Aluminium makers are set to boost low-carbon metal output by 10% in 2023 and churn out even more in the years ahead, driving down the cost for carmakers seeking climate-friendly supplies and shrinking the industry’s hefty carbon footprint. Aluminium is the most energy-intensive metal to produce, accounting for about 1.1 billion tonnes of global carbon dioxide (CO2) emissions per year. Next year’s forecast increase in “green aluminium” output would reduce that by 13-million tonnes, or about 1.2%.