How Transport Shapes Global Energy Demand: Trends and Solutions

Transport is one of the largest and fastest-growing consumers of energy worldwide. It powers everything from daily commutes and freight deliveries to international shipping and air travel. Yet this essential sector comes with a steep environmental cost – it remains overwhelmingly dependent on fossil fuels, making it a leading source of greenhouse gas emissions. Understanding how transport shapes global energy demand is critical to tackling climate change, especially as urbanization accelerates across developing nations.

Transport’s growing energy footprint 🔗

The transport sector is a powerhouse of global energy consumption. According to the International Energy Agency (IEA), transport accounts for roughly 30% of total global energy demand and has contributed about 10% of the growth in total energy use since 2019. Within this sector, road transport dominates – it makes up nearly 90% of total domestic transport energy consumption. The remaining share is split among domestic aviation, shipping, and rail.

In advanced economies, passenger cars are the biggest energy users on the road, responsible for about 65% of transport energy demand, with trucks covering most of the rest. Buses, while consuming far less energy per unit, move people much more efficiently than private cars. In emerging economies, the picture shifts slightly – two-wheelers such as scooters and motorcycles play a larger role, accounting for around 5% of road energy demand, and heavy-duty trucks represent a higher share of total consumption.

The growth trajectory is uneven across regions. Non-OECD countries, home to roughly 80% of the world’s population, are driving the bulk of new transport energy demand. China and India, in particular, are seeing rapid increases in vehicle ownership and freight movement as their economies expand. China alone added the largest regional increment in transport energy consumption over recent decades, with heavy-duty vehicles leading the growth. India’s transport energy demand is also rising sharply as urbanization accelerates and the middle class grows.

Fossil fuels and emissions: the road transport challenge 🔗

Fossil fuels still reign supreme in the transport sector. Petroleum and other liquid fuels have historically supplied over 95% of transport energy, though that share is gradually declining as alternatives emerge. The REN21 Global Status Report 2025 highlights that between 2022 and 2023, fossil fuel use in the transport sector grew by 2.7%, while renewable energy consumption in transport increased by 6.7%. Still, renewables accounted for just 3.9% of total transport energy in 2022 – a modest increase from 2.9% a decade earlier.

Road transport is responsible for the majority of transport-related emissions. Approximately 1.3 billion passenger vehicles and 83 million commercial vehicles are on the road globally, and road transport accounts for 76% of total final energy use in the sector. The combustion of petrol and diesel in these vehicles produces massive quantities of CO₂, nitrogen oxides, and particulate matter, contributing to both climate change and urban air pollution.

Why the shift away from fossil fuels is slow 🔗

The Energy Institute notes that transitioning to lower-carbon fuels in transport remains difficult because current energy density requirements cannot be fully met by batteries and hydrogen in all applications. Heavy-duty trucking, long-haul aviation, and maritime shipping face particular challenges. Diesel and jet fuel pack enormous amounts of energy into a small volume – something that battery-electric solutions are only beginning to match for shorter-range applications.

That said, progress is real. Oil demand from road transport fell marginally in 2024, according to the IEA’s Global Energy Review 2025. This is partly due to the rapid growth of electric vehicles – EV sales displaced a meaningful share of the oil consumption that would otherwise have gone to passenger cars. Oil’s share of total energy demand dropped below 30% for the first time in 2024, half a century after it peaked at 46%.

The urbanization challenge 🔗

Rapid urbanization is a key driver of transport energy demand, especially in developing countries. As cities grow, so does the number of vehicles on the road, the distances people travel, and the volume of goods moved. This creates a cycle of increasing fuel consumption and emissions that is particularly visible in megacities.

Delhi: a case study in urban transport and energy 🔗

Delhi offers a striking example of how urbanization fuels transport energy demand. The city has over 7.9 million registered vehicles, with approximately 1,100 two-wheelers and 500 private cars added every day. The Centre for Science and Environment (CSE) reports that despite implementing one of the world’s largest CNG conversion programmes, leapfrogging to Bharat Stage VI emission standards, and beginning fleet electrification, vehicles remain the city’s top polluter among combustion sources. Emission inventory studies estimate that the transport sector contributes between 20% and 41% of Delhi’s PM2.5 pollution.

