Climate

Figure 10 shows direct GHG emission trends over time for different transport modes in the EU-27 (including emissions from international bunkers) and projections until 2050. Other pollutants with a climate effect are covered in the air pollutants section. Upstream emissions, such as those associated with electricity generation or fossil fuel extraction and manufacturing are not included in this analysis. Downstream emissions are also omitted, such as those from the end-of-life and recycling of vehicles and their components.

Transport GHG emissions are expressed in million tonnes of carbon dioxide equivalent (MtCO₂e). These peaked at approximately 1,142MtCO₂e in 2007 and fell after the 2009 recession before reaching a second peak in 2019 at 1,103MtCO₂e. Emissions then fell sharply to 899MtCO₂e in 2020 during the COVID-19 pandemic, a drop of 18.5% compared to the previous year. In 2023, they rose again (by 15.6% compared to 2020) to approximately 1,039MtCO₂e. This was still 6.3MtCO₂e lower than 2022. Overall, transport GHG emissions were 25.3% higher in 2023 compared with 1990.

Transport’s share of total GHG emissions from the EU-27 has risen steadily, from 16.5% in 1990 to 28.6% in 2019. It accounted for approximately 31% of all EU-27 GHG emissions in 2023, 2.1 percentage points higher than in 2022.  

Projected emissions in Figure 10 correspond to those reported by Member States under Article 18 of the Regulation on the Governance of the Energy Union. Through this regulation, each Member State developed an integrated national energy and climate plan according to the ‘with additional measures’ (WAM) scenario. This, as further explained in the Annex, includes policies and measures adopted or implemented at the time of reporting and all planned measures (which may not reflect the latest developments at the EU level). These projections suggest Europe’s transport sector will still be emitting 325MtCO₂e in 2050, with navigation as the major contributor (36.3%), followed by road transport (32.7%), aviation (29.6%) and rail (0.6%). The relative contribution of transport (including international bunkers) to overall GHG emissions in the EU-27 is expected to decrease slightly from 31% in 2023 to 24.5% in 2050.

Road transport

Road transport GHG emissions in the EU-27 come almost entirely from light- and heavy-duty vehicles. Powered two-wheelers and other road transport modes are responsible for less than 1% of total transport emissions. Emissions from road transport reached 757MtCO₂e in 2023, up 22% since 1990.  

Emissions from light-duty vehicles (i.e. cars and vans in Figure 10) reached approximately 544MtCO₂e in 2023, accounting for about 52.4% of all transport GHG emissions. This share has remained essentially constant over the last 33 years, with an average of 53% and standard deviation of 1.1%. Overall, GHG emissions from light-duty vehicles increased by 21.6% in 2023 compared to 1990. Rising sales of new zero-emission vehicles, combined with improved energy efficiency of new vehicles and more use of biofuels (both promoted by EU legislation (Regulation 2019/631 and Directives 98/70/EC and 2023/2413)), have been more than offset by the increase in passenger car transport activity. This is discussed further in the section on passenger transport activity (see Figure 1).  

The EU’s CO₂ emission performance standards are key policies for the gradual reduction of road transport CO₂ emissions. More stringent standards for new cars and vans were adopted in 2023. Notably, this includes a fleet-wide complete CO₂ emission reduction target for new cars and vans by 2035 (0 gCO₂/km at the tailpipe). Despite manufacturers’ significant progress in decarbonising new vehicle fleets, further emission reductions are necessary to meet future targets.

Heavy-duty vehicles emitted approximately 203MtCO₂e in 2023, 20% of all transport GHG emissions. Overall, GHG emissions from heavy-duty vehicles have increased by 24.1% since 1990. These vehicles emitted almost the same amount of GHG as the navigation and aviation sectors combined (both national and international), which totalled 275MtCO₂e in 2023. The increase in GHG emissions from heavy-duty vehicles in the 1990-2023 period was primarily driven by growth in freight transport activity and an increase in the share of road freight transport, as discussed in the section on freight transport activity (see Figure 3). This was only partly offset by lower energy consumption per tonne-km and the uptake of biofuels.

CO₂ emission performance standards for new heavy-duty vehicles were tightened further in May 2024. These include a fleet-wide 90% CO₂ emission reduction target by 2040 and a provision to have all new urban buses with zero CO₂ tailpipe emissions by 2035. Further emissions reductions will be needed to achieve these new targets.  

Powered two-wheelers (mopeds and motorcycles) accounted for 9MtCO₂e  of GHG emissions in 2023, 30% lower than domestic aviation. Emissions oscillated during 1990 to 2023 and have increased 7% overall since 1990. These represented just 0.9% of the GHG emissions from transport in 2023.

