When the invitation to be a bridesmaid at her best friend's wedding arrived at her home in a Welsh woodland a year ago, Barbara Haddrill was both delighted and perturbed.
Far from being concerned about the shape, shade and size of her dress or choice of flowers, the overriding concern for the 28-year-old environmental worker was how to traverse the 10,374 miles from her caravan in a forest in Powys to the nuptials in Brisbane.
For Barbara is no ordinary bridesmaid.
She is the founding member of a new (and hitherto unknown) class of eco-friendly bridesmaids who shun the dubious pleasures of the economy class cabin of an aircraft and instead travel to the wedding by land and sea in the name of the environment.
In less than a fortnight, Barbara and her wedding outfit will board a coach for a 63-hour journey to Moscow on the first leg of a trip that will take up to seven weeks and entail about a dozen different buses, trains and a large cargo vessel. After a break of a couple of months, she will then make the return journey without leaving the ground.
The ecology worker has decided that her planet-friendly principles prevent her from jumping on an aircraft for the 22-hour journey from London to Brisbane at a cost of about £900 and the production of 5.2 tons of carbon dioxide per passenger. The amount of CO2 is equivalent to that generated by heating five modern houses for a year.
Instead, she will spend roughly four times the one-way air fare - and 49 times the journey time - travelling half way across the world for the wedding of her friend and former university colleague, Caroline Cummings. In so doing, she will produce only 1.4 tons of carbon dioxide, the main gaseous culprit for global warming.
For a young woman whose commitment to reducing the impact of the modern lifestyle on the environment means she lives in an old caravan without electricity, heated by a small wood burner, it was the only acceptable solution to the quandary of how to be on the spot to throw confetti in Australia at the end of October.
Such is her dedication to the task she has set herself, Barbara is bringing her teal and blue bridesmaid's dress with her in her rucksack because it would go by air were she to post it.
The intrepid wedding guest, who has worked for the Centre for Alternative Technology in mid-Wales for the past 18 months, said yesterday: "It only dawned on me slowly that I was facing a bit of a dilemma. On the one hand, it was a real honour to be asked to be a bridesmaid at the wedding of a close friend.
"But in order to do that I would by jumping on a plane and negate in less than 24 hours everything I had done in the past six or so years in terms of reducing my carbon emissions. It seemed obvious that I should make the journey more slowly without having a harmful impact on the planet and see so much more of the land and people that lie between."
Indeed, the environmental technologist, whose job before she left her home in Machynlleth, Powys, had been operating a water-powered railway, will spend nearly two months taking in some of most dramatic scenery the planet has to offer.
After travelling from Cardiff to London and then London to Moscow by coach, Barbara will board the Trans-Siberian Railway for the 3,608-mile (5,806km) journey across Russia to the Chinese capital, Beijing. She will then spend up to three weeks crossing China, Vietnam, Laos, Thailand and Malaysia by bus and train before reaching Singapore, where she will pay about £1,000 for a passenger berth on a cargo ship bound from Brisbane.
Ironically, the eco-bridesmaid says her conversion to the environmental cause came after she boarded a flight to Madagascar for voluntary work with a marine conservation project.
Barbara, who met her friend Caroline while studying in Leeds, said: "I'm not pretending I'm whiter than white on these things - I've been on aircraft. Part of the point of doing this is also the adventure. I'm not sure yet how I'll be getting from Beijing to Singapore. I just hope I make it to the church on time."
Her epic journey takes place in the context of ever-increasing debate about the environmental impact of aviation, the fastest-growing source of greenhouse gases. Air transport currently accounts for 3.5 per cent of all man-made emissions responsible for global warming - a figure that is predicted to double within 15 years.
The House of Commons environmental audit committee last week called for an increase in air travel tax to factor in the environmental cost of flying with the number of aircraft in the world set to double to 25,000 by 2025.
With the majority of flights in Europe covering a distance of 310 miles or less, environmentalists say trains can offer competitive travel times across the continent at a fraction of the cost in emissions caused by aviation, which have doubled in the UK during the past 12 years.
Campaigners argue that while the public is increasingly aware of the issue of carbon dioxide generated by jet engines, there is less awareness of other emissions - water vapour and nitrous oxides - which they say can quadruple the impact on the environment.
Tim Johnson, director of the Aviation Environment Federation, said: "We have gone from a situation where two or three years ago the general public were not concerned by the environmental cost of flying to the period of the past 12 months where it has become a hot topic.
"Our research shows there is a majority in favour of paying a green tax on air travel. Such a tax would slow the growth of air traffic in line with the annual increase in fuel efficiency. That at least would be a sustainable aviation policy."
But just how much less damaging to the environment is travelling overland to Australia than hopping on a modern airliner which, according to the aviation industry, generates the same emissions per passenger than a car?
The British Air Transport Association (Bata), which represents the aviation industry, said it accepted that the modes of transport chosen by Barbara were likely to generate fewer emissions than the equivalent journey by air. Bob Preston, Bata's executive officer, said: "We wish her good luck. But not everyone has six or seven weeks of spare time to make the journey she is."
A weblog set up by Barbara, originally to keep friends and family informed of her progress, has attracted a cult following on the internet, including some who are unconvinced at her claims for eco-friendly travel.
One comment on the blog read: "It is going to be a wonderful and unforgettable experience, but cleaner? No way. A modern airliner uses less gas than a car (per passenger), and you're going to find yourself on stinking Russian trucks and buses and, probably, some oil-leaking southern Asian container ship."
Another critic said: "It's oh-so convenient of you to forget what buses, cars and trains run on. I hope you are aware that while planes can be damaging to the environment, your proposed means of transit aren't exactly eco-friendly either.
"Do you really think buses in Siberia run on hybrid engines or that there's a TGV from Moscow to Vladivostok?"
Supporters of Barbara and her journey claim that even allowing for the dirty engines of Soviet-era technology, she will still be performing a valuable task in helping to dismiss the mirage of guilt-free air travel.
Barbara said: "I think it is great that we live in a world where people can go around the world and air travel isn't just for the rich. But clearly it has gone too far - people now fly without thinking about it.
"Maybe it is good to sit back and think about whether it is the best way to travel. I've thought about how I want to spend my money and, even though it's more expensive, this is how I want to do it."Reuse content