Data story: Global travel emissions, offsetting rates, and sustainable tourism adoption trends

Why It Matters

Tourism accounts for roughly 8 to 11 percent of global greenhouse gas emissions when indirect supply chain effects are included, yet fewer than 3 percent of airline passengers voluntarily offset their flights (UNWTO, 2025). The sector rebounded to 96 percent of pre-pandemic passenger volumes by the end of 2024 (ICAO, 2025), and the International Energy Agency projects aviation CO2 emissions will reach 1.1 gigatons by 2030 under current policies, a 25 percent increase over 2019 levels (IEA, 2024). At the same time, traveler surveys consistently show that over 70 percent of respondents say sustainability influences their booking decisions, yet the gap between stated intention and actual purchasing behavior remains stubbornly wide (Booking.com, 2025). This disconnect between demand signals and market outcomes makes travel emissions one of the most consequential and under-addressed sustainability challenges. Tracking the data on emissions trajectories, offset uptake, eco-certification, and sustainable tourism adoption reveals where progress is genuine, where greenwashing persists, and where intervention can have the greatest impact.

Key Concepts

Aviation carbon intensity measures CO2 emissions per revenue passenger kilometer (RPK). The global fleet average stood at approximately 88 grams of CO2 per RPK in 2024, down from 95 g/RPK in 2019 thanks to newer aircraft deliveries and higher load factors (IATA, 2025). However, absolute emissions have grown because passenger volumes have increased faster than efficiency gains.

Carbon offsetting in the travel context refers to purchasing carbon credits to compensate for trip-related emissions. Offset options range from low-cost avoidance credits (renewable energy, cookstove projects) to higher-cost removal credits (direct air capture, biochar). Uptake remains low: Chooose, a leading aviation offset integration platform, reports that when offset options are presented at booking, only 1 to 5 percent of passengers opt in, and the rate drops further when the option requires an additional click or page (Chooose, 2025).

Sustainable accommodation certification encompasses schemes such as the Global Sustainable Tourism Council (GSTC) standards, Green Key, EarthCheck, and Travelife. As of early 2026, the GSTC has recognized 39 certification bodies, and approximately 180,000 accommodation properties worldwide hold some form of recognized sustainability certification, representing roughly 5 percent of global hotel inventory (GSTC, 2026).

Scope 3 travel emissions represent business and leisure trips within a company's or destination's carbon footprint. The GHG Protocol's Category 6 (business travel) and Category 7 (employee commuting) are increasingly scrutinized under CSRD and SEC disclosure frameworks, pushing corporate travel managers to collect granular emissions data and set reduction targets.

What's Working and What Isn't

What's working. Several data points suggest genuine progress in specific segments. Sustainable aviation fuel (SAF) production reached 1.5 million metric tons in 2025, triple the 2023 volume, though it still represents less than 0.5 percent of total jet fuel consumption (IATA, 2025). Rail is gaining modal share on short-haul routes in Europe: Eurostar reported record ridership of 19 million passengers in 2025, and several European countries have banned or restricted domestic flights on routes where a train journey of under 2.5 hours exists (European Commission, 2025). In the accommodation sector, Hilton reported a 52 percent reduction in carbon intensity per occupied room since 2008 through its LightStay program, and Accor committed to a 46 percent absolute Scope 1 and 2 emissions reduction by 2030 from a 2019 baseline validated by SBTi (Hilton, 2025; Accor, 2025). Destination-level action is also accelerating: Palau, Costa Rica, and Slovenia have embedded sustainability metrics into national tourism strategies, and Palau's Pristine Paradise Environmental Fee generates over $10 million annually for conservation while managing visitor volumes (Palau Visitors Authority, 2024).

Corporate travel policies are evolving as well. A 2025 survey by the Global Business Travel Association found that 64 percent of managed travel programs now include an emissions tracking component, up from 38 percent in 2022, and 29 percent have implemented per-trip carbon budgets or internal carbon pricing for travel decisions (GBTA, 2025).

What isn't working. Despite these bright spots, the aggregate data show that emissions are rising, not falling. Global aviation CO2 emissions reached an estimated 920 million metric tons in 2024, exceeding the 2019 level of 905 Mt for the first time since the pandemic (IEA, 2025). Voluntary offset rates remain negligible at scale: the total volume of aviation-linked offset retirements in 2024 was approximately 12 million tons, covering barely 1.3 percent of the sector's emissions (AlliedOffsets, 2025). CORSIA, the UN's Carbon Offsetting and Reduction Scheme for International Aviation, entered its first mandatory phase in 2024, but its baseline methodology and credit eligibility criteria have drawn criticism for weak ambition, with some analyses suggesting CORSIA will offset only 3 to 5 percent of international aviation growth emissions through 2030 (Transport & Environment, 2025).

Greenwashing in sustainable tourism remains pervasive. A 2025 European Commission study found that 53 percent of environmental claims made by hotels and tour operators in the EU were vague, misleading, or unsubstantiated, and 40 percent lacked any supporting evidence (European Commission, 2025). The proliferation of self-declared "eco" labels without third-party verification confuses consumers and undermines credible certification schemes.