Overall, road transport emissions in 2023 totalled approximately 757MtCO₂e, representing 72.9% of all transport emissions and 22.6% of all EU-27 GHG emissions (including international bunkers). According to projections, emissions from the road transport sector will reach 546MtCO₂e in 2030 and 106MtCO₂e in 2050, corresponding to reductions of 27.9% and 86%, respectively, compared to 2023.

The Energy Performance of Buildings Directive has been revised. Among other things, this supports the transition towards the electrification of road transport and aims to strengthen the development of charging infrastructure for electric vehicles. It includes, for example, provisions on pre-cabling for new and renovated buildings (to enable the installation of charging points at a later stage with minimal effort) and stricter requirements on the number of recharging points which must be available in both residential and non-residential buildings. To support vehicle-to-grid integration, recharging points will have to allow smart charging and bi-directional charging, where appropriate. This complements the Alternative Fuel Infrastructure Regulation (AFIR), which has set binding, harmonised targets across all EU Member States for the deployment of publicly accessible electric vehicle recharging infrastructure since April 2024. For example, AFIR requires infrastructure along major transport corridors (the TEN-T core network) to be deployed at regular intervals (e.g. electric fast chargers every 60km on major roads) and encourages smart and bidirectional recharging, ensuring interoperability and accessibility.

In addition to the measures already discussed, the sector is expected to be covered by ETS2, addressing CO₂ emissions from fuel combustion in buildings, passenger and freight road transport and small industry. The ETS2 cap is expected to bring emissions down by 42% by 2030 compared to 2005 levels (regarding the total emissions from buildings, road transport and others). It will also address the social impacts of carbon pricing by allocating revenues from emissions trading to climate action, with a focus on vulnerable households and micro-enterprises.

Waterborne transport

Combined EU-27 GHG emissions from domestic and international navigation (including inland navigation) reached 139MtCO₂e in 2023, an increase of 12% since 1990. This trend follows a similar trajectory to total transport emissions (see Figure 10). Waterborne transport accounted for around 13% of total transport emissions in 2023, a share that has remained relatively constant over 1990 to 2023. International navigation accounted for approximately seven times the emissions from domestic navigation in the same year. Notably, emissions from domestic navigation fell by around 28.2% to 17MtCO₂e from 1990 to 2023.  

Regulation (EU) 2023/957 was adopted in 2023 and amended the monitoring, reporting and verification (MRV) system originally established by Regulation (EU) 2015/757. As of 2024, shipping companies must monitor and report emissions of not only CO₂ but also methane (CH₄) and N₂O, both of which contribute significantly to the sector’s GHG emissions. From 2025, the regulation’s scope expands to include smaller general cargo ships with gross tonnage between 400 and 5,000, as well as offshore ships of 400 gross tonnage and above. Additionally, as of 2024 the EU ETS applies to CO₂ emissions from ships of 5,000 gross tonnage and above which call at or depart from ports within the European Economic Area (EEA), regardless of the vessel’s flag. This system covers 100% of the emissions produced while at berth within EEA ports, or travelling within the EEA, and 50% of emissions from voyages starting or ending outside the EEA. From 2026, emissions of CH₄ and N₂O will also be covered by the EU ETS framework. The revised ETS Directive also requires revenues generated from auctioning maritime allowances to be directed towards decarbonising the maritime sector, including climate action and transformation of the energy system. These revenues are intended to support climate impact reduction in shipping and to help address social challenges linked to carbon pricing.

Finally, the FuelEU Maritime Regulation (Regulation (EU) 2023/1805), applied from 1 January 2025, aims to increase the uptake of low- and zero-carbon fuels in maritime transport. It requires the GHG intensity (measured in gCO₂e/MJ) of energy used on board ships of and above 5,000 gross tonnage calling at EU ports to be reduced progressively. Articles 8 (monitoring plan) and 9 (modifications to the monitoring plan) are excluded. GHG intensity must fall by at least 2% in 2025, by 6% in 2030, and by 80% in 2050, following 5-year increments (certain exemptions apply until 2030). Reductions will be estimated from a reference value (91.16gCO₂e/MJ) based on data reported under the MRV system for 2020. The regulation also mandates the use of onshore power supply (OPS) or alternative zero-emission technologies while at berth, as discussed further in the section on energy infrastructure.  

Projections introduced at the start of this section suggest emissions from waterborne transport will reach 145MtCO₂e in 2030 and 118MtCO₂e in 2050. This corresponds to variations of 4.4% (-6.5%) and -15% (-23.9%), respectively, compared to 2023 (2019).

