The Carbon Footprint of Global Tourism

Year after year, global tourism sells a simple promise: escape. But behind cheap flights and sunset selfies sits a very real, very measurable climate cost. In 2019, just before the pandemic, new research estimated that tourism’s total carbon footprint reached roughly 5.2 gigatonnes of CO₂-equivalent (Gt CO₂-e)—about 8.8% of all global greenhouse gas emissions that year.

This article unpacks where those emissions come from, how they changed during and after COVID-19, and what can realistically be done to bring tourism in line with climate goals.

1. How big is the carbon footprint of global tourism?

1.1 What counts as “tourism emissions”?

When researchers talk about tourism’s carbon footprint, they usually include:

• Direct emissions:

  • Fuel burned in planes, cars, buses, cruise ships, ferries and trains used for trips.

  • Energy used in hotels and other accommodations (electricity, heating/cooling, hot water).

• Indirect (supply-chain) emissions:

  • Emissions from producing aviation fuel, building planes and cruise ships, constructing airports and resorts.

  • Food and beverages, souvenirs, events, and other services that tourists consume.

A landmark study led by the University of Sydney’s Manfred Lenzen followed tourism-related spending across 160 countries and through global supply chains. It concluded that tourism accounted for around 8% of global greenhouse gas emissions between 2009 and 2013, a much higher figure than earlier, narrower estimates that focused mainly on transport.

More recently, a 2024 study in Nature Communications updated this picture and found that:

• Global tourism emissions grew about 3.5% per year between 2009 and 2019,

• Reaching about 5.2 Gt CO₂-e in 2019,

• Equal to around 8.8% of total global GHG emissions.

By comparison, the entire global aviation sector (not just tourism-related flights) emitted about 950 million tonnes (0.95 Gt) of CO₂ in 2023, roughly 2.5% of global energy-related CO₂ emissions, according to the International Energy Agency (IEA).

So tourism as a whole is a much bigger climate player than people usually assume—roughly on par with the emissions of major industrial sectors or large emitting countries.

2. Tourism’s emissions in context: growth, collapse, rebound

2.1 The pre-pandemic peak

According to UN Tourism (UNWTO), 2019 was a record year:

• 1.5 billion international tourist arrivals, up 4% from 2018 and the tenth consecutive year of growth.

At that point, tourism represented around 10% of global GDP and 10% of employment.

Overlay that with the 2024 tourism-emissions study, which shows tourism reaching 5.2 Gt CO₂-e in 2019, and you get a picture of a sector whose emissions rose faster than the global economy: tourism’s carbon footprint grew around 3.5% annually between 2009 and 2019, roughly double the growth rate of global emissions overall.

2.2 COVID-19: a forced decarbonization experiment

Then came 2020.

Travel restrictions and lockdowns produced the worst year in tourism history:

• International tourist arrivals fell by about 74% in 2020 compared with 2019.

Using the 1.5 billion arrivals in 2019 as a baseline, that implies only about 390 million international trips in 2020. That unprecedented drop in travel led to a huge (but temporary) reduction in tourism-related emissions as planes idled, cruise ships docked, and hotel occupancy collapsed.

By 2022, the recovery was in full swing:

• More than 900 million international tourists travelled that year—about 63% of pre-pandemic levels.

In 2023, tourism nearly closed the gap:

• Around 1.3 billion international arrivals, roughly 88% of 2019 levels, according to UN Tourism’s January 2024 barometer.

In 2024, international tourism essentially returned to “normal”:

• Roughly 1.4 billion trips, about 99% of 2019 levels, with some destinations exceeding their pre-COVID records.

And by 2025, tourism had moved beyond recovery into new record territory:

• An estimated 1.52 billion international tourists worldwide, about 3% above 2019.

Given how closely tourism emissions track travel volumes, it’s reasonable to infer that global tourism’s carbon footprint in 2024–2025 is now back at, or slightly above, its 2019 peak, unless strong mitigation measures cut emissions intensity per trip—which evidence so far suggests is happening only slowly.

3. How tourism emissions break down by sector

Tourism’s climate impact is heavily skewed toward transport—especially flying—but every part of the travel experience has a footprint.

A widely cited estimate from a joint report by UNWTO and UN Environment Programme (UNEP) found that in 2005:

• Tourism contributed about 5% of all anthropogenic CO₂ emissions, and

• Transport accounted for 75% of tourism’s CO₂ footprint, with air transport alone responsible for 40%.

