Overtourism and the big chill

The tourism industry is booming as travellers find ever more intrepid ways of exploring the globe and receding security fears revive old favourites.

But as industry professionals descend on Berlin for the ITB fair, the world's largest travel trade show, the news isn't all good.

Some of the most popular destinations are becoming victims of their own success, leaving the sector scrambling to respond to concerns about overcrowding and environmental damage.

Here's a look at the themes expected to dominate this year's ITB, which runs from Wednesday until Sunday.

Middle East comeback

Egypt, Tunisia and Turkey all suffered steep drops in visitor arrivals in recent years after a series of terror attacks and bouts of political instability. But a period of relative calm has tempted tourists to set their fears aside and rediscover these classic destinations, lured by the promise of sun, sea and rock-bottom prices.

In Egypt alone, arrivals more than doubled in 2017, according to the World Tourist Organization.

Tunisia, badly shaken by a museum attack and beach shooting in 2015 that together killed 60 people, saw tourist arrivals jump by more than a third last year.

The Palestinian territories are tipped as an up-and-coming destination, while Israel, despite a tense security situation, has seen a spike in bookings following a no-expenses-spared promotion campaign.

Winter is coming

Some of this year's hottest destinations are also the coldest, with growing numbers of holidaymakers prepared to shiver to experience the other-worldliness of Lapland, Greenland or Antarctica, or the breathtaking colour show of the Northern Lights.

Iceland owes its unprecedented tourism boom in part to "Game of Thrones" fans eager to explore the wild landscapes that featured in the television show. In 2017, the country with fewer than 340,000 residents welcomed a staggering 2.5 million visitors.

- Overtourism –

While the money they bring may be welcome, the hordes of tourists in places like Iceland has sparked a backlash among locals, who complain that their nation's pristine locations are being overrun.

The grumbles have been even louder in perennially popular places like Barcelona, Amsterdam and Venice, where residents are increasingly fed up with the crowds, the strain on public infrastructure and unaffordable rents as city centre flats become Airbnb holiday lets.

Authorities have started to take notice, vowing measures to curb the influx –- and posing fresh challenges to the travel industry.

"So-called overtourism has become a major problem this year," the IPK International tourism consultancy said in a recent report. "The industry urgently needs to find answers."

Mixing business with pleasure

Flexible working hours and jobs that can be performed anywhere with wifi have blurred the lines between travelling for business or leisure.

These so-called "bleisure" travellers, mainly aged 18 to 34, are free to book a beach escape on a whim or tag a few extra days onto a business trip to do some sightseeing -- so long as their tech needs are met.

Thailand, determined to tap into these affluent digital nomads, has embarked on a major push to boost its high-speed internet infrastructure, including on its most remote and picturesque islands.

- Every drop counts -

Hotel guests have long been used to the little cards in the bathroom asking them to re-use their towels. But as environmental pressures grow, hotel chains and tour operators are going a step further, bringing eco-friendly travel into the mainstream.

To encourage responsible water use, it is becoming increasingly rare to find large baths in hotel rooms, even in luxury establishments, according to the specialist magazine Travel Weekly.

In drought-hit South Africa, hotels have taken action to reduce their laundry loads by switching to paper napkins and washing the linen less frequently.

In Norway, the government is planning tough new restrictions on cruise ships entering its spectacular fjords in a bid to lower harmful emissions and crack down on pollution.