While 26 of his colleagues in Lithuania’s delegation to COP26 reached Glasgow by private plane or on commercial flights, Marijus Gailius wanted to do the right thing.
As a communications assistant for the ministry of climate change, Gailius figured he’d avoid flying from Vilnius to Glasgow and instead make the journey by land and sea, a trip of some 2,500 kilometres.
Unlike the representatives of some European governments that have made much in the media of their 27-hour sleeper train journeys to Glasgow, Gailius made the journey in his own time - and at his own expense. The cost? More than €300, compared to around €30 on a budget flight.
But it was better for the environment, right? Wrong.
Gailius meticulously calculated his carbon footprint as he took four buses, a ferry, a train and another bus from his home in Vilnius to COP26 in Scotland.
They included a bus from Vilnius to Bialystok, in Poland, another bus from Bialystok to Poznan and then a car share from Poznan to Berlin. After a night in Berlin, he took a night bus to Amsterdam - during which he got no sleep - followed by the ferry from Amsterdam to Newcastle.
He worked out that due to pandemic restrictions on passenger numbers - several of the buses he took were half full - and a 17-hour ferry from Amsterdam to Newcastle, which was also half full, it would have been better for the climate to have flown.
It also would have been cheaper.
Perhaps it is no surprise, therefore, that Gailius will be returning to Vilnius on Friday by plane.
“I am coming back, at the government’s expense, by plane,” he told Euronews.
“It is just too exhausting to go via alternative travel.”
The trip has been something of a revelation for Gailius, who described in his article for Lithuanian media watching the factories pumping black smog into the sky and the container ships loading and unloading freight in Amsterdam.
He came to the realisation that individuals can do little to make a real impact on global emissions.
“No matter how hard we try to save the planet, we will not stop the climate crisis with individual efforts. Let’s not fool ourselves, as long as it is possible to choose a cheap flight, people will choose it,” he wrote in an account of his journey for a Lithuanian media website.
“As my experiment has shown, behaving differently is not only practical but also... pointless.”
Gailius hasn't given up on eco-friendly travel. In 2015 he travelled to COP21 in Paris using buses, trains and taxis rather than fly and had more success than this year's journey.
But right now, the experience of his nightmare journey to Scotland is still raw.
"At this moment I think I would not [do it again]," he said.
"But when I come back to Vilnius I am sure I will [recover]. I stopped flying for my holidays years ago."
A European Environment Agency report last year found the train is the greenest form of travel -- after cycling and walking -- and that aviation is invariably worse on a per passenger, per kilometre basis. But aviation is not always the most harmful choice when it comes to your carbon footprint, it adds. It says travelling alone in a diesel or petrol-powered car can sometimes be worse.