Some popular holiday destinations are paying tourists who behave well and offering other rewards.

The different measures have been implemented in cities around the world so make sure they are environmentally sustainable and ensure that tourists do not cause unwanted chaos during their stays.

In Denmark’s capital, Copenhagen, a system called ‘CopenPay’ rewards tourists with free food and activities if are environmentally friendly.

Kristijan Svajnzger, Regional General Manager for Northern Eastern Europe at Intrepid Travel, said of the scheme: “This is a great way to educate and reward people who are doing the right thing rather than penalize people who are doing the wrong thing when it comes to sustainability.”

Visitors can get rewards if they help with litter picking, using public transport, and getting around the city by bike.

In Iceland and New Zealand, tourists are asked to take an online ‘tourism pledge’ – vowing to behave responsibly.

There is even a slogan in Iceland that says: “When nature calls, I will not answer the call on nature”.

These kinds of measures have been adopted in the UK too,

Krissy Roe, senior sustainability manager at Inghams, explained why her company is offering £200 off holidays to returning guests if they travel by train.

She said: “We’re also seeing more and more hotels and destinations around the world rewarding their customers for ‘greener’ behaviour – a welcomed trend.”

In the Alps some regions are giving tourists 25 per cent off ski passes if you travel there via train.

Mas Pelegri, an eco-hotel in Girona, Spain, gives guests £50 discount if they travel there by rail.

Quinta Alfarrobeiram B&B in the Algarve, has warned that public transport infrastructure will need to be bolstered in Europe to accommodate the increasing number of people traveling by train.

They said: “Unfortunately, the infrastructure, in particular railways, is not really prepared for the change that’s so desperately needed.

“Of course, it takes more time to travel over land, but to encourage you to do so, we like to compensate a bit.”

They give tourists a free night if they do not travel there by plane.