Several factors compound the problem. Urban sprawl has led to an 81.7% increase in average trip lengths, pushing more people toward private vehicles. The modal share of private vehicles in Delhi has risen from 38% to 49% over the past decade, while bus ridership has fallen. Congestion is severe – during peak hours, travel speeds drop dramatically, causing vehicles to idle and emit pollutants at rates many times higher than when moving freely. The transport sector’s contribution to Delhi’s NOx emissions stands at a staggering 81%, according to a 2018 inventory by TERI-ARAI.

Delhi’s situation reflects a broader pattern across South Asian and African cities, where motorization rates are climbing rapidly and public transport infrastructure struggles to keep pace.

The transport-pollution feedback loop in cities 🔗

In cities with high congestion and heavy reliance on fossil-fuelled vehicles, energy waste is enormous. Idling vehicles consume fuel without moving anyone or anything, generating heat, noise, and toxic emissions. The International Council on Clean Transportation (ICCT) has documented how real-world vehicle emissions in Delhi and surrounding areas often exceed laboratory testing limits, particularly for older diesel vehicles. This gap between official emission standards and on-road reality means that even regulated vehicles pollute more than expected.

The energy implications are significant. Every litre of fuel burned in congested traffic produces the same CO₂ as a litre burned on a free-flowing highway, but moves far fewer people and goods. Cities that fail to address congestion and public transport gaps are effectively wasting a substantial portion of their transport energy.

Future directions for energy reduction in transport 🔗

Reducing transport’s energy footprint requires action on multiple fronts – from vehicle technology and fuel sources to urban planning and public transit investment. Several strategies are already gaining momentum globally.

Electric vehicles: the leading solution for road transport 🔗

Electric vehicles have emerged as the most promising technology for decarbonising road transport. The IEA reports that global electric car sales surpassed 17 million in 2024, reaching a market share of over 20%. In the first quarter of 2025, sales rose another 35% year-on-year. China accounted for nearly 60% of global EV registrations, while Europe and the United States also saw strong adoption.

Research published in Communications Earth & Environment found that battery electric vehicles consistently have the lowest carbon footprints among passenger cars across multiple climate scenarios. On average, BEVs produce 32% to 47% fewer lifecycle emissions than hybrid vehicles, depending on the decarbonisation pathway of the electricity grid. As grids get cleaner, the advantage of EVs grows further.

Delhi’s own experience with electrification is instructive. The city deployed 595 electric buses between January and August 2024 alone, and its total fleet of electric buses reached approximately 1,970 by mid-2024. A study cited by the ICCT estimated that fully electrifying Delhi’s bus fleet could reduce total pollutant emissions by nearly 75%. Meanwhile, RMI’s Deliver Electric Delhi pilot showed that electric two-wheelers, three-wheelers, and four-wheelers could save 96%, 69%, and 74% in fuel costs respectively compared to their combustion-engine equivalents.

Hybrid vehicles and plug-in hybrids 🔗

Hybrid electric vehicles (HEVs) combine an internal combustion engine with an electric motor and battery. They offer immediate fuel savings and emission reductions without requiring charging infrastructure. Plug-in hybrids (PHEVs) go a step further by allowing drivers to run on electricity for short trips while retaining a petrol or diesel engine for longer distances.

However, research from the ICCT suggests that hybrids and plug-in hybrids provide only modest near-term emission reductions and lack the deep decarbonisation potential needed to meet Paris Agreement targets. A plug-in hybrid running partly on fossil fuel and partly on electricity produces roughly 30% fewer emissions than a standard petrol car – significant, but far short of the 70%+ reductions achievable with a full battery electric vehicle. Hybrids serve as a useful transitional technology, particularly in regions where charging infrastructure is still limited.