Cruise industry emissions present an additional challenge. A single large cruise ship can emit as much particulate matter per day as a million cars, and the sector's absolute emissions grew 10 percent from 2023 to 2024 as fleet expansion outpaced efficiency improvements (International Council on Clean Transportation, 2025).

Key Players

Established Leaders

• UNWTO (UN Tourism) — Global tourism policy body driving the Glasgow Declaration on Climate Action in Tourism, with 900+ signatories committing to halve tourism emissions by 2030.
• IATA — Represents 300+ airlines and coordinates the industry's Net Zero 2050 commitment, SAF procurement targets, and CORSIA implementation.
• Global Sustainable Tourism Council (GSTC) — Sets baseline sustainability standards for destinations and accommodations, recognizing 39 certification bodies globally.
• Booking.com — Largest online travel agency, displaying Travel Sustainable badges on 500,000+ properties and publishing annual Sustainable Travel Reports.

Emerging Startups

• Chooose — API-based platform integrating carbon offsetting and SAF contributions into airline and corporate travel booking flows. Partners with 30+ airlines.
• Thrust Carbon — Provides granular emissions calculation and reduction tools for corporate travel management companies and TMCs.
• Greengage — Offers real-time carbon tracking for hotel operations with IoT sensor integration and automated sustainability reporting.
• Tomorrow's Air — Community-funded carbon removal subscription model focused on travel-related emissions, directing funds to direct air capture projects.

Key Investors/Funders

• European Investment Bank — Committed over $1 billion to sustainable transport and SAF production facilities since 2023.
• Breakthrough Energy Ventures — Invested in multiple SAF startups including LanzaJet and Infinium.
• World Bank Group — Funds sustainable tourism development programs in 40+ developing countries through IFC tourism finance facilities.

Examples

Scandinavian Airlines (SAS) SAF blending mandate. SAS has committed to a 50 percent SAF blend on all domestic Scandinavian flights by 2030, supported by Sweden's national SAF blending mandate which increased from 0.8 percent to 6 percent in 2025. SAS reported that SAF usage reduced lifecycle emissions by approximately 80 percent compared with conventional jet fuel, and the airline's cost premium for SAF was partially passed through to passengers via a transparent "green fare" surcharge averaging $4 to $12 per ticket (SAS, 2025).

Intrepid Travel's decarbonization program. Australian adventure tour operator Intrepid Travel became the first global tour operator to achieve SBTi validation for its near-term targets. The company measures emissions across all 1,000+ itineraries, has eliminated optional internal flights from 80 percent of tours, and invested $2 million in carbon removal projects in 2024. Intrepid reports a 28 percent reduction in per-trip emissions since 2018 while growing revenue by 45 percent (Intrepid Travel, 2025).

Costa Rica's certification and conservation model. Costa Rica's Certification for Sustainable Tourism (CST) program, managed by the Costa Rican Tourism Board, has certified over 400 hotels, tour operators, and car rental agencies. The country generates over 60 percent of its electricity from renewable sources and channels tourism fees into a payment for ecosystem services (PES) program that has reforested over 60,000 hectares since 1997. Tourism contributed $4.8 billion to Costa Rica's GDP in 2024 while the country maintained 30 percent of its territory under protected status (ICT Costa Rica, 2025).

Marriott International's sustainable operations scale. Marriott's Serve 360 program targets a 50 percent reduction in water intensity and a 30 percent reduction in carbon intensity by 2025 from a 2016 baseline across 8,800+ properties. The company reported achieving a 33 percent carbon intensity reduction by end of 2024, deployed on-site solar at 450 properties, and eliminated single-use toiletry bottles across its full portfolio, preventing an estimated 500 million small plastic bottles from entering waste streams annually (Marriott, 2025).

Action Checklist

• Calculate your organization's travel emissions using a tool aligned with the GHG Protocol (Category 6 for business travel) and set a reduction target consistent with SBTi or equivalent framework.
• Implement a travel policy hierarchy that prioritizes virtual meetings first, rail for trips under 4 hours, direct flights over connections, and economy class over business or first class.
• Integrate SAF procurement into corporate travel contracts by requesting SAF certificates or book-and-claim allocations from airline partners.
• Require third-party certified sustainable accommodations (GSTC-recognized certifications) in travel booking platforms and preferred hotel programs.
• Offset residual travel emissions using high-integrity carbon removal credits verified under ICVCM Core Carbon Principles rather than low-cost avoidance credits alone.
• Track and disclose travel emissions at the trip, department, and organizational level using automated data feeds from travel management companies.
• Engage employees through transparent communication about travel emissions data, personal carbon budgets, and incentives for lower-carbon trip choices.

FAQ

Why are voluntary offset rates for air travel so low? Multiple factors contribute. Most airlines present offsetting as an opt-in add-on at the end of the booking process, where decision fatigue is high and price sensitivity peaks. Consumers also express skepticism about whether offsets actually deliver climate benefits, a concern amplified by media coverage of low-quality carbon credit projects. Research by Chooose (2025) shows that offset uptake increases five-fold (from 1 percent to 5 percent) when the option is integrated into the fare selection step rather than presented as an afterthought. Default-on offset models (where passengers must opt out) have achieved uptake rates above 70 percent in trials but face regulatory and consumer-rights challenges.

