Your Free Guide: Top 5 Most Polluting UK Companies (Excluding energy companies 2025)
Number 1 : Tata Steel UK
Estimated annual emmissions : 6.2m Tonnes (Metric Tonnes of CO2)
Its Port Talbot site has historically been the largest industrial polluter in the UK. Even as they begin the multi-year switch to electric furnaces, the 2025 data still reflects the massive carbon footprint of traditional blast furnace steel production.
Number 2 - British Airways (IAG)
Estimated annual emmissions : 4.0m Tonnes (Metric Tonnes of CO2)
As the UK’s flag carrier, BA’s carbon footprint is massive due to its long-haul flight schedule. Aviation is now the fastest-growing sector of emissions in the UK as other industries clean up.
Number 3 - British Steel
Estimated annual emmissions : 3.3m Tonnes (Metric Tonnes of CO2)
Its Scunthorpe site is home to the last remaining coal-fired blast furnaces in the UK. Even as the company faces a government-led intervention to manage its financial and environmental collapse in 2025, the facility continues to rely on 19th-century coking coal technology that emits more CO_2 than the weight of the steel it produces.
Number 4 - easyJet
Estimated annual emmissions : 3.1m Tonnes (Metric Tonnes of CO2)
Its business model relies on a high volume of short-haul flights that drive up absolute pollution levels. Even with a modern, "efficient" fleet, the company’s rapid growth in 2025 see’s it come in as the 4th highest polluting business in the UK on this list.
Number 5 - Tarmac
Estimated annual emmission : 2.5m Tonnes
As the UK’s leading cement producer, its chemical manufacturing process is inherently carbon-heavy. In 2025, it remains a top polluter because the extreme heat required to make concrete which cannot yet be fully powered by renewable electricity.
For reference: On average a UK citizen used 8.4-10 tonnes of CO2 per year