Sustainable tourism: The 20 biggest issues facing travellers and what you can do

WHAT THEY SAY Barcelona and Venice, Dubrovnik and Iceland: increasingly, destinations are declaring themselves fed up with floods of tourists crowding their streets.

WHAT WE SAY Overtourism is often about "when" rather than "where". Even Venice can be crowd-free if you visit in the cooler months.

WHAT YOU CAN DO Perhaps, counter-intuitively, spending longer in a destination helps reduce crowding, as long-stay visitors tend to move around the entire city rather than just hitting the must-see spots. And, of course, longer stays give you a more in-depth experience.

THE ISSUE: ANIMAL PROTECTION

WHAT THEY SAY From dolphins bred in captivity to tourists posing for photos with lion cubs, awareness of animal exploitation is rising.

WHAT WE SAY According to World Animal Protection (WAP), more than 3000 captive elephants are used in tourism in Asia – that's 30 per cent more than five years ago. WAP found that 96 per cent of venues offering elephant rides keep their animals in unacceptable conditions.

WHAT YOU CAN DO This one is simple: avoid all activities which involve taming or training wild animals.

THE ISSUE: VOLUNTOURISM

WHAT THEY SAY What could possibly be wrong with heading to a foreign country to make a difference, perhaps helping out in a school or hospital? Critics say that voluntourism is a short-term fix that ignores the systemic root of the problems.

WHAT WE SAY Studies have documented shocking cases of unqualified volunteers actively displacing health professionals and taking work opportunities from locals.

WHAT YOU CAN DO Pick your project carefully: look for a charitable organisation with transparent processes and outcomes that doesn't cut across existing aid initiatives. Citizen science projects run by environmental charity Earthwatch are a good choice.

THE ISSUE: CHILD PROTECTION

WHAT THEY SAY Remember orphanage tourism? Travellers flocked to spend an afternoon playing with "orphans", until it became clear that not only were some of the children not actually orphans, but that exposing children to endless strangers isn't a great idea.

WHAT WE SAY Orphanage visits may be a thing of the past, but child exploitation is still way too common. Never buy from children or give them money – all you are doing is turning children who should be at school into income earners.

WHAT YOU CAN DO A simple rule: if you wouldn't want someone doing it to your child, don't do it to someone else's. (Yes, that includes handing out sweets.) if you want to help, donate to a reputable charity or NGO.

THE ISSUE: FLIGHT SHAMING

WHAT THEY SAY Air travel generates around 5 per cent of the world's carbon emissions and passenger numbers are expected to double in the next two decades. The flight shaming movement urges travellers to choose alternatives such as train travel.

WHAT WE SAY Flight shaming has swept Europe, a continent with excellent rail and road links, but is less popular in the United States and Australia, where distances are much longer.

WHAT YOU CAN DO Apart from investing in carbon offsets, rethink your long-haul trips. Instead of hopscotching across Europe, for instance – flying from Paris to Berlin to Moscow – consider basing yourself in one spot and exploring the surrounding area in depth.

THE ISSUE: HOME RENTALS

WHAT THEY SAY It's known as the Airbnb effect: landlords listing their properties on online rental platforms such as Airbnb, leaving locals struggling to find somewhere to live.

WHAT WE SAY It is ironic that a business selling the idea of "living like a local" has led to crippling rent increases. On the upside, however, online platforms now give exposure to traditional pensiones and guesthouses.

WHAT YOU CAN DO Renting an Airbnb room in a remote, rarely visited village is a very different thing to booking yourself into a centrally located apartment in Amsterdam, so use the technology wisely. And remember that locally owned hotels, hostels and guesthouses are a great alternative.

THE ISSUE: INFECTIOUS DISEASES

WHAT THEY SAY Zika. Ebola. Cholera, malaria, HIV, swine flu, bird flu – all dangerous diseases ready to strike down the unwary traveller. The rise of drug-resistant microbes just adds to the fear factor.

WHAT WE SAY News flash: travellers are not only victims of diseases, they are also carriers. And it's not just exotic diseases that are dangerous, as a number of measles outbreaks spread by travellers have recently shown.

