Between 1990 and 2023, Transport shows the greatest overall increase of GHG emissions at 129.4%, from 5,143.3 kt CO₂eq in 1990 to 11,797.6 kt CO₂eq in 2023, with road transport increasing by 133.9%. Fuel combustion emissions from Transport accounted for 9.2% and 21.5% of total national greenhouse gas emissions in 1990 and 2023, respectively. The increase in emissions up to 2007 can be attributed to general economic prosperity and increasing population, with a high reliance on private car travel as well as rapidly increasing road freight transport. Over the time series passenger car numbers increased by 191% and commercial vehicles increased by 177%. Both the increase in transport emissions up to 2007 and the subsequent fall during the financial crisis highlight that transport emissions have not yet been effectively decoupled from economic activity through sustainable planning or electrification.
This sector accounts for emissions from the combustion of fuel for all transport activity including aviation, road, railway, water-borne navigation and other transportation (which includes gas pipeline transportation). In 2023, Transport emissions increased slightly by 0.3% (or 0.04 Mt CO₂eq) on 2022 and, at 11.8 Mt CO2eq, and represent 21.5% of national total emissions.
Emissions from road transport were relatively stable for the period 2015-2019, at an average 11.6 Mt CO₂eq but reduced to 9.8 Mt CO₂eq in 2020. However, with the easing and ending of travel restrictions in 2021 and 2022, road transport emissions rebounded to 10.4 Mt CO2eq and 11.1 Mt CO₂eq respectively.
Total energy consumption in road transport increased by 2.4% in 2023; petrol +6.5%, diesel -1.0%, bioethanol +41.0% and biodiesel +29.5%.
At the end of 2023, there were just under 58,000 battery electric (BEVs) and almost 47,000 plug-in hybrid electric (PHEVs) vehicles in Ireland, approximately 53% of the Climate Action Plan target for 2025 of 195,400 or 11% of the 2030 policy target of 944,600 vehicles. As a result, the continued uptake of electric vehicles has meant the annual target in 2023 was exceeded.
(Latest update May 2025)
Under the With Existing Measures scenario, transport emissions are projected to decrease by 8.7% over the period 2018 to 2030 to 11.2 Mt CO2eq.
Emissions are projected to decrease by 20.9% over the period 2018 to 2030 to 9.7 Mt CO2eq under the With Additional Measures scenario (shown as the line in the graph below), which assumes 640,000 electric vehicles will be on the road by 2030, biofuel blends for petrol (10%) and diesel (20%) by 2030 and a reduction in total vehicle kilometres to be achieved by behavioural and sustainable transport measures by 2030.