Despite more flights entering and leaving the UK as a whole in 2021, the number of passengers fell to a record low, sparking criticism from environmental organisations over the impact on the climate of running emptier flights.
Civil Aviation Authority data shows 43,674 planes took off or landed at Edinburgh airport in 2021.
This was down five per cent from 45,966 in 2020, and the lowest number since comparable records began in 2010.
By comparison, there were 131,617 flights in 2019, before the coronavirus pandemic.
Last year saw just 1.6 million flights to and from UK airports – the second-lowest number since 2010, but up from 1.5 million in 2020.
However, despite a rise in the number of flights nationally, the figures show the number of passengers passing through UK airports fell from 74.4 million to 65.4 million – the lowest on record.
This suggests planes were carrying fewer passengers than ever last year.
Dr Doug Parr, chief scientist for Greenpeace UK, said: "The aviation industry is perfectly happy to release climate-wrecking emissions even when there aren’t enough passengers for them to make them any money from it. Anyone who claims that they’ll decarbonise without being legally compelled to do so is comically naïve.”
A total of 3 million passengers boarded or got off domestic or international flights at Edinburgh airport last year. This was a decrease on the 3.5 million passengers who used the airport in 2020, and on 14.7 million in 2019.
Anna Hughes, director of campaign group Flight Free UK, said all flights harm the climate – not just empty ones – but that it is "ludicrous" that planes are flying half-empty.
She added: "This is a critical time for the climate and we should be reducing our fossil fuel use, not burning it unnecessarily in near-empty flights.
"The laws of supply and demand say that fewer people flying should mean fewer planes in the air, but somehow this is not reflected in airlines' habits."
Meanwhile, separate figures released by the Department for Transport show 14,500 so-called 'ghost' flights took place over a 19-month period during the pandemic.
The international flights, which had no more than 10 per cent of their seats filled, were operated mainly to transport cargo or repatriate Britons stranded overseas.
Of these, 552 occurred at Edinburgh airport between March 2020 and September 2021.
Airlines have traditionally run ghost flights when they need to hit the 80 per cent threshold for using valuable take-off and landing slots at congested airports to retain the right to use them during the following year.
Slot rules were suspended at UK airports shortly after the start of the pandemic but were reintroduced at 50 per cent in October 2021.
Ms Hughes said the practice appears to show airlines are “focused on growth at all costs”.
But a DfT spokeswoman said: “Flights may operate with low passenger numbers for a whole range of reasons, including carrying key workers or vital cargo.
"However, we acted swiftly to prevent empty aircraft needing to fly solely to retain their slots.”