That early breakdown is summarized below.

Table 1 – Sub-sector contributions to tourism CO₂ (circa 2005)

Source: UNWTO & UNEP, “Climate Change and Tourism – Responding to Global Challenges”; UN Tourism/ITF modelling.

More recent literature suggests that aviation’s share has grown further, with some analyses now describing aviation as responsible for over half of tourism’s greenhouse gas emissions, as long-haul air travel has boomed much faster than low-carbon options like rail.

Below, we zoom into each major source.

4. Aviation: tourism’s largest and fastest-growing emitter

4.1 Global aviation emissions in numbers

Aviation is small compared to total global emissions—but enormous compared to the footprint of an individual traveler.

Key data points:

• Globally, aviation accounts for about 2.5% of CO₂ emissions and around 4% of historical warming.

• The IEA estimates aviation emitted ~950 Mt CO₂ in 2023, over 90% of pre-COVID levels and growing again as passenger demand sets new records.

• An analysis by the International Council on Clean Transportation found that commercial passenger aviation emitted about 90 g of CO₂ per passenger-kilometer in 2019—equivalent to around 124 kg of CO₂ for an average one-way flight of 1,378 km (about London–Rome or New York–Miami).

Short flights are worst on a per-kilometer basis because takeoff and landing are fuel-intensive. One comparison found short-haul flights at around 150 g CO₂ per passenger-km, versus just 4 g per passenger-km on high-speed electric rail like the Eurostar.

Add to this the non-CO₂ effects of aviation—nitrogen oxides, water vapor, and contrails at high altitude—which roughly double aviation’s effective warming impact over CO₂ alone, according to climate-science assessments summarized by Our World in Data and IPCC working groups.

4.2 Tourism’s share of flying

Not every flight is for leisure, but tourism occupies a huge share of passenger aviation:

• Pre-COVID, international tourism growth significantly outpaced global GDP growth, underpinned by affordable air travel and expanded route networks.

• Studies of global tourism emissions conclude that air travel is the single largest contributor to tourism’s footprint, especially for high-income travelers taking long-haul trips.

Meanwhile, aviation is also highly unequal. Research on frequent flyers suggests that around 1% of the world’s population is responsible for half of aviation emissions, where private jets are responsible for approximately 5–14 times more emissions per passenger than commercial flying and around 50 times more than rail.

For tourism, this means a small group of very frequent, often wealthy, travelers drives a large share of the sector’s climate impact.

5. Cruise tourism: floating cities with outsized footprints

Cruise ships are effectively small cities running on heavy fuel oil. Their emissions per passenger-km can be several times higher than flying.

• A classic study of cruises to and from New Zealand found emission factors ranging from 250 to 2,200 g CO₂ per passenger-km, with a weighted mean of about 390 g CO₂/pkm—roughly 4× the average emissions of commercial passenger aviation.

• Analysis by the International Council on Clean Transportation found that even the most efficient modern cruise ships emit about 250 g CO₂ per passenger-km, still far higher than typical flights.

Cruise vessels also consume huge amounts of energy for their “hotel” functions—heating, cooling, lighting, pools, restaurants, entertainment. One comparison estimated that the energy used per passenger-night onboard can be an order of magnitude higher than in land-based hotels.

While cruises are a smaller slice of total tourism volume than flights or car trips, their per-person climate impact is among the worst options available.

6. Ground transportation: cars, coaches, and trains

For many trips—especially domestic or regional travel—people mostly move by road.

Per-passenger emissions vary widely by mode:

• An average petrol car emits about 170 g of CO₂ per km; if there’s only one person in the vehicle, that’s 170 g per passenger-km.

• Coaches and full buses can be much more efficient, often closer to or below aviation’s 90 g CO₂/pkm, because emissions are shared across many passengers.

• Electric or high-speed rail powered by low-carbon electricity can be extremely efficient—one analysis gives 4 g CO₂ per passenger-km for Eurostar services, about 3% of a comparable short-haul flight on the same route.

Back in 2005, UNWTO’s breakdown suggested:

• Cars alone were responsible for about 32% of tourism CO₂ emissions,

• “Other transport” (including buses and rail) for another 3%.

Even today, with aviation’s share growing, road travel remains a major contributor, especially for domestic tourism, road trips, and destinations where flying is less affordable but long car journeys are common.

