Environment and Sustainability

Environment and Sustainability

Biophilic Design in Airport Terminals: The Operational Case

Airport Intelligence Series Biophilic Design in Airport Terminals: The Operational Case April 2026 5 min read Airports are, by design, among the most stressful environments humans regularly move through. They are large, loud, and structurally engineered for throughput rather than comfort. The clock is always running. Which is precisely why biophilic design has found such fertile ground here. Studies across neuroscience and environmental psychology consistently show that exposure to natural elements lowers heart rates, reduces blood pressure, improves cognitive function, and shortens perceived recovery time from stress. The business case is direct. Calmer passengers dwell longer, spend more at retail and food and beverage, and form more positive associations with the airport brand. There is also a wayfinding dimension. Large terminals are inherently disorienting. Distinctive natural installations can function as memorable landmarks in a way that signage alone cannot. Passengers anchor their spatial memory to the garden, not the gate number. But it is not without challenges. The hostile indoor environment is the starting point. Terminals are usually deep-plan buildings where natural light does not reach everywhere. They run under continuous mechanical ventilation Airside zones near boarding gates open repeatedly onto the tarmac, creating thermal stress on living plants and posing MEP challenges for consistent growing conditions. The birds is another challenge, which is more serious in airport context. Bird strikes cost the aviation industry over $1.2 billion annually in repairs and downtime. The cruel irony: naturalistic internal planting is highly attractive to the birds that airport operators are simultaneously mandated to exclude from aircraft. Inside the terminal, bird droppings can enter ventilation systems and nesting material can damage HVAC infrastructure. Living plant installations require dedicated horticultural staff and irrigation systems maintained around 18-to-24-hour operational schedules, and plant replacement cycles managed without disrupting passenger flow or generating risks. THE CHANGI LESSON: WHAT SUSTAINED EXCELLENCE LOOKS LIKE If there is one airport in the world that has consistently excelled in this department, it is Singapore Changi. Not because of Jewel, but because of what sits behind it: a maintenance infrastructure that most airports don’t have and haven’t thought to build. Changi has more than 500,000 plants across its four main terminals, covering some 250 species. It produces approximately 3,000 plants a month in its own nursery. To tend to all of this, the airport employs a dedicated team of horticulturalists. LESSON 1 Build the Supply Chain Before You Need It   Most airports treat plant maintenance as a procurement function: when something fails, a contractor is called. Changi treats it as a production function. The CAG Plant Nursery — a three-hectare facility nurturing 50 species. It is responsible for the propagation, cultivation, and distribution of display plants, including unique cultivars named after the airport itself: the Bougainvillea ‘Changi Airport’ and the Dendrobium ‘Singapore Changi Airport.’ The nursery also functions as a controlled acclimatization environment where plants spend time growing under conditions that approximate what they will face inside the terminal. Without this, every replacement is a procurement event: slow, expensive, and often resulting in plants that fail again within months. LESSON 2  Treat Species Selection as an Engineering Decision When Changi was populating Jewel, the procurement process alone took nearly three years. Sourcing more than 2,000 trees and palms and over 100,000 shrubs across 120 species from around the world required nine months of procurement and a further two years of local nursery conditioning. Many trees had to be pruned to fit shipping containers before being nursed back to health on arrival. The key criterion throughout was not aesthetic preference. Each species was evaluated against its ability to thrive within the complex, given its specific light levels, temperature, and humidity conditions. Horticulture expertise at the design stage is what makes this possible. LESSON 3  Close the Waste Loop The CAG horticulture team actively diverts waste from its nursery and gardens to be used as compost. The programme is expanding to include horticultural waste from the gardens and from trees along Airport Boulevard. This matters on two levels. Practically, it reduces the operational cost of waste disposal for a high-volume plant programme. Strategically, it closes the loop — the landscape produces its own inputs. For airports pursuing LEED this is a measurable circular economy outcome. LESSON 4  Curate Continuously Biophilic design in a terminal is not a one-time capital decision. It is a continuously curated programme — and data is what makes curation disciplined rather than intuitive. The horticulture team uses data analytics to understand what visitors are responding to, using that information to guide the design of seasonal displays. THE COMMITMENT BEHIND THE CANOPY The Changi model is always not directly replicable. Especially because of its scale, its government backing, and Singapore’s national identity as a City in a Garden create conditions that are difficult to transplant. But its underlying logic is entirely transferable, and it comes down to institutional decisions rather than financial ones. Building a sustainable supply chain, treating species selection as an engineering specification and designing for the waste loop from day one. Are all good implementable lessons from Changi. Nature in the terminal is worth pursuing. The evidence on the benefits is strong. But the forest doesn’t maintain itself. And in an airport, nothing is low-maintenance, unless one plans for it from the beginning.  Share Share Share

Environment and Sustainability

Sustainable Aviation Fuel: How prepared are we to meet industry targets?

