Between 1990 and 2021, Transport shows the greatest overall increase of GHG emissions at 112.2%, from 5,143.5 kt CO2eq in 1990 to 10,915.6 kt CO2eq in 2021, with road transport increasing by 115.2%. Fuel combustion emissions from Transport accounted for 9.3 per cent and 17.7 per cent of total national greenhouse gas emissions in 1990 and 2021, 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 178% and commercial vehicles increased by 167%. 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. 

Note: These pages present provisional 1990-2021 Inventory data using global warming potentials (GWP) from the IPCC's 5th Assessment Report (AR5) (updated July 2022) and the EPA's latest 2021-2030 projections estimates (updated June 2022) using global warming potentials (GWP) from the IPCC's 4th Assessment Report (AR4). 

In 2021 the transport sector was responsible for 17.7% of Ireland's greenhouse gas emissions 



Current trends

  • Transport’s Greenhouse gas (GHG) emissions increased by 6.1% in 2021 
  • Road transport which accounts for 94% of all transport emissions rebounded in 2021 by 6.3% (10.3 Mt CO2eq)  
  • Electric vehicles numbers nearly doubled in 2021 compared to 2020, approximately 47,000 currently on Irish roads 


  • Covid restrictions have predominantly influenced the emissions of transport over 2020/21 
  • Increased uptake of electric vehicles may be partly due to fuel price increases 
  • Passenger cars were responsible for approximately 54% of road transport emissions in 2020


  • Significant challenges remain within the transport sector, given that population and the overall transport fleet is projected to grow. Trends indicate that emissions from this sector are still strongly coupled with economic activity 

Transport sector

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). The provisional GHG inventory figures indicate an increase in the sector of 6.1% in 2021 or 0.626 Mt CO₂eq compared to 2020 emissions.  

Emissions from road transport were relatively stable for the period 2015-2019, at an average 11.6 Mt CO2eq but reduced to 9.7 Mt CO2eq in 2020. The expected increase in road transport activity in 2021 has seen emissions rise to 10.3 Mt CO2eq, still below pre-pandemic levels. Total energy consumption in road transport increased by 6.3% in 2021; petrol, +6.1%, diesel +6.7%, bioethanol +4.6% and biodiesel +1.9%. 

Transport emissions in 2021 were 24.5% below peak levels in 2007 primarily due to the effect of some continued COVID restrictions, economic downturn and also due to improving vehicle fuel efficiency, the increased use of biofuels and a significant decrease in fuel tourism in recent years.  

At the end of 2021, there were just under 47,000 battery electric (BEVs) and plug-in hybrid electric (PHEVs) vehicles in Ireland, approximately 24% (compared to 14% in 2020) of the 2025 policy target of 195,300 or <5% of the 2030 policy target of 945,000 vehicles. 

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Projected emissions

Under the With Existing Measures scenario, transport emissions are projected to increase by 0.6% over the period 2020 to 2030 to 10.4 Mt CO2 eq.

Emissions are projected to decrease by 28.0% over the period 2020 to 2030 to 7.4 Mt CO2 eq  under the With Additional Measures scenario (shown as the line in the graph below), which assumes 944,600 electric vehicles will be on the road by 2030 and a biofuel blend for petrol (10%) and diesel (20%) by 2030.