7. Accommodation: the carbon cost of a hotel night

Once travelers arrive, where they stay also matters.

Several datasets shed light on hotel emissions:

• UK government (DEFRA) data suggests staying in a typical hotel in the UK results in about 10.4 kg CO₂-equivalent per room-night.

• A French calculator that aggregates European data estimates average footprints ranging from ~4.7 kg CO₂e per night in unclassified hotels to ~17.1 kg CO₂e per night in 5-star properties.

• A global review of low-carbon hotels found dramatic variation, from about 4.7 kg CO₂ per room-night at eco-focused hotels in Costa Rica to over 150 kg CO₂ per room-night in some luxury resorts in the Maldives, where energy is often supplied by diesel generators and air-conditioning demand is high.

One industry estimate suggests that hotels are responsible for roughly 1% of global CO₂ emissions, when you add up all lodging worldwide.

In the 2005 tourism breakdown, accommodation accounted for about 21% of tourism’s CO₂, a share that is still used as a ballpark estimate in climate-tourism literature.

The key drivers are:

• Energy intensity of buildings (insulation, design, efficiency).

• Energy mix (fossil fuels vs renewable electricity and heat).

• Occupancy and operation (laundry practices, pool heating, food waste, etc.).

8. Food, activities, and tourism infrastructure

8.1 Food and beverages

Tourists tend to eat more, drink more, and waste more than at home, often choosing emissions-heavy options like beef and imported seafood.

Sustainable Travel International estimates that tourism as a whole accounts for around 8% of global emissions, and about 10% of tourism’s own emissions are tied to food and beverages—through agricultural production, transport, refrigeration, and cooking.

A recent study in the Journal of Sustainable Tourism found that simply putting vegetarian dishes at the top of hotel menus significantly increased plant-based orders, hinting at how behavioral “nudges” in hospitality can cut food-related emissions without banning meat.

8.2 Activities, shopping, and construction

Other pieces of tourism’s footprint include:

• Attractions and activities (ski lifts, theme parks, golf courses, scuba operations, adventure tours).

• Shopping and souvenirs, which embed manufacturing and shipping emissions.

• Infrastructure and construction, notably resorts, second homes, airports, and cruise terminals.

Life-cycle assessments of coastal tourism areas and hotel complexes show that building and maintaining infrastructure can rival or exceed the operational emissions over time, particularly when concrete, steel, and large pools or landscaped grounds are involved.

While these categories are harder to quantify precisely, they are included in the 8–9% global figure for tourism emissions produced by Lenzen and Sun’s work.

9. How tourism demand, low-cost airlines, and mass tourism amplify emissions

Why has tourism’s carbon footprint grown so quickly?

9.1 Rising incomes and a growing global middle class

UN Tourism’s modelling for its transport emissions report highlights:

• Strong links between GDP per capita, population growth, and tourism demand;

• Projections that international arrivals could reach 1.8 billion by 2030, and domestic tourism volumes much higher.

As more households cross income thresholds where travel becomes affordable, tourism demand accelerates—a classic example of “luxury emissions.”

9.2 Low-cost carriers and cheap long-haul travel

The expansion of low-cost carriers and budget long-haul flights has:

• Dramatically reduced the cost of air travel, especially in Europe and parts of Asia.

• Encouraged short city-break trips by air, which are particularly carbon-intensive per day of vacation because the flight dominates the footprint.

Policy choices also matter: fuel for international aviation often remains untaxed or lightly taxed, and many governments promote tourism as an export-earning sector without fully accounting for the climate impacts.

9.3 Mass tourism and over-tourism

Cities like Barcelona, Venice, Amsterdam and popular islands are examples of mass tourism straining local infrastructure and ecosystems:

• News reports from Spain highlight record tourism numbers in 2025, with nearly 96.8 million foreign visitors and tensions over housing affordability as short-term rentals proliferate.

While over-tourism is usually framed as a social or cultural problem, the sheer density of visitors also means dense emissions, especially when cruise ships and flights concentrate on a few hotspots.

9.4 Tourism and global climate budgets

A systematic review of tourism and climate change mitigation warns that if left unchecked, tourism could consume up to 40% of the remaining global carbon budget compatible with 1.5°C warming.

