Irish airlines release as much greenhouse gas into the atmosphere as Irish livestock, according to the latest figures published by the European Commission.

Nine Irish-based aviation companies reported a combined 12.4m tonnes of carbon dioxide (CO2) emissions in 2018 under the EU emissions trading scheme (ETS) – the European climate quota system for companies using large quantities of coal, oil or gas.

Meanwhile, all the methane belched by Irish cattle and sheep in 2017 was equivalent to 11.5mtCO2, according to the EPA. This goes up to 13.5mtCO2e if greenhouse gases from manure management is included.

Ryanair alone generated 9.8mtCO2, the highest figure for any company in the country. The ESB's coal-fired Moneypoint power station released 2mtCO2, with many more electricity generators also among the top emitters.

Some aluminium and cement factories emitted over 1mtCO2 each.

Food processing

Food processing factories in the EU-ETS accounted for a combined 800,000tCO2, with four milk processing plants at the top of the list. Glanbia in Ballyragget and Kerry in Listowel each released more than 81,000tCO2 in the atmosphere last year, followed by Lakeland in Bailieborough and Dairygold in Mitchelswtown.

In total, milk processors accounted for three quarters of the greenhouse gases released by food processors in the EU-ETS. The weight of dairy processing relates to the large quantities of heat required for milk processing, especially in driers.

Diageo's St James's Gate brewery in Dublin comes fifth with over 51,000tCO2, and Midleton distilleries also had significant emissions over 41,000tCO2.

Irish Distillers, which runs the Midleton Distillery, plans to cut its emissions by 30% between now and 2030 while growing production by 5% each year, the company's environmental and energy manager James Brown told the SEAI Energy Show last week.

Other high-energy users such as meat factories do not feature on this list, because they mostly use electricity for needs such as chilling. In this case, the stations generating their power are the ones burning the fuel and reporting the emissions.

Only those factories with adjoining rendering plants, such as ABP in Waterford and Cahir, have large fuel uses and fall under the emissions trading scheme.

Pharmaceutical companies, hospitals and data centres were also among the large emitters reporting under the EU-ETS.