Climate change "mitigation impossible" without transport

Article Published 15 Sep 2010 Last modified 11 May 2021
4 min read
As the source of substantial and rapidly growing greenhouse gas emissions, transport must clearly be part of a global agreement to mitigate climate change.


As the source of substantial and rapidly growing greenhouse gas emissions, transport must clearly be part of a global agreement to mitigate climate change. In its current form, however, the Kyoto Protocol ignores the international maritime and aviation sectors. The omission is perhaps not surprising — after all, setting up a system to allocate international transport’s emissions to individual countries is no easy task. But it is a significant flaw, since the two sectors together account for around a quarter of all transport emissions.

Despite its shortcomings, the COP-15 climate summit in December 2009 succeeded in bringing transport closer to climate mitigation discussions. Almost all participants recognised that international transport emissions need to