How much does sustainable aviation fuel actually reduce emissions? SAF produced from waste oils, agricultural residues, or municipal solid waste can reduce lifecycle CO2 emissions by 60 to 80 percent compared with conventional jet fuel, depending on feedstock and production pathway (IATA, 2025). Power-to-liquid SAF produced using renewable electricity and captured CO2 (e-fuels) can achieve reductions above 90 percent but remains 3 to 6 times more expensive than fossil jet fuel. The primary constraint is supply: SAF represented less than 0.5 percent of global jet fuel consumption in 2025, and scaling production to meet IATA's target of 10 percent by 2030 requires approximately $100 billion in new refinery investment.

Are eco-certifications for hotels meaningful or just marketing? It depends on the certification body. GSTC-recognized certifications (Green Key, EarthCheck, Travelife, Green Globe) require third-party audits, measurable performance indicators, and continuous improvement. These schemes have demonstrated measurable reductions in energy, water, and waste intensity at certified properties. However, self-declared "eco-friendly" labels without independent verification are common and often lack substance. The European Commission's 2025 study on green claims found that over half of hotel sustainability claims in the EU could not be substantiated. Travelers and corporate buyers should specifically look for GSTC-recognized logos rather than generic green branding.

What is CORSIA and will it meaningfully reduce aviation emissions? CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) is an ICAO mechanism requiring airlines to offset CO2 emissions growth above a baseline on international routes. Its first mandatory compliance phase began in 2024 and covers states representing over 75 percent of international aviation activity. However, critics argue that CORSIA's baseline (set at 85 percent of 2019 emissions) is lenient, its credit eligibility criteria permit low-quality offsets, and it only addresses growth emissions rather than the sector's absolute footprint. Transport & Environment (2025) estimates that CORSIA will abate only 3 to 5 percent of international aviation growth emissions through 2030. CORSIA is best understood as a floor, not a ceiling, for aviation climate action.

How can individual travelers reduce their travel carbon footprint? The most impactful actions are to fly less frequently and choose shorter destinations reachable by rail or road; when flying, choose direct routes in economy class (per-passenger emissions in business class are roughly 3 times higher due to seat pitch and weight allocation); select GSTC-certified accommodations; and offset residual emissions through high-quality carbon removal projects. A round-trip economy flight from London to New York generates approximately 1.0 to 1.2 tonnes of CO2 per passenger, roughly equivalent to 10 percent of the average European's annual carbon footprint.

Sources

• UNWTO. (2025). Tourism and Climate Change: Global Emissions Assessment and Policy Recommendations. United Nations World Tourism Organization.
• ICAO. (2025). Annual Report of the Council: Air Transport Statistics and Trends. International Civil Aviation Organization.
• IEA. (2024). Aviation Tracking Report: CO2 Emissions Projections to 2030. International Energy Agency.
• Booking.com. (2025). Sustainable Travel Report 2025: Consumer Attitudes and Booking Behavior. Booking Holdings.
• IATA. (2025). Aviation Carbon Intensity and Sustainable Aviation Fuel Progress Report. International Air Transport Association.
• Chooose. (2025). State of Aviation Carbon Offsetting: Uptake Rates, Integration Models, and Consumer Behavior. Chooose.
• GSTC. (2026). Global Sustainable Tourism Council Annual Review: Certification Bodies and Property Coverage. GSTC.
• European Commission. (2025). Screening of Websites for Greenwashing: Tourism and Hospitality Sector. Directorate-General for Justice and Consumers.
• Transport & Environment. (2025). CORSIA Assessment: Ambition, Eligibility, and Projected Abatement. Transport & Environment.
• GBTA. (2025). Business Travel Sustainability Barometer: Emissions Tracking and Carbon Budget Adoption. Global Business Travel Association.
• AlliedOffsets. (2025). Aviation-Linked Carbon Credit Retirements: Annual Volume Analysis. AlliedOffsets.
• International Council on Clean Transportation. (2025). Cruise Ship Emissions Inventory: Fleet-Level Trends 2019-2024. ICCT.
• Hilton. (2025). ESG Report: LightStay Program Results and Carbon Intensity Metrics. Hilton Worldwide.
• Accor. (2025). Climate Strategy and SBTi Validated Targets Progress Report. Accor Group.
• SAS. (2025). Sustainability Report: SAF Blending Progress and Green Fare Program. Scandinavian Airlines.
• Intrepid Travel. (2025). Impact Report: SBTi Targets, Per-Trip Emissions, and Carbon Removal Investments. Intrepid Group.
• ICT Costa Rica. (2025). Sustainable Tourism in Costa Rica: CST Program and Economic Contribution. Instituto Costarricense de Turismo.
• Marriott. (2025). Serve 360 Report: Environmental Performance and Sustainable Operations. Marriott International.