I’m A card-carrying greenie, but I can’t pretend that my boyfriend, Gervase, and I decided to travel to Marrakesh by train simply to save on carbon emissions. We were seduced, most of all, by the idea of an adventure: an overland trip through Europe to reclaim the art of old- fashioned train travel. A touch Agatha Christie, we hoped, with one or two James Bond-ish moments.

Our mission was to reach Marrakesh without leaving the ground (or sea). This would involve two night trains, two long day journeys and a ferry. We decided to have an afternoon in Paris on the first day, and stay overnight in Madrid. And part of the plan, of course, was to take the pulse of an alternative approach to travel, one that offered a respite from budget flights.

Using planes like buses is not only unimaginative, but also highly polluting. The boom in cheap flights has made aircraft the fastest growing source of greenhouse gases, but the Aviation Environment Foundation has cautioned that carbon dioxide is more than twice as damaging when released at high altitudes.

It strikes me as silly to obsess over greening up your life in other ways — using public transport, recycling and cutting back on energy in the home — if you’re going to blow tonnes of carbon dioxide by flying around the world (a return flight to New York generates twice as much carbon dioxide as the average UK driver does in a year). It’s time we took a stand against our growing reliance on the skies.

That said, I knew we were pushing it with the distance, but what’s the point of train travel if you can’t get to really exciting places? Early on a Saturday, Gervase and I joined the crowds at the Eurostar platform. By lunchtime we were in Paris, and enjoying a boozy Gallic lunch. For our overnight journey to Madrid we had gone all out on a grand class ticket and were not disappointed. As the Trainhotel rattled through France, we watched the sun plunge into the deep greens of the countryside and toasted our trip with champagne.

Our private couchette began its evening as a salon with two comfortable chairs and a tiny bathroom opposite. Later on, while we devoured a three-course meal in the dining car, staff folded up the chairs and brought down the beds, leaving a chocolate on the pillow as the final touch.

In Madrid we felt the full benefits of overland travel and its ability to offer several holidays for the price of one. The day was spent following the crowds on their Sunday pilgrimage to El Rastro, a sprawling flea market in La Latina district. After checking in to Hostal Madrid on Plaza de Santa Ana, we hit the bar-lined square. Along with the rest of Madrid. We nibbled pinchos (baby sandwiches) of smoked salmon and Serrano ham, swilled down with beer.

At seven the next morning our train began its six-hour journey through the southern half of Spain to reach Algeciras, a port town with hourly ferries to Tangiers. Our hangovers were washed away by watching the landscape, which gradually became craggy and arid as the train wound its way, on a single track, through the olive grove-studded Andalusian hills. A Spanish granny snored in the seat in front of us.

Nobody can complain about a lack of atmosphere when travelling by train. As we inched south, we saw the changing faces of Mediterranean people and felt the sun’s rays strengthen. The air-conditioning, however, was something else. After an intensely cold couple of hours on the ferry crossing and a final night in a couchette travelling down to Marrakesh, our nasal passages were drier than the nearby Sahara.

But we’d made it. Early on Tuesday morning, an ancient Moroccan man woke us to announce that we had arrived in Marrakesh, and thrust cups of hot chocolate into our hands. We had slept wonderfully on our final journey, a testament to the relaxing qualities of train travel.

As for the return journey, we were defeated by time. If we had returned by train to London to make it back by Saturday, it would have left us with just one day in Marrakesh. A budget return flight, by contrast, gave us three days of mint tea and shopping in the souks. On Saturday we left Marrakesh and three and a half hours later were picking up our rucksacks from the luggage carousel at Gatwick.

How did it compare? Well, it was less costly and more convenient than the train, but supremely dull. It was also guilt-ridden, for me. In a bid to recover my green credentials, I paid a modest fee to climatecare.org to offset the carbon emissions for two flights. Next time I’ll take a longer break, and take the train.

Need to know

Getting there: Anna Shepard booked her train journey in Europe through Rail Europe (0870 5848848).

Return fares on Eurostar from London to Paris start at £59. Return fares from Paris to Madrid on the Elipsos Trainhotel start at £163 for a reclining seat and for a Grand Class two-berth sleeper from £320 (both fares include dinner and breakfast on the train). Return fares from Madrid to Algeciras start at £84.

The ferry to Tangiers from Algeciras costs about £23pp and can be booked on the day of travel. The single train trip from Tangier to Marrakesh with couchette costs 290 Moroccan dirhams (£18).

Anna flew with Atlas Blue from Marrakesh to London. One-way flights start at £19.

A double room at Hostal Madrid is about £48.

Climate care: www.climatecare.org .

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