Low-carbon and alternative fuels 🔗

Beyond electrification, several alternative fuel pathways are being explored for segments of transport that are harder to electrify. Biofuels, including ethanol and biodiesel, are already blended into transport fuels in countries like Brazil and India. India is targeting 20% ethanol blending in petrol by 2025-26 to reduce vehicular emissions. The IEA’s Renewables 2024 report projects that biofuel use for road transport will continue growing, though its share of new renewable transport demand is shrinking as electric vehicles take a larger role.

Hydrogen fuel cells are another option, particularly for heavy-duty trucks and long-distance freight. However, the cost and infrastructure challenges remain substantial. E-fuels – synthetic fuels produced using renewable electricity – offer near-zero carbon emissions in theory, but cost parity with fossil fuels is not expected before 2050 at the earliest, according to the ICCT’s analysis.

For aviation and shipping, sustainable aviation fuels (SAF) and ammonia-based marine fuels are being developed. The European Parliament has mandated that 70% of jet fuels at EU airports must be sustainable by 2050, signalling the direction of regulatory pressure in these hard-to-abate sectors.

Public transport and urban planning 🔗

Technology alone cannot solve transport’s energy challenge. Shifting trips from private cars to buses, metros, cycling, and walking offers some of the most energy-efficient gains. A single bus carrying 50 passengers uses far less energy per person than 50 individual cars. Cities that invest in reliable, affordable, and well-integrated public transit systems can significantly reduce their transport energy footprint.

Delhi’s experience shows both the promise and the difficulty of this approach. Despite having nearly 7,700 buses and an extensive metro network, the city’s bus fleet remains inadequate – it has only about 45 buses per 100,000 population, well below the recommended benchmark of 60. Global leaders like London and Hong Kong have 80 to 90 buses per 100,000 residents. The Delhi Master Plan 2041 targets an 80:20 modal split in favour of public and shared transport, which would require a 1% annual shift away from private vehicle trips – an ambitious but necessary goal.

Compact, transit-oriented urban development that keeps homes close to workplaces can reduce travel distances and energy demand. Complementary measures like congestion pricing, parking management, and dedicated cycling infrastructure further encourage sustainable mobility choices.

The road ahead 🔗

Transport’s share of global energy consumption is unlikely to shrink on its own. Economic growth, rising incomes, and expanding trade will continue to push demand upward – particularly in developing economies where vehicle ownership is still far below developed-world levels. The challenge is to decouple this growth from fossil fuel consumption.

The solutions are clear: accelerate the adoption of electric vehicles across all vehicle segments, invest in public transport infrastructure, promote active mobility like walking and cycling, and develop low-carbon fuels for aviation and shipping. Policy support – through emission standards, fiscal incentives, and infrastructure investment – is essential to drive this transition at the required pace. Countries like India, with rapidly growing vehicle fleets and severe urban pollution, have the most to gain from acting decisively.

The good news is that momentum is building. Global EV sales are breaking records, renewable energy in transport is growing, and cities from Delhi to Shenzhen are deploying electric bus fleets at scale. The question is whether this momentum can be sustained and scaled fast enough to meet climate targets.

What do you think? Can cities in developing nations like India realistically shift from private vehicles to public transport fast enough to make a meaningful impact on energy demand? And as electric vehicles become more affordable, will they be enough on their own – or do we also need fundamental changes in how our cities are designed?

References

1. https://www.iea.org/reports/energy-efficiency-2025/transport
2. https://www.ren21.net/gsr-2025/sectors/transport/
3. https://www.energyinst.org/exploring-energy/topic/transport
4. https://www.iea.org/reports/global-energy-review-2025/global-trends
5. https://www.cseindia.org/mobility-crisis-is-behind-the-pollution-in-delhi-12455
6. https://theicct.org/wp-content/uploads/2024/08/ID-200-%E2%80%93-Delhi-RS_TRUE_Report_final.pdf
7. https://www.iea.org/energy-system/transport/electric-vehicles
8. https://www.nature.com/articles/s43247-025-02447-2
9. https://rmi.org/delhis-drive-towards-zero-emissions-deliveries/