Transport now accounts for a third of all carbon dioxide (CO2) emissions in Ireland and levels have not improved in the last five years despite improvements in car technology, a new study has found.
The study, Energy in Transport: Trends and Influencing Factors 2006, produced by Fergal O'Leary, Martin Howley and Dr Brian Ó Gallachóir of Sustainable Energy Ireland (SEI), found that fuel consumption for new petrol cars on the road in 2005 was 7.2 litres per 100km (40mpg), an increase of 1.6 per cent on average consumption in 2000.
This indicates that newly purchased petrol cars are becoming less fuel efficient, the report said.
Presenting the report yesterday, Mr Howley said that though car manufacturers claim that vehicles are more fuel efficient it is not reflected in the figures and there had been no improvement in CO2 emissions in cars coming onto our roads between 2000 and 2005.
"Purchasing trends toward larger cars are offsetting technical improvements," he said.
The study found that the numbers of cars with engine sizes of 1.2 litres or less are declining while larger engines have become more popular. The number with engine sizes above 1.9 litres has almost doubled since 1990.
The report, based partly on figures taken for the first time from NCT centres around the country, found that average car mileage had fallen between 2001 and 2005 by almost 10 per cent.
Mr Howley attributed this to an increase in the numbers of cars on the road, with many households owning two cars. In 2005 there was 507 cars for every 1,000 adults in the State, up from 312 in 1990.
"There is still a potential for growth," he said. "There are 718 driving licence holders per 1,000 adults in the country."
He attributed an upward trend in the age of cars on the road to the 00 effect.
"In the year 2000 there were very high sales in cars; people wanted the 00 registration. As these cars age they are contributing to the increasing age profile since then."
The report also found a 264 per cent increase in fuel consumption by road freight between 1990 and 2005, attributed in part to the high number of construction and road building trucks on the roads.
David Taylor, chief executive of SEI, said that there should be a stronger correlation between car tax and CO2 emissions rather than simply engine size.
"I think the Minister is considering this," he said.
