Climate and Transport

• Road transport is the largest contributor to CO₂ emissions in the UNECE region.
• The COVID-19 pandemic caused a sharp decline in CO₂ emissions in 2020, followed by a partial rebound in 2021 and beyond, though emissions remain below pre-pandemic levels.
• Transitioning to zero-emission vehicles is essential for reducing road transport emissions and achieving SDG 13.

CO₂ Emissions from Transport in the UNECE Region

CO₂ emissions from the transport sector remain a significant challenge for achieving climate goals. The advancement of SDG 13 (Climate Action) relies heavily on reducing emissions in this sector. Road transport consistently accounts for the vast majority of CO₂ emissions in the UNECE region, as shown in Figure 1, which captures data over the past three decades. Rail transport, though a much smaller contributor to CO₂ emissions, has remained relatively stable over this period. Rail offers a more energy-efficient and lower-emission alternative for both passenger and freight transport. Shipping, covering all water-borne transport including inland waterway and maritime transport, contributes only a minor share of total emissions.

A sharp decline in emissions was observed in 2020, coinciding with the global COVID-19 pandemic. The rebound seen in 2021 and beyond reflects a partial recovery in transport activity, though emissions levels remain below their pre-pandemic peak.

Figure 1 Inland transport GHG emissions in UNECE region, 1990-2023

Zero-Emission Passenger Cars

Considering that road transport is the largest contributor to CO₂ emissions in the UNECE region, transitioning to zero-emission vehicles is critical to meeting climate goals and reducing the sector’s environmental impact.

Tracking new registrations of passenger cars by fuel type provides valuable insights into the carbon intensity of the vehicle fleet in the years to come. This data supports SDG 13 by monitoring the transition from fossil fuel dependence to more sustainable energy sources in the transport sector. Policymakers and stakeholders can assess the effectiveness of emission-reduction initiatives by monitoring the uptake of zero-emission passenger cars. These insights also help shape policies and infrastructure development to facilitate the adoption of clean-energy vehicles.

The UNECE region has witnessed a sharp increase in new electric passenger car registrations over the past decade. Germany has emerged as a frontrunner in this movement, with over 450,000 new electric vehicle (EV) registrations in 2022 alone. However, when it comes to the proportion of EVs within the total passenger car fleet, Norway leads the way. Known for its aggressive and long-standing EV policies, Norway boasts a remarkable 20% of its passenger car fleet being electric, solidifying its position as a global leader in the transition to electric mobility.

Several other UNECE countries have also made significant strides in EV adoption. Yet, despite these advances, the proportion of EVs in the total passenger car fleets across most UNECE countries remains relatively small. Outside of Norway, the vast majority of UNECE countries (with available data) have less than 5% of their fleets made up of electric vehicles. In particular, countries like Türkiye, Cyprus, and Poland currently have low proportions of EVs, underscoring the ongoing challenge of achieving widespread adoption across the region.

Figure 2 Proportion of electric passenger cars in the total fleet of passenger cars, 2022

The Impact of Vehicle Weight on CO2 emissions

The weight of new vehicles significantly affects their CO₂ emissions. Heavier cars generally require more energy for propulsion, leading to higher emissions. However, this relationship is evolving, particularly with the rise of electric vehicles, whose batteries contribute substantial weight but result in lower CO2 emissions. Data from the years 2013 and 2022 across selected European countries show a trend of decreasing CO2 emissions despite an increase in vehicle weight. This can be attributed to several factors, including the weight of batteries in electric vehicles and overall improvements in the fuel efficiency in newer vehicle models.  

Figure 3 New passenger car average weight against new passenger car average CO2 emissions

Technological improvements have also played a significant role in reducing energy consumption and, consequently, CO2 emissions in Germany. Despite a continuous increase in goods transport performance over time, the energy consumption per unit of goods transported (measured in tonne-kilometres) is decreasing. This trend indicates that the energy efficiency in the transport of goods is improving.

Figure 4 Energy efficiency in goods transport in Germany, 2005-2021