WHAT YOU CAN DO Keep your immunisations up to date, including measles, mumps and rubella. If you are taking antibiotics, finish the entire course. And, of course, don't leave home without comprehensive travel insurance.

THE ISSUE: TOURISM BOYCOTTS

WHAT THEY SAY Some countries should be no-go zones. Rather than supporting a corrupt or authoritarian regime, travellers should spend their money elsewhere.

WHAT WE SAY You can find reasons to boycott just about any country if you try. Australia could be targeted for our track record on Indigenous health, treatment of refugees and even the state of the Great Barrier Reef. And who gets hurt most by boycotts? Not the government, but locals trying to eke out a living from tourism.

WHAT YOU CAN DO Wherever you choose to travel, do your research and travel with a company that supports local business and communities.

THE ISSUE: WILDLIFE VIEWING

WHAT THEY SAY According to a UN report released in May, one million of the world's species are under threat from extinction. We are in the middle of the biggest spate of extinctions since the disappearance of the dinosaurs and species from lions to polar bears are vulnerable. Some say that taking a safari to see these animals is akin to a death watch.

WHAT WE SAY Tourism is actually the best hope for many species. It is particularly in areas where animals are subject to poaching, that wildlife tourism can give locals an alternative income stream.

WHAT YOU CAN DO Choose an operator with a commitment to conservation, such as African specialists Wilderness Safaris or andBeyond.

THE ISSUE: THE TROUBLE WITH TREKKING

WHAT THEY SAY High-altitude treks are often based on the exploitation of local porters, who work long hours, carrying huge weights, for very little money.

WHAT WE SAY A number of international companies and porters' organisations have banded together to support porters' rights and identify local issues. One Nepalese study found that porters suffer four times as many accidents and illnesses as trekkers.

WHAT YOU CAN DO International organisations follow set standards on minimum wages, maximum loads and educational initiatives, but some smaller local companies don't. Opt for an organisation that advertises its commitment to porters' rights – and give your porter a generous tip.

THE ISSUE: CRUISE IMPACTS

WHAT THEY SAY The downsides of cruising: carbon emissions and dangerous particulates generated through heavy fuel oil, along with some cases of dumping rubbish, fuel and sewage into the ocean.

WHAT WE SAY Almost every choice a cruise company makes, from the fuel it uses to the shape of the ship's bow, to how it treats wastewater, has an impact on the environment, and standards vary across the industry.

WHAT YOU CAN DO Choose one of the cruise companies switching from heavy oil to liquefied natural gas, electric and battery power. If you are heading to a fragile environment such as Antarctica, look for a cruise company affiliated with the International Association of Antarctic Tour Operators, which imposes strict regulations.

THE ISSUE: SLUM TOURISM

WHAT THEY SAY To its supporters, slum tourism – visiting deprived neighbourhoods in cities such as Rio, Cape Town and Mumbai – replaces stereotypes with reality. To its detractors, it turns human beings into exhibits. As a former resident of Nairobi's Kibera slum wrote in The New York Times, "They get great photos, we lose a piece of our dignity."

WHAT WE SAY It all depends on which tour operator you choose. Some work closely with the communities and have strict guidelines. Some even ban the taking of photos.

WHAT YOU CAN DO Ask whether the company uses locals as guides, and what percentage of their profits goes to the community.

THE ISSUE: FRAGILE ENVIRONMENTS

WHAT THEY SAY As cities grow ever larger, travellers are increasingly keen to experience true wilderness. Unfortunately, tourism can pose a threat to these destinations – and we're not just talking about Antarctica.

WHAT WE SAY An example close to home: during one of the recent floods of Australia's largest lake, Kati Thanda-Lake Eyre, experts warned visitors that by gathering firewood they were destroying the natural habitats of insects and small mammals.

WHAT YOU CAN DO Be aware of your destination's issues before you head off. Even something as simple as vibrations from jet skis have caused behavioural change among marine creatures in some destinations.

THE ISSUE: DISASTER TOURISM

WHAT THEY SAY When disaster strikes, tourism plummets, and so do prices. Adventurous visitors willing to travel anyway can score a bargain, while locals get some much-needed income. What's not to love?

