Between 1990 and 2019, emissions from transport showed the greatest overall increase, at 137%, with road transport increasing 142.6%. Transport emissions have decreased by 16.2% below peak levels in 2007, primarily because of the economic downturn, improving vehicle fuel efficiency as a result of changes to the vehicle registration tax, the increase in use of biofuels and significant decreases in fuel tourism in recent years. However, more recently, increases in transport emissions have been recorded for 5 out of the last 7 years (2003-2019) as the economy has grown and transport movements have increased.
In 2019 the transport sector was responsible for 20.4% of Ireland's greenhouse gas emissions
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 pipeline transportation). The final GHG inventory figures estimated transport emissions decreased by 0.3% in 2019 or 0.04 Mt CO2eq compared to 2018 emissions. In road transport in 2019, petrol use decreased by 5.8% while diesel use increased by 0.8% and biofuels use increased by 22%. Looking at the underlying causes, the number of passenger diesel cars increased by 7.1% in 2019 while the number of passenger petrol cars decreased by 1.9%, commercial vehicle numbers increased by 3.2% and employment grew by 3.5% between Q4 2018 and Q4 2019.
Between 1990 and 2019, the transport sector showed the greatest overall increase at 137.0%, with road transport increasing by 142.6%. Emissions decreased by 0.6% in 2019, this can be attributed to an increase in the efficiency of the road transport fleet. Transport emissions decreased by 16.2% below peak levels in 2007. This was primarily due to the economic downturn, improving vehicle standards due to the changes in vehicle registration tax, the increase in use of biofuels and significant decreases in fuel tourism in recent years. The increase up to 2007 can be attributed to general economic prosperity, increasing population with a high reliance on private car travel as well as rapidly increasing road freight transport.
Under the With Existing Measures (WEM) scenario, transport emissions are projected to increase by 10.2% over the period 2020-2030 to 11.6 Mt CO2 eq
Emissions are projected to decrease by 13.4% over the period 2020 to 2030 to 9.1 Mt CO2 eq under the With Additional Measures scenario (shown as the line in the graph below), which assumes 936,000 electric vehicles will be on the road by 2030.