For many people summer means holidays. And for York, holidays – or to be more accurate, visitors – keep the place ticking over.

The statistics make interesting reading. According to the York Visitor Survey 2015, every year we welcome 6.9 million visitors who spend £564million, thereby supporting no less than 19,000 jobs.

A quarter of these visitors will stay at least a night in one of the city’s 16,000 rentable bed spaces. One in eight will come for a conference or other work-based reason, but 231,000 will have jetted in from all over the world.

Americans and Chinese top the nationalities drawn to our ancient town on the Ouse, with plenty of Australian, Germans and Spanish visitors in the crowd to keep them company.

Of course, the rapid growth of holidays and travel since the Second World War has created wonderful opportunities to enrich our lives. Never before have all the corners of our planet been so accessible. Foreign travel in particular was a preserve of the wealthy, with working people only able to afford a week by the sea, at best. However, there are signs humanity’s love affair with travel and holidays might be under pressure.

Last year saw angry marches protesting against the damaging effects of tourism in Barcelona and Venice. And this year Amsterdam has joined the backlash, with the city authorities and locals complaining about hordes of people choking narrow streets and effectively pricing out residents. The knock-on effects for ordinary citizens have made whole areas unliveable, with shops like bakers or pharmacies replaced by souvenir sellers, bars and ranks of restaurants.

The Japanese city of Kyoto has become so worried by what it dubs “tourist pollution”, that it has just introduced a new law requiring property owners to register with the government before they can legally make their homes available through Airbnb and other websites. The restriction has already caused the number of available properties to plummet and has cost the US-based company millions of dollars.

York itself has seen a rapid rise of Airbnb and this change of use from ordinary home to commercial property is controversial. As a city we are facing a housing crisis caused by a number of factors. Many York citizens are in low-paid jobs and simply cannot afford the city’s high rents and house prices. In addition, large numbers of visitors and students in the city create a natural squeeze on the housing supply.

Our love of holidays has another cost. All forms of travel that involve burning fossil fuels come at a high environmental price. Millions of UK visitors to York are unwittingly adding to climate change through the exhaust pipes of their cars, coaches and trains. As for overseas visitors flying into the UK, there's no avoiding the fact that air travel is very bad news for the environment. Put bluntly, planes are worse than most other forms of transport in terms of the impact of greenhouse gases per passenger mile.

Given that last week alone, two studies by scientists published in Nature magazine revealed the Antarctic is melting at a record-breaking rate, we should all be alarmed. Ironically, the studies found the subsequent sea level rises could have catastrophic consequences for cities around the world, including low-lying communities like Venice and Amsterdam, the same people who are complaining so vociferously about tourism. By that reckoning they face a double whammy. And given York’s own flood-troubled history, we cannot afford complacency either.

It is possible mankind is entering a new era where assumptions that we have the right to holiday in far-flung lands must come to an end. If so, many of us will feel a great sense of loss. After all, life has been compared to a journey since the dawn of time and we learn through travel.

However, such a change might bring unexpected rewards. The great Chinese philosopher Lao Tzu wrote: “A good traveller has no fixed plans and is not intent on arriving”. Maybe we will be forced to appreciate emotional, spiritual and intellectual travels closer to home. Or even live more fully in the here and now. And who is to say we wouldn’t be happier for it.