WHAT WE SAY Destinations may desperately need the income, but tourists visiting too soon can consume resources needed by locals or relief workers. In New Orleans after Hurricane Katrina, the community complained about visitors turning their suffering into a spectacle.

WHAT YOU CAN DO For every New Orleans, where locals campaigned to get tours banned, there is a Nepal, where tourism dollars were vital to helping communities rebuild after the 2015 earthquake. Do your research and apply some commonsense.

THE ISSUE: PLASTIC POLLUTION

WHAT THEY SAY The plastic straw is public enemy No. 1. Hotels, resorts and cruise lines around the world have all banned plastic straws in an effort to curb plastic pollution.

WHAT WE SAY Clearly it's not that simple. Just about any journey you take will involve endless excess plastic, from the mini shampoos in the hotel to that bottled water you just bought.

WHAT YOU CAN DO Hotel chains such as Intercontinental Hotel Group and Marriott are ditching mini toiletries and you can do your bit by thinking ahead. Pack a refillable drinking bottle (with water filters, if necessary), reusable cutlery and some reusable carry bags for any shopping you do.

THE ISSUE: WATER CONSUMPTION

WHAT THEY SAY Last year's drought in Cape Town and earlier shortages in Sao Paulo are just the start. Other destinations facing water shortages, according to the International Tourism Partnership (ITP), include Bali, Mumbai, Delhi and Bangkok.

WHAT WE SAY Tourism exacerbates the problem, with hotel guests typically using more water than locals. ITP estimates that by 2030, one third of the world's population will be living in areas of severe water stress.

WHAT YOU CAN DO Australians tend to be pretty water-wise, so keep that behaviour up on holiday. Small measures – shorter showers and turning off the tap while you brush your teeth – make a big difference.

THE ISSUE: INSTAGRAM TOURISM

WHAT THEY SAY When images of Norway's remote Trolltunga cliff went viral on Instagram, visitor numbers skyrocketed from 500 people to 40,000 annually. The result? Long queues of people waiting to get their shot, destroying the isolation that was once the attraction.

WHAT WE SAY Snap-happy crowds aren't the only downside of Instagram. Travellers in search of the perfect shot are also becoming reckless, with several selfie deaths around the world.

WHAT YOU CAN DO We all treasure a great holiday snap, but a trip should be about more than just photos. Tell the truth on social media: if you had to queue for hours to get a shot, say so.

THE ISSUE: REEFS AT RISK

WHAT THEY SAY With coral reefs in crisis, tourism can be a lifeline: the more money generated by tourism, the more likely governments are to try to help preserve them.

WHAT WE SAY Tourism can also have negative impacts, from careless visitors damaging coral to the recent discovery that even relatively low amounts of artificial light at night can disrupt the breeding cycle of clownfish, which has implications for overwater accommodation.

WHAT YOU CAN DO Travel with reputable operators who are committed to protecting the reef, and slap on a mineral sunscreen – chemical sunscreens are toxic to reefs.

THE ISSUE: INDIGENOUS ENCOUNTERS

WHAT THEY SAY The Jarawa people of the Andaman Islands had little contact with the outside world until two decades ago. When tourists started visiting, some operators introduced human safaris, with the Jarawa forced to dance in exchange for food.

WHAT WE SAY Done properly, tourism can help First Nations people boost their economy while maintaining their culture. Operators such as World Expeditions and Intrepid Travel work closely with communities so they can identify and manage likely impacts before they launch any trip.

WHAT YOU CAN DO Ask questions: how long has the operator been working with the community, how does the community benefit from the trip?

THE ISSUE: CHANGING SKI SEASONS

WHAT THEY SAY European glaciers are in retreat; US snow cover has dropped by 40 per cent. Ski fields are increasingly relying on snowmaking to cover their slopes, using enormous amounts of water and energy.

WHAT WE SAY The meltwater from man-made snow, which contains more minerals and nutrients than natural snow, can change local flora, which in turn impacts the summer tourism initiatives that are increasingly important in many ski areas.

