Why going green isn’t easy: Real challenges of sustainable fuels

Despite global calls for decarbonisation and net-zero targets, the transition to sustainable fuels in aviation and maritime transport is off to a painfully slow start. In 2024, airlines consumed every available drop of Sustainable Aviation Fuel (SAF), yet it made up just 0.3% of global jet fuel use. The cruise industry faced a similar roadblock with Sustainable Marine Fuel (SMF), with negligible quantities available. The enthusiasm to adopt sustainable fuel is clear—but the reality is far more complicated.

Problem with supply

The aviation and cruise sectors have made bold sustainability commitments. Airlines are aiming for net zero by 2050, and cruise operators are also looking to reduce their environmental footprint. But there’s a catch: the sustainable fuel to meet these goals simply doesn’t exist in large enough quantities. This scarcity is more than a hiccup—it’s a bottleneck that threatens the viability of climate targets.

While SAF production doubled from 2023 to 2024, it still hit only 1.25 billion litres. To meet net-zero emissions goals by 2050, the International Air Transport Association (IATA) estimates the world will need 450 billion litres of SAF annually. That’s a 400-fold increase. To reach this scale, the world would need thousands of new renewable fuel plants—a monumental infrastructure build-out.

Why it’s hard to scale

Sustainable fuels aren’t produced from crude oil but from alternative feedstocks like used cooking oil, municipal waste, and fats. This makes them environmentally preferable, but also more complex to source and scale. Here are the core challenges:

• Limited production infrastructure: Sustainable fuels are expensive to produce, with facilities costing hundreds of millions to billions of dollars. Existing technology, such as HEFA (Hydroprocessed Esters and Fatty Acids), relies heavily on waste oils. While effective at small scales, it’s not easy—or cheap—to scale globally.

• Price tag: SAF currently costs between 3 to 10 times more than conventional jet fuel. Without meaningful subsidies or incentives, airlines and cruise lines simply can’t absorb those costs at scale.

• Feedstock competition: Waste oils and municipal waste are also used in other sectors—like agriculture and animal feed—creating competition that tightens supply and drives up costs.

• Regulatory mismatch: While many governments have set targets (such as 5–10% SAF by 2030), few have clear production roadmaps. With no global regulatory standard, airlines and cruise operators must navigate a patchwork of rules that make long-term planning difficult.

• Environmental tracking: Sustainable fuels are made and used across borders, which complicates emissions accounting. A cruise line might record direct emissions (Scope 1), while a port sees the same emissions as indirect (Scope 3). This ambiguity clouds reporting and weakens incentive structures.

The stakes for Travel & Tourism

Travel & Tourism accounted for 6.5% of global emissions in 2023, with transport responsible for 37% of that total. As demand for travel rebounds post-COVID and is projected to grow steadily through 2035, this emissions share will rise unless cleaner fuels become mainstream.

But the knock-on effects of a sustainable fuel shortage go beyond carbon. Prices could skyrocket, driving up the cost of flights and cruises. That’s a direct hit to the broader Travel & Tourism economy, which depends on affordability and accessibility. Moreover, travellers are increasingly aware of their carbon footprint. Businesses that can’t offer cleaner options risk falling behind as consumer expectations evolve.

What Can Be Done?

No single player can fix this. What’s needed is sector-wide, cross-industry collaboration. The World Travel & Tourism Council (WTTC) has outlined an engagement framework that assigns specific roles to companies in the value chain—whether they operate airlines, hotels, cruise ships, or travel agencies. These roles range from providing waste feedstock (like used cooking oil) to investing in sustainable fuel R&D or buying SAF certificates to offset travel emissions.

Some players are already leading. Jet2, a UK-based travel company, has invested in a SAF production plant expected to open in 2027. The Erawan Group, a hotel chain in Thailand, collects used cooking oil from its properties and supplies it to fuel producers. These early movers are laying the groundwork, but they can’t scale the supply chain alone.

1. Policy support: Governments must align mandates with production incentives. Tax credits, grants, and long-term purchase agreements will make or break the industry’s ability to scale.

2. Infrastructure investment: The sector needs thousands of new plants. Public-private partnerships, especially with institutional investors, are key.

3. Feedstock access: Travel & Tourism businesses can contribute by supplying waste oil and organic waste—an easy entry point into sustainable fuel support.

4. Unified advocacy: A fragmented regulatory landscape only adds friction. Global coordination can smooth standards, tracking, and accountability.

Sustainable fuels are not a nice-to-have. They’re essential for a decarbonised future in long-distance travel. But the road is steep, the scale is daunting, and the clock is ticking. Good intentions won’t get planes off the ground or ships out of port. Real investment, real policy change, and real coordination are needed to turn vision into volume. Going green was never going to be easy but failure is no longer an option. s