After the initial mixture of curiosity and disbelief, the nature of the challenge is remarkably divisive, swiftly splitting people into one of two camps.
Friends either sigh and look at me as a slightly cranky little eco-fundamentalist whose hairshirt notions of green self-sacrifice have led to this daftly complicated and rather inconvenient world mission. Or people's eyes light up at the prospect of a real adventure, of travelling away from the crowd at a different pace and in a very different style.
Don't get me wrong, I'm not an anti-flying fanatic.
I've taken more than my fair share of international flights in my time, working in Jamaica, Australia and the South Pacific as a marine biologist. Maybe this latent carbon guilt has contributed to my decision to undertake this particular journey.
However four years ago I took my last holiday flight to visit friends in Malaga in southern Spain. The work I had been doing on climate change with my company Futerra had convinced me that it was increasingly difficult to justify the environmental impacts of flying purely to indulge myself.
I still visit Malaga, but, thanks to sterling advice from guru Mark Smith, it's a picturesque and relaxing train journey that takes in France, the Madrid plateau and a spectacular route through the Sierra Nevada mountains - a world apart from the cattle-truck mentality no-frills budget airline services of the Sleazyjet sector.
It was this experience and subsequent rail trips to Warsaw and Barcelona that cemented the notion in my mind that travelling without flying really was a more attractive option, and not just environmentally.
You travel through a landscape, not just over it, and see first-hand the transition of scenery, culture, language and people that flying robs you of when it dumps you dazed and disoriented on the other side of the world.
So is it really, in the words of the UK prime minister, "impractical" to expect people not to fly?
Obviously, I believe the answer is no, and I'm putting my time and money where my mouth is to celebrate the joy of slow, low-carbon travel.
At about 7.30am on March 5, I'll be hopping on the 59 bus down Brixton Hill to Waterloo station, to catch a train to Portsmouth where my partner Fi and I will board the ferry to Bilbao. These are the first few steps of a round-the-world journey by land and sea that will take us across Europe to Moscow, then to Ulaan Baatar on the Trans-Mongolian express, into China and down through south-east Asia (Laos, Vietnam, Cambodia, Thailand and Malaysia).
In Singapore we'll catch a container ship to Australia. Then it's over the Nullarbor plain to Sydney and a blagged yacht passage to New Zealand, a brisk tramp through the mountains and another cargo ship from Tauranga to Los Angeles.
We'll skip through Baja California, Mexico, Guatemala, Honduras, Nicaragua and finally to Costa Rica where we will board a banana boat home from Puerto Limon (returning to the UK in appropriate style for all the sceptical mates who think we are bananas for doing this trip in the first place).
We will share the joys, pains, trials, tribulations and inevitable adventures of the next 12 months with you through this blog - there will be tears, there will be laughter, the one thing there won't be is deep vein thrombosis.
Are we nutters? Maybe. But as the old adage goes ..."civilisation is the slow process of adopting the ideas of minorities". Here's to the joy of slow!
Ed Gillespie is creative director of Futerra.