Flying with British Airways can increase CO2 emissions by as much as 45 per cent per passenger compared to rival airlines, according to an investigation.
The snapshot analysis found that one passenger flying from Heathrow to Miami with British Airways would be responsible for 1.13 tonnes of carbon. The same journey with Virgin Atlantic is responsible for about 860.9 kilos.
The difference – 544 kilos of CO2 for a return journey – is about the equivalent of more than two months of electricity in the average UK home, according to Which.
Researchers said flag carriers such as British Airways “tend to have wider fleets of wide-bodied aircraft, which use more fuel”.
They often carry more business and first-class passengers than their rivals. These customers are afforded more space in the cabin, bringing down the number of overall passengers and giving the flights a larger carbon footprint.
However, British Airways hit back at the research, claiming it was based on “data which is several years out of date”.
“The conversation about climate change is too important to be undermined by … Which using shoddy research,” they said.
“Which only looked at two per cent of our flights and their paid-for calculations, hidden behind a pay wall, are completely at odds with the figures calculated by the range of airlines they claim to have investigated.
“We are committed to net zero by 2050 and we are open to discussion on our approach to reducing our carbon emissions with anyone who is interested in accurate and robust data.”
Last year an investigation into airline carbon emissions uncovered that British Airways emits 18,000 tonnes of additional CO2 each year by indulging in a practice designed to save money.
So-called “fuel tankering”, involves filling aircraft with extra fuel to avoid having to refuel in destinations where prices are higher.
Rory Boland, Which travel editor, said: “These figures show that swapping to a greener airline will allow the many of us concerned about climate change to immediately and significantly reduce our individual carbon footprint.
“If millions of us were to switch to a less polluting airline on our next holiday, it would bring pressure to bear on the worst polluting airlines and force them to prioritise their impact on the environment by introducing more efficient aircraft and cleaner fuels.”