Airport Intelligence Series Sustainable Aviation Fuel: How prepared are we to meet industry targets? Co-authored by Debayan Sen and Ira Gupta August 2025 4 min read Introduction Airlines around the globe are committing to aggressive decarbonisation goals and to achieve net zero emissions by 2050. IATA estimates that Sustainable Aviation Fuel (SAF) is expected to be a key driver and could contribute ~65% of the reduction in emissions needed by the aviation sector to meet net zero ambitions. In Europe, policy mandates are accelerating SAF adoption. The European Union’s ReFuelEU Aviation initiative has come into force on 1st January 2025 and requires a minimum SAF blend of 2%. This will rise to 6% by 2030, 20% by 2035, and 70% by 2050. Meanwhile, the United Kingdom has set its own SAF mandate which also commenced with a 2% blend in early 2025. This will gradually ramp up with at least 10% SAF by 2030 and a roadmap towards net zero aviation by 2050. In 2024, global SAF production doubled in comparison to 2023 reaching 1.3 billion litres. However, this only accounted for 0.3% of the total global jet fuel production. The projected share of SAF for 2025 is 0.7% [1]. There is a long way to go before meeting industry targets and will need a significant ramp in production to ~7 billion litres annually.   There are 11 certified pathways to make feedstock for SAF and nearly half of the total market share for SAF is dominated by five large firms – Neste (Finland), Total Energies (France), World Energy LLC (UK), Eni (Italy) and OMV (Austria) [2]. India’s foray into SAF has been fairly recent compared to its global counterparts. A number of test flights were undertaken by airlines in 2018 and 2022. India is aiming for a 1 per cent SAF blend in ATF by 2027. The target will increase to 2 per cent in 2028 and reach 5 per cent by 2030 [3]. Challenges to adoption  Regulatory framework: National mandates and regulations should be aligned with IATA timelines. Periodic review of progress is required at intermediate milestones.    Increase in production infrastructure:  To meet 2050 targets, IATA estimates that 3000- 6500 renewable fuel plants will be needed. In the short-term, existing refineries can be used to co-process up to 5% of approved renewable feedstocks alongside the crude oil streams.   Pricing:  SAF prices can be 2 to 10 times the conventional jet fuel depending on production volumes and the quantum of public subsidies [4]. This remains a key barrier. In the UK, a price cap of £1.50 (~US$2) for a single air fare has been introduced to cover the cost of SAF blending. However, in price-sensitive markets like India such a move could negatively impact passenger demand as well as airline profitability since aviation fuel can account for nearly 40% of operational costs.    Supply reliability: Maintaining a consistent and affordable supply of SAF is necessary for wide-scale adoption. Airports may not need significant infrastructure upgrades but rather the focus must be on reliable supply chains, controlling logistics costs and quality checks.   Skilled Manpower: SAF production incorporates highly technical processes that require specialized expertise in biofuel technology, chemical engineering and large-scale industrial processes. Fast-growing aviation markets such as India will require further investment in training and upskilling manpower. Way forward We believe the long-term outlook for SAF production is positive. At a macro-level, meeting short-term milestones may be challenging without new production infrastructure.  Interim solutions could include use of existing refineries to co-process approved renewable feedstock. In India, the newly signed MoU between IndianOil and Air India to supply ISCC-CORSIA-certified SAF—produced from used cooking oil, with an expected annual output of 35,000 tonnes [5], is a step towards early commercial partnerships. This venture will use repurposed infrastructure to kick-start real supply chains, reinforce demand certainty, and build momentum toward blending targets.  A pragmatic incentive scheme can also stimulate the supply chain and provide price stability in the initial years. The global nature of the aviation industry means that both mature and emerging markets need to work side by side to meet industry targets. In recent times, SAF funds such as the Sustainable Aviation Fuel Financing Alliance (SAFFA) have emerged as a new category of sustainability-related investment vehicles in aviation. The airlines in India will need to get into the act and make bets to drive SAF investments. We understand that this is hard in an industry with thin margins. The risk can be shared by other players in the aviation ecosystem, such as companies that are looking beyond a target Internal Rate of Return to meet a broader range of sustainable, climate-conscious outcomes. [1]https://www.iata.org and https://www.iata.org/en/pressroom/2025-releases/2025-06-01-02/ [2]https://www.marketsandmarkets.com/ResearchInsight/sustainable-aviation-fuel-market.asp[3]https://www.constructionworld.in/transport-infrastructure/aviation-and-airport-infra/india-sets-saf-blending-targets-for-international-flights/[4]DOE (USA) https://www.energy.gov/eere/bioenergy/sustainable-aviation-fuel-grand-challenge[5]Indian Oil signs MoU with Air India for supply of sustainable aviation fuel – The Economic Times  Share Share Share

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