Scientists said the study warns that the Government must come clean with the public about the high emissions cost of eating meat, while also dramatically improving public transport options.
The study from the ESRI reveals almost half (47pc) of people see no need to cut down on meat, while nearly a third (30pc) have no intention of using their car less and a quarter (25pc) say they cannot do so.
The findings appear contradictory, since studies repeatedly show the majority of the Irish public are very aware of and worried about climate change.
However, Shane Timmons, of the ESRI’s behavioural research unit, said there were “widespread misunderstandings” about what actions mattered most.
“Most people recognise the need to reduce their own carbon footprint and many have already made changes to their daily life,” Dr Timmons said. “But knowing which actions make the biggest difference is a big problem.”
The study required people to keep a food and travel diary for a day and share their usual weekly habits.
Only 4pc of those who took part identified the type of food they ate as a contributor to climate change. That is despite the majority eating lots of red meat, which is the most carbon-intensive food.
People were more likely to believe the distance their food travelled or the packaging it came in had a higher climate impact than the food itself. In fact, food miles and packaging make up only about 18pc of the emissions associated with red meat.
The perceived cost of alternative ingredients was the major deterrent to preparing more meat-free meals, even though the ESRI said the evidence was that it would save people money.
Many also said they did not know what to eat to reduce food-related emissions.
Dr Timmons and his fellow authors said the lack of public awareness about food choices and climate was “unsurprising” because there was no public education on the issue.
“There is no current policy strategy on reducing diet-embedded emissions,” they said. “The only reference to diet in Ireland’s Climate Action Plan is the reduced risk of health conditions like heart disease from reduced meat consumption, with no corresponding action to encourage this shift.”
The Government and public bodies have shied away from calling for reduced meat intake, because it remains national policy to grow beef exports and the agribusiness sector has lobbied fiercely against any hint of a rollback.
The Environmental Protection Agency (EPA) took down social media postings supporting “meat-free Monday” initiatives last year after a farmer backlash.
Reasons the ESRI found for people holding firm to their driving habits were different, with a much smaller proportion (20pc) unaware their car was a big part of their carbon footprint.
Most knew the emissions cost, but many said scarce or unreliable public transport left them with no option but to keep driving. There was a rural-urban divide in how the availability of public transport affected behaviour but there was little difference in how other factors influenced choices.
The higher cost of buying an electric vehicle was cited across the board.
Having a disability or caring for someone with limited mobility was also cited by all groups as a reason a private car was necessary.
“For transport, the findings suggest that awareness raising on the sources of emissions is unlikely to be of further benefit,” the authors said. “The largest gains are more likely to be achieved by increasing the supply and reliability of accessible public transport, particularly outside Dublin.”
Transport emissions are a big concern as they continue to rise, wiping out some of the savings made in areas such as power generation.
The study also revealed misunderstandings about the impact of home energy use. Almost half of those surveyed did not mention it as a significant contributor to their carbon emissions.
Those who did were more likely to say cooking was the biggest issue – when in fact room heating, water heating and using washing machines and tumble driers are all higher emitters.
More than one in 10 people mentioned watching TV as one of the behaviours that mattered most for their carbon footprint, when TVs typically account for just 1pc of daily home energy use.
The EPA funded the research to try to identify what is preventing individual climate action when other studies it has commissioned show levels of awareness and concern are high in Ireland.
Dr Eimear Cotter, of the EPA’s office of evidence and assessment, said: “It is clear from this research that much better information is needed to inform people what actions they can take to make the biggest difference to their carbon footprint.”