Galp, the association said in a statement, not only continues to lead the list of the most polluting companies but also increased its emissions by 11%.

Based on European Commission data on emissions registration associated with the European Emissions Trading Scheme (ETS), Zero's ranking of the most polluting entities is mostly composed of the refining, energy, and cement sectors, as well as TAP, which rose to second place on the list (from third last year).

However, overall, there was a reduction in carbon dioxide (CO2) emissions, the main greenhouse gas causing climate change, particularly due to the decline in emissions from fossil-fuelled natural gas power plants, primarily in Tapada do Outeiro but also in Pego, due to the increased share of renewable energy.

The top 10 polluters in the 2024 ranking are thus dominated by Petrogal – Sines Refinery, followed by TAP, Cimpor – Alhandra, and Cimpor – Souselas, in third and fourth place, respectively, and Secil – Outão, in the middle of the table.

In sixth place is Elecgás – Pego Combined Cycle Plant, followed by CMP, cement companies, Fábrica Maceira-Liz, and then in eighth place is EDP – Lares Thermoelectric Plant. Lusical – Mineral Industry – Limestone Calcination – Non-Hydraulic Lime Production – ranks ninth on the list of most polluting plants, and Turbogás, a combined cycle plant in Tapada do Outeiro, ranks 10th.

Compared to 2023, the most significant changes are the significant reductions in emissions from fossil-fueled natural gas thermal plants. Turbogás, Tapada do Outeiro, was second in the previous ranking and is now 10th, and Elecgás (Pego) was fourth and dropped to sixth.

In its data analysis, Zero highlights Petrogal's Sines refinery for dominating the ranking for the fourth consecutive year.

The figure achieved by the refining sector "shows the very significant and growing weight of fossil fuels in our economy and polluting emissions; GALP continues to be a company focused on the exploration and production of fossil fuels, with more than six and a half times its investment dedicated to them compared to its investment in renewables," Zero said in the statement.

Between 2023 and 2024, emissions reached approximately 2.6 million tons of carbon dioxide, an increase of 11% (approximately 270,000 tons), representing almost 5% of Portugal's total net emissions in 2023 (for comparison).

TAP saw a slight increase in emissions, of one percent, but rose to second place due to the 80% drop in emissions from Tapada do Outeiro. Emissions from the three natural gas plants combined fell from 2.7 million tons in 2023 to 1.1 million in 2024.

Counting the total emissions from the 10 most polluting units, there was a reduction in emissions from 9.5 million tons (in 2023) to 8.5 million tons in 2024, a decrease of 11%. The reduction between 2022 and 2023 had been 14%.

According to the list, in addition to increases at the Sines refinery (up 11%) and TAP (up 1%), Cimpor Alhandra increased by 24%, Souselas by 3%, and Secil in Outão by 4%.

The other five all saw their emissions fall. Elecgás (Pego) fell by 47%, CMP Maceira by 1%, EDP by 9%, Lusical by 3%, and Turbogás by 80%.

The CELE (Electronic Energy Consumption) includes the main units in heavily polluting sectors, such as thermal power plants, refining, cement, pulp, and glass, among others. In Portugal, 136 companies declared emissions in 2024 under the CELE (Electronic Energy Consumption).

In the case of thermal power plants using fossil fuels, all emission allowances must be acquired (purchased at auction), while in other sectors, a large portion of the allowances are offered free of charge and the remainder must be purchased.

In the near future, everything indicates that the Sines refinery, fossil-fueled natural gas combined-cycle plants, and the cement sector will continue to dominate the ranking of the largest carbon dioxide-emitting business units, along with growth in the aviation sector.

Zero's analysis is part of the LIFE EFFECT project, funded by the European Commission, which aims to promote broader civil society participation in decision-making and monitoring processes, ensuring that the ETS benefits not only the climate but also people.