification is granted.
Key changes: aluminium and copper
The aluminium carbon threshold has moved to 8 from 10 tCO₂e/t, while copper has moved to 4 from 5 tCO₂e/t.
Aluminium’s revision is a consequence of blunt feedback: 10 was too high. It did not sufficiently separate lower carbon aluminium from business as usual. At 8, the threshold excludes much of the higher emitting smelting base and puts the focus where it belongs: smelter-level performance, renewable supply, and genuinely cleaner production. It is still a balancing act, and ambition must meet liquidity, but the standard for what qualifies as truly sustainable aluminium is now clearer.
The previous copper number sat around the global average for LME brands, offering little real distinction. Four is tougher. This is the threshold doing its job: providing differentiation, not symbolism. Signalling a true distinction to a market that is willing to pay a premium for a more sustainable metal.
Thresholds are gates, not price setters
These limits do not set the premium. They decide which metal can qualify for inclusion, while premium price discovery remains transaction-led. The LME is working to fine-tune carbon threshold glide paths, and details of this will be shared in the future as the product evolves. LME will further calibrate thresholds as liquidity and data improve.
Data capture also widens
Alongside the threshold changes, LME Insight is opening transaction sourcing.
The methodology no longer leans on a single source. Executed trades can come from approved spot trading platforms or be reported directly to LME Insight, including qualifying long-term contract transactions.
That shift was heavily signalled in feedback, and it brings the assessment closer to how the market trades.
The takeaway
These changes signal a more serious line in the sand. Lower carbon eligibility is tighter, clearer, and what the market is looking for.
