Decarbonising the carbon emissions from flights at Dublin Airport would demand far more land and electricity than many might expect, according to recent analysis. The study highlights the scale of the challenge, showing that fully replacing fossil jet fuel with low-carbon alternatives or offsetting emissions could require land greater than the size of County Tipperary or electricity exceeding current national demand.
Aviation is one of the hardest sectors to decarbonise. Unlike road transport or electricity generation, there are no commercially mature alternatives to fossil jet fuel at scale. In Ireland, air travel is growing rapidly, with residents flying almost twice as much per capita as the European average. In 2024, aviation accounted for six percent of the country’s total greenhouse gas emissions, or around 3.3 million tonnes, roughly half the emissions from electricity generation. Dublin Airport alone contributes about 85 percent of this figure.
The airport’s planned increase in passenger numbers is expected to raise emissions by 22 percent by 2031, equivalent to the emissions from heating 250,000 Irish homes. Reducing flying remains the most direct way to cut emissions, but political and social sensitivities make this difficult.
Technological pathways for decarbonisation fall into two main approaches: replacing jet fuel with low-carbon alternatives or continuing fossil fuel use while removing carbon from the atmosphere.
Sustainable aviation fuels (SAF) offer the most immediate replacement option. Bio-SAF, produced from crops like rapeseed and willow, could cut emissions by up to 80 percent. However, producing enough fuel domestically would require between 0.4 and 1 million hectares of land, or nine to 21 percent of Ireland’s agricultural land. Waste-based fuels and imported blends could contribute only minimally.
Synthetic fuels, created by combining green hydrogen and captured carbon dioxide, avoid land pressures but are extremely energy intensive. Replacing all jet kerosene with e-fuels would demand roughly 42 TWh of electricity, about 15 percent more than Ireland’s total electricity consumption in 2024. Meeting this with onshore wind or solar would require vast areas, or alternatively around 9 GW of offshore wind capacity, roughly ten times the scale of planned first-generation offshore farms.
Offsets using direct air capture or tree planting also face limitations. Capturing emissions from Dublin Airport alone would require multiple large DAC plants or planting up to 1.6 million hectares of forest, equivalent to a third of Ireland’s agricultural land. Afforestation is slow, vulnerable to storms, fires, and disease, and relies on careful long-term management. Critics argue that offsets risk justifying continued fossil fuel use rather than addressing emissions at source.
The analysis illustrates that decarbonising flights is a monumental task. Scientists emphasise that technological fixes or offsets alone will not be enough without broader changes in aviation demand, land use, and energy production.