Sun’s 2024 analysis similarly frames tourism as a sector whose emissions growth is incompatible with Paris Agreement trajectories, unless both volume and intensity of travel change significantly.

10. Tourism emissions before, during, and after COVID: key numbers

To understand the “volume” side of the equation, it helps to look at how international tourism flows changed around the pandemic.

Table 2 – International tourist arrivals and recovery relative to 2019

Tourism emissions are not perfectly proportional to these numbers (because trip length, transport mode, and distance differ), but the broad pattern mirrors this trajectory:

• Steady increase to 2019,

• Extraordinary collapse in 2020–2021,

• Rapid rebound by 2023–2025, returning the sector to a path of rising emissions.

11. Tourism, home-country emissions, and climate fairness

Tourism emissions are deeply uneven:

• High-income countries generate most of the tourism demand and spending, and thus most tourism emissions, even when those emissions occur in other countries’ airspace or territory.

• Emerging economies such as China, India, and Brazil are rapidly growing as sources of both domestic and outbound tourism emissions.

The 2024 “Drivers of global tourism carbon emissions” paper emphasizes that “fair contributions” to mitigation need to account for equality, responsibility, and capability. It argues that uniform percentage cuts in tourism demand across all countries would be unfair, because rich countries and frequent flyers currently account for a disproportionate share of emissions.

In other words: who travels, how often, and how far matters more than simply how many tourists exist.

12. Mitigation: how can tourism reduce its climate impact?

Bringing tourism into line with the Paris Agreement requires both technological decarbonization and changes in travel behavior and policy.

12.1 Decarbonizing aviation

The aviation industry, represented by the International Air Transport Association (IATA), has adopted a net-zero emissions target for 2050, relying heavily on:

• Sustainable aviation fuels (SAF)

• More efficient aircraft and operations

• Market-based measures and offsets.

Reality checks:

• IATA expects global SAF production to double in 2025 to about 2 million tonnes, but that would still supply only ~0.7% of total airline fuel demand.

• A later Reuters interview with IATA’s director general warned that shortages of new, efficient aircraft and SAF are already jeopardizing the net-zero goal, as older planes remain in service longer.

Independent analyses suggest that operational changes could cut a large chunk of emissions even before new fuels are widespread:

• A 2026 study reported that optimizing load factors, reducing premium seating, and favoring efficient aircraft could halve aviation emissions without reducing total passenger travel, by eliminating some of the worst inefficiencies.

From a tourism standpoint, the implications are:

• Short-haul flights where good rail alternatives exist are low-hanging fruit for reduction or modal shift.

• Premium cabins and private jets, which have outsized emissions per passenger, are prime candidates for regulation or pricing.

12.2 Cleaner cruise and shipping

Mitigation options for cruise tourism include:

• Switching from heavy fuel oil to cleaner fuels (LNG, methanol, and eventually e-fuels), though each has trade-offs.

• Shore power so ships can plug into cleaner electricity at port instead of running engines.

• Efficiency measures: slower steaming, hull design improvements, and smarter routing.

However, given the extreme per-passenger emissions of cruises, many climate researchers view this as a sector where demand reduction—fewer or cleaner cruises—is as important as technological fixes.

12.3 Greening hotels and resorts

Hotels are more “decarbonizable” than airplanes:

• Energy-efficiency retrofits (LED lighting, insulation, smart thermostats).

• Electrification of heating and hot water (heat pumps).

• Switching to renewable electricity, either on-site solar or via the grid.

Examples from China’s tourism sector show this in action: projects like Beijing Daxing International Airport using geothermal and ice-storage systems to cut emissions by thousands of tonnes per year, and resort chains installing solar and wind power.

Because hotels are long-lived assets, standards for new builds—on energy performance, materials, and location—are critical to avoid locking in high emissions for decades.

12.4 Food, waste, and nudging behavior

On the operations side, hotels and restaurants can:

• Reduce food waste using data and AI (for example, adjusting purchasing and preparation), an approach already being trialed by major hotel groups.

• Shift menus toward lower-carbon choices (more plant-based options, smaller portions of high-impact meats). Experiments show that simply reordering menus can materially change what guests choose.

• Improve recycling and waste treatment, especially in isolated destinations where landfill leakage is a concern.

These changes are small relative to aviation but add up across millions of guests and meals and can be implemented quickly.