Aviation

Aviation has seen the largest relative increase in GHG emissions among transport subsectors. GHG emissions from aviation peaked at around 148MtCO₂e in 2019, a rise of about 123.7% since 1990. This was largely driven by international flights emitting 8.9 times more than domestic ones. Aviation accounted for 13% of total transport GHG emissions in 2019, up by approximately five percentage points since 1990. Although aviation emissions dropped to 64MtCO₂e in 2020 due to the disruption of the COVID-19 pandemic, they rebounded strongly to 136MtCO₂e by 2023. This was more than double the emission levels in 1990 and represented 13.1% of all transport emissions.  

Notably, aviation CO₂ emissions within the EEA are covered by the EU ETS (specific provisions exist for outermost regions). Switzerland’s proprietary system is linked to the EU ETS, while the UK system is independent. Emissions above the aviation cap must therefore be compensated by emission reductions in other EU ETS sectors, such that the overall ETS cap is respected.  

Aviation also contributes to global warming through mechanisms beyond CO₂ emissions that are normally labelled as non-CO₂ effects. The total average climate impact of aviation is estimated to lie between two and four times that associated to CO₂ impact. This high variability results from the uncertainty of quantifying non-CO₂ effects being higher than those of CO₂ emissions. Non-CO₂ effects include, among others, the emission of climate-forcing pollutants and the formation of stable contrails in ice supersaturated regions that can absorb and reflect infrared radiation. Mitigating these contrails and their effect could be done quickly and cost-effectively. EU ETS rules for the aviation sector have been revised recently in Directive (EU) 2023/958. This implements a monitoring, reporting and verification (MRV) system for non-CO₂ effects in aviation through Implementing Regulation (EU) 2024/2493. The EC will submit a report based on the MRV by 2027. If deemed appropriate, and after an impact assessment, the EC will produce a proposal to address non-CO₂ effects by 2028.  

In addition to the EU ETS, in the context of the Fit for 55 policy package, the ReFuelEU Aviation Regulation aims to gradually increase the uptake of sustainable aviation fuels (SAF). These can reduce aircraft GHG emissions by variable amounts, depending on several factors. The regulation requires a progressive increase in the supply of SAF at all EU airports, starting from 2% in 2025 and reaching 70% by 2050. From 2030, 1.2% of the fuel supply should be synthetic aviation fuel, increasing to at least 35% by 2050. The revised EU ETS Directive also supports additional resources to electrify aviation and actions to reduce the overall climate impacts. Indeed, the revised directive commits Member States to using all ETS revenues for climate action, energy transformation and addressing the social challenges of carbon pricing.  

GHG emissions from international and domestic aviation are projected to be around 133MtCO₂e in 2030 and 96MtCO₂e in 2050, i.e. variations of -2.4% (-10.2%) and -29.2% (-34.9%) compared to 2023 (2019), respectively.

Rail

The rail sector has the lowest absolute GHG emissions (see Figure 10) with approximately 3MtCO₂e in 2023. This is consistent with a highly electrified sector and the fact that rail emissions in the GHG emission inventory are only related to fossil fuel consumption. Falling diesel consumption led to a 73.7% reduction in direct emissions from 1990 to 2023 (Figure 7), despite a 39.9% increase in rail passenger transport activity (Figure 1), a stable situation for freight activity (Figure 3) and no significant increase in electricity consumption (Figure 7). Overall, rail accounted for 0.3% of the direct emissions from transport in the EU-27 in 2023.

Methane and nitrous oxide emissions

The following paragraphs consider the historical and projected emissions of methane (CH₄) and nitrous oxide (N₂O). These potent GHGs have respective global warming potentials of 28 and 265 times that of CO₂ in a 100-year timeframe. In 2023, CH₄ and N₂O from transport respectively accounted for approximately 0.15% and 0.91% of overall transport GHG emissions and 0.41% and 5.68% of the overall CH₄ and N₂O emissions in the EU-27, as measured in MtCO₂e.  

CH₄ emissions also affect air pollution as they contribute to ground level (tropospheric) ozone formation. Equally, N₂O has been identified as the most significant anthropogenic contributor to stratospheric ozone layer depletion. Estimating the emissions of these compounds through conventional approaches is difficult. Hardly any emission standards exist across transport modes, except for the recently approved vehicle emissions and battery durability regulation (Euro 7)  which controls emissions and requires measurement during type-approval and in real-world tests. This implies there is a lack of good quality data when compared to more conventional compounds. Deriving accurate nitrous oxide emissions through fuel consumption is challenging because N₂O mostly forms in processes occurring in aftertreatment units, rather than by fuel use alone.  

