The latest estimates from the International Energy Agency (IEA) indicate that the transport sector contributed nearly 23% of global CO2 emissions from fuel combustion in 2012. Transport, with an average annual growth rate of 2.0% from 1990-2012, is among the fastest growing sectors of CO2 emissions from fuel combustion. 

Tracking emissions trends in the transport sector (in the context of economy-wide emissions) is an essential step in defining possible transport components of Intended Nationally Determined Contributions (INDCs) from UNFCCC parties, and in helping to determine required contributions from transport to establish and achieve national and global mitigation targets.  Yet,tracking global averages is of limited use to countries who are developing their INDCs to support the upcoming COP21 meeting in Paris, and therefore we must have a clearer understanding of transport emissions trends and differentiation atnational levels to take effective actions to reduce global transport sector emissions and achieve an IPCC-recommended 2-degree scenario (2DS). 

To inform the discussion on the contribution of transport to CO2 emissions and also the role that transport should play in mitigation strategies – in particular,INDCs –the Partnership on Sustainable Low Carbon Transport (SLoCaT) has developed the SLoCaT Analysis of Transport Emission Trends  to illustrate national and regional trends in transport related CO2 emissions. 

Some of the highlights of our analysis:

• In 2012 transport was the largest energy consuming sector in 40% of countries worldwide, and in most remaining countries, transport is the second largest energy consuming sector.
• In 2012, nearly two thirds of countries had a transport sector share of total emissions from fuel combustion greater than the global average of 23%, and the share of countries exceeding the global average is increasing over time.
• Transport sector emissions growth in Annex I countries averaged 0.5% from 1990 to 2012(with negative growth of 0.8% from 2008 – 2012), and non-Annex I countries averaged 4.8% (with growth of 5.5% from 2008-2012).
• It is expected that by 2016 or 2017 transport emissions from non-Annex I ocuntries will be larger than those from Annex I countries.
• About half of countries worldwide have experienced either high or very high growth (i.e. more than 3% or 5%, respectively), in the 1990-2012 period, however, from 2008-2012, 33% of countries worldwide experienced either zero or negative growth.
• Growth rates of EU-28 and OECD Americas, which were largely similar for 1990-2000 started to differ for 2000-2008 and show a marked difference for 2008-2012 (i.e.the EU-28 showssubstantial negative growth (-2.2%) while OECD Americas shows a very marginal decrease (-0.2%).
• Within the non-Annex 1 countries the fastest growth at a regional levelis in China(if considered as a separate region).
• Crucially, growth in transport emissions can be decoupled to some extent from economic growth.Annex I Parties in particular have limited transport emissions growth to well below GDP growth rates, and even non-Annex I Parties have also kept transport growth below GDP growth over this 12-year period (albeit by a much narrower margin.
• Globally, nearly 82% of transport emissions are generated from countries (both developed and developing) which have committed to official (conditional or unconditional) economy-wide emission reduction targets (whether absolute or as a reduction in energy intensity) under the UNFCCC process.
• While transport growth rates in Annex I countries with targets have reduced over the years, for non-Annex I countries with targets, transport emission growth rates have actually increased over the 2008-2012 period
• Although the United States topped the rankingsin absolute amounts of transport CO2 emissions for both 1990 and 2012, developing countries are emerging as large emitters in transport sector (e.g. China, India, Brazil, Mexico, Indonesia) and several European countries (e.g. France, Italy and United Kingdom) are dropping out of the top 10 out largest transport related emitters in absolute terms.
• Thetop 10 transport CO2 emitters in 2012 contributed to 53% of total global transport CO2 emissions.
• Countries which have consistently kept gasoline prices above US$1/liter over period 2000 to 2012 (e.g. Japan, Netherlands, Uruguay) show clear reductions in transport emissions growth, and countries with gasoline prices above US$0.7/liter (e.g. many OECD countries) show only a marginal increase in transport emissions growth. However, for countries that have kept gasoline prices artificially low due to fuel subsidies, transport CO2 emissions have grown at a rapid rateduring the 2000-2012 period.
• Average transport CO2 emissions per capita in 2012 in non-Annex I countries amounted to only 18% of the average emissions per capitain AnnexI countries; however, the average annual growth rate in transport CO2/capita in Non-Annex I countries from 1990-2012 was around 3%, while in Annex I countries it was around 0.1% during the same period.

Maximizing mitigation ambition requires optimizing contributions from transport. TheSLoCaT Analysis of Transport Emission Trends gives a broadpicture of trends in transport CO2 emission share, growth, and absolute and per-capita emissions among Annex I and non-Annex I countries. A crucial observation within this analysis is the large differentiation among transport emissions trends between individual regions and countries, which underscores the necessity to taking a heterogeneous approach to tackling current and future transport sector emissions worldwide.

This variation among countries leads to a number of key implications for integrating transport in economy-wide emission strategies.  First, a considerable number of countries will need to scale up transport mitigation strategies because transport contributes a large share of overall emissions.  Second, transport emissions are growing faster than average fuel combustion related-CO2, making it likely that it will become a more substantive problem in the future if not tackled in the near term.  Third, many countries that currently have very low transport emissions per capitaare showing significant growth in this sector, and thus will have to take additional action to keep transport emissions in check in the coming decades.  Fourth, a decoupling of transport emissions and economic growth is possible, as already demonstrated by many Annex I countries as well as a number of non-Annex I countries.  Finally, there is a very clear linkage between fuel prices and transport CO2 emissions, which emphasizes the need to phase out fossil fuel subsidies and initiate carbon pricing in the transport sector.

This analysis of historic trends can be complemented by a growing body of transport mitigation potential studies across a wide range of UNFCCC Parties, which can help to define a suitable set of transport sector implementation strategies.According to the IEA, a halving in GHG emissions from transport is projected to be feasible by 2050 and will be necessary to realize a 2DS, since cross-sectoral burden sharing is feasible only to a limited extent.  The 2DS is estimated to represent cumulative investments of USD 445 trillion and represent a cumulative investment and operating saving of USD 70 trillion over 2010-2030; thus, Parties that incorporate low carbon strategies into national transport strategies can achieve not only emissions reductions and development benefits, but also financial gains.

To stay within an IPCC-recommended 2DS,Parties to the Convention must think critically about sectorial approaches in the process of defining INDCs that will allow them to raise pre-2020 ambition and establish post-2020 targets. 

For a more detailed assessment of trends in national transport emissions click here.