12.5 Smarter destinations and digital tools

Digital technologies can help tourism grow “better” rather than simply “more”:

• AI-driven route optimization reduces fuel burn in aviation by improving flight planning and avoiding contrail-forming conditions, which have a significant warming effect.

• Destinations can use data to spread visitors across seasons and locations, avoiding peak congestion and distributing economic benefits more evenly.

• Platforms can label low-carbon travel options, as some Chinese booking sites now do for hotels and transport.

These tools don’t replace structural decarbonization, but they help bend the curve while bigger infrastructure transitions are underway.

12.6 Policy: from voluntary pledges to binding frameworks

On the policy front:

• UN Tourism’s “Transforming Tourism for Climate Action” initiative, presented at the UN climate talks, calls for aligning tourism with 1.5°C pathways and notes that transport-related CO₂ emissions from tourism were projected to rise by 25% between 2016 and 2030 under current policies.

• Proposals include carbon pricing, aviation fuel taxation, mandatory emissions reporting for tourism businesses, and integrating tourism into national climate strategies.

Academic reviews consistently conclude that current mitigation measures fall short, and that achieving Paris-aligned emissions trajectories will likely require:

• Capping or reducing total aviation demand, especially frequent flying;

• Strong regulation and investment to shift transport and accommodation to low-carbon energy;

• Addressing equity, so high-emitting travelers shoulder more of the burden.

13. Tourism, climate risk, and long-term economics

It’s easy to frame tourism only as a cause of climate change, but it’s also highly vulnerable to climate impacts:

• Rising temperatures and extreme heat make many traditional summer destinations uncomfortable or unsafe.

• Sea-level rise threatens beaches, coastal resorts, and low-lying islands.

• Wildfires, floods, and storms can devastate tourist regions and infrastructure.

From a purely economic standpoint, the sector must now weigh:

1. Short-term gains from continued volume growth against

2. Long-term risks: physical damage, reputational harm, and potential future policies that could sharply increase the cost of high-carbon travel.

For example, industry projections presented at aviation conferences suggest that meeting net-zero goals could require trillions of dollars of investment, largely in SAF and new aircraft, with ticket prices rising substantially by 2050 if costs are passed to consumers.

That means business-as-usual tourism growth is not just a climate risk, but an economic gamble.

14. What a lower-carbon tourism system could look like

Putting all this together, a climate-aligned future for tourism likely includes:

• Fewer but longer trips:

  • Instead of multiple short city-break flights, people take one longer holiday, staying longer at the destination.

  • This spreads the flight emissions over more days and spending.

• Mode shifting for short and medium distances:

  • High-speed rail and electric buses becoming the default where available.

  • Policies and pricing that make flying the last resort, not the first.

• Electrified, efficient accommodations:

  • New hotels and resorts designed as near-zero-carbon buildings, with renewables and efficient systems.

  • Older stock progressively retrofitted.

• Richer experiences, not just higher volumes:

  • Destinations focusing on value per visitor rather than headcount.

  • Policies to limit over-tourism and cruise dependence where local ecosystems and communities are stressed.

• Fairer distribution of emissions:

  • Stronger constraints—and higher costs—on ultra-emitting activities like private jets and luxury cruises.

  • Climate finance and technology transfer to help tourism-dependent developing countries decarbonize.

15. Conclusion: travel in an age of carbon budgets

Global tourism is not a marginal footnote in climate math. At nearly one-tenth of global greenhouse gas emissions, with a footprint that was growing faster than the world economy before COVID, it is a core part of the climate problem—and therefore the solution.

The pandemic offered a stark demonstration: when travel stopped, emissions fell sharply. But the rebound since 2022 shows that without structural change, tourism will simply return to—and then exceed—its previous emissions trajectory.

The good news is that many of the tools to decarbonize tourism already exist:

• Cleaner aircraft and fuels, smarter operations, and rail alternatives.

• Efficient, renewable-powered buildings and sustainable food systems.

• Policy frameworks from UN Tourism, the Intergovernmental Panel on Climate Change (IPCC), and national governments that outline 1.5°C-aligned pathways.

The harder part is choosing to use them at the speed and scale required, and accepting that truly sustainable travel may mean:

• Flying less often,

• Paying more when we do fly, and

• Designing tourism systems that prioritize climate and community health alongside economic growth.

In the coming decades, the question won’t be whether we travel, but how—and how much—in a world that is finally treating carbon as a finite resource.