CH₄ emissions from transport fell by 75.5% from 1990 to 2023 to 57.2Gg (or 57.2 kilotonne, kt) (Figure 11), mainly due to reduced emissions from passenger cars which fell from 173.9Gg in 1990 (a 74.5% share) to 23.3Gg in 2023 (40.8% share). This decrease can be largely attributed to the evolution of aftertreatment systems. Similar trends and reductions can be seen for other road transport categories over the same period.  

Interestingly, powered two-wheelers are a significant source of CH_4. Emissions equalled 7.7Gg in 2023, 1.5 times higher than those from heavy-duty vehicles, 7.7 times those of the whole aviation sector and comparable to emissions for international navigation. Emissions in the aviation sector remained generally stable between 1990 and 2023, averaging 1Gg with a standard deviation of 0.1Gg. International aviation emitted 3.5 times more than domestic aviation in 2023. 

CH₄ emissions have risen most in the navigation sector, reaching 17.5Gg in 2023, an increase of 70.5% compared to 1990. International navigation emits approximately 4.7 times more CH₄ than domestic navigation. As discussed in the energy section, this increase was partly due to an increased use of LNG and a shift in on-board machinery from steam turbines to reciprocating internal combustion engines.

Transport CH₄ emissions are expected to rise up to 2035 and then stabilise at a slightly lower level. This projection accounts for an expected increase in international navigation of 73.9% in 2030 and 608.7% in 2050 compared to 2023. At the same time, CH₄ emissions from road transport are expected to decrease by 77.8% by 2050 compared to 2023. Projections also foresee an increase of up to 4.78Gg in CH₄ emissions from domestic navigation by 2050.

N₂O emissions from transport increased from 1990 to a peak in 1998, dipped, then rose again up to 2019 to reach 37.4Gg (a 39.7% increase compared to 1990) (see Figure 12). Emissions were lower in 2023 at 35.7Gg, but this still represented a 33.3% increase from 1990.  

Road is the main transport source for this GHG and air pollutant with a dominant contribution to ozone depletion. Road accounts for 73.7% of all N₂O emissions from transport in 2023. Historical trends suggest passenger cars accounted for the first emission increase and heavy-duty vehicles for the second. In both cases, most N₂O emissions were associated with unwanted catalytic reactions occurring in aftertreatment systems.  

Systems vary in use depending on vehicle and engine technology (e.g. three-way catalysts (TWC), lean NOx traps (LNT) and selective catalytic reduction units (SCR)). NOx emissions from diesel engines have been mainly controlled through SCR systems in recent years. These are known to produce N₂O under certain operating conditions. This explains the recently apparent and ongoing increase in emissions, especially those seen from heavy-duty trucks. According to data reported in the inventories, heavy-duty trucks emitted 10.3Gg of N₂O in 2023, an increase of 121.4% compared with 1990. Research suggests that in real-world conditions N₂O emissions from heavy-duty trucks can be very high and contribute significantly to a vehicle’s overall CO₂e emissions. As mentioned previously, current methodologies used in GHG inventories may only partially capture this.  

A switch to internal combustion engines using carbon-neutral fuels or hydrogen will not necessarily address this issue. They will continue to emit substantial quantities of NOx that will need to be regulated through aftertreatment systems (very likely SCR units). Even if the direct combustion of such fuels does not release CO₂, significant quantities of climate-forcing gases could still be emitted in the process of controlling NOx.  

Moreover, if SCR units become common in other sectors, such as waterborne transport, where diesel technology is ubiquitous, N₂O emissions are likely to rise unless air emission standards contain safeguards. Indeed, in diesel engines equipped with SCR units, unless NOx, ammonia (NH₃) and N₂O emissions are regulated at the same time, systems could be calibrated to minimise the emission of some compounds at the expense of others. In the case of hydrogen (H₂) as an energy carrier, the gas itself can unintentionally slip into the atmosphere during combustion or in the production and transport processes. While H₂ is not a direct GHG, it affects atmospheric chemistry by impacting the lifetime of other GHGs, namely methane, ozone and water vapour. Ultimately, this has an overall climate warming effect.  

Waterborne transport was responsible for 13.5% of all N₂O emissions across all transport sectors in 2023, equating to 4.8Gg (83.0% of which was due to international transport). Emissions in the sector increased by 7.2% in the 1990-2023 period.  

Aviation contributed to 10.9% of overall N₂O emissions from transport in 2023, with 3.9Gg (90.1% coming from international transport). Emissions for the sector have risen by 99.2% in 1990-2023.  

N₂O emissions are expected to fall, mainly driven by a smaller contribution from road transport. Road transport N₂O emissions are projected to fall by 22% and 81.5% in 2030 and 2050, respectively, compared with 2023. A slight contraction in the contribution of both navigation and aviation is also expected, with a decrease of 25.6% and 23.2%, respectively, by 2050 compared with 2023.