WHAT YOU CAN DO Higher slopes naturally have more snow, making high-altitude skiing the greener choice. If you love mountain landscapes, consider taking a summer trip instead, which has fewer impacts.

AND NOW, THE GOOD NEWS

FLYING HIGH

Airlines such as Qantas, Virgin and ANA are investing in biofuels, while manufacturers are working on electric aircraft. Norway has announced that all domestic flights from its airports will be electric by 2040.

EATING GREEN

Vegan and vegetarian food has gone mainstream, with groups such as Four Seasons now offering vegan menu choices. Virgin Airlines has removed beef from some of its flights to reduce greenhouse emissions, while Air New Zealand says it won't serve prawns until they can be sustainably sourced.

SMOOTH SAILING

More efficient ship designs reduce drag and thereby improves fuel efficiency, while companies such as Royal Caribbean are partnering with organisations such as the World Wide Fund For Nature to reduce environmental impacts.

KEYS TO SUCCESS

Hotel check-ins that let you use your smartphone instead of a key aren't just convenient, they are also good news for the environment. Turns out that the manufacturing process for PVC key cards is highly toxic.

BETTER BUILDINGS

Buildings are getting smarter. Parkroyal on Pickering hotel in Singapore (above), for instance, is designed to maximise natural light, harvests rainwater and uses automatic sensors to regulate energy and water.

LAW OF NUMBERS

With overtourism an issue around the world, governments are increasingly legislating to manage the impact. From Santorini to Machu Picchu, popular destinations are restricting visitor numbers and trying to counter the rental hikes associated with online rental platforms.

PICK UP ARTISTS

One of the unlikeliest trends sweeping the travel world is travellers picking up other people's litter. The Ten Pieces campaign (in which travellers gather 10 pieces of litter while they are hiking) has been a huge success, while properties such as Bungaraya Island Resort in Borneo are introducing their own programs.

WASTE NOT

Recycling is now mainstream. The Walt Disney Company is aiming for 60 per cent waste diversion by 2020, with one Disneyland Park attraction having already hit its zero waste target. Airlines are also signing up: LATAM recycles aluminium, glass and plastic from its meal service.

FOCUSING ON FOOD

Six Senses Zil Pasyon resort in the Seychelles cut food waste by 23 per cent in a month through measures including changing portion sizes. Bigger chains are following suit, with Marriott aiming to halve food waste by 2025.

NATURAL FORCES

Renewable energy is everywhere, from solar-powered tropical retreats to Scandinavian resorts drawing on geothermal energy. Note to eco-aware travellers: Iceland generates 100 per cent of its energy from renewables, giving the entire country a green glow.

TRIP HAPPY WITH THESE ETHICAL TRIPS

CRUISE CROATIA'S COAST

Responsible Travel's plastic-free trips includes this eight-day small-ship cruise. Visit the ports of Split and Hvar as well as wineries and the stunning Krka National Park. From £1211 a person. See responsibletravel.com

ETHICAL ELEPHANT SAFARI

Enjoy an ethical animal experience with three days in Nepal's Chitwan National Park. Travellers can walk alongside elephants that live chain-free in spacious corrals at a facility rated nine out of 10 by World Animal Protection. From $1090 a person. See worldexpeditions.com

KENYA WOMEN'S EXPEDITION

This 10-day women-only trip offers not just safari action but also close encounters with women from across Kenya. Accompanied by East Africa's first female overland truck driver, meet female rangers and spend time at a women-only village that offers sanctuary to victims of rape and forced marriage. From $3850 a person. See intrepidtravel.com

CALVADOS ATOLL KAYAK EXPEDITION

Spend eight days paddling over coral reefs, pulling up on sandy beaches and camping under a starry sky, while getting to know some of Papua New Guinea's Indigenous people. From $3850 a person. See southernseaventures.com

PERU ULTIMATE ECO EXPERIENCE

This 11-day tour takes in destinations including Machu Picchu and the Incan capital of Cusco as well as the tropical rainforest. Sleep in eco-lodges that use renewable energy and hotels that raise funds for children's charities. From $3385 a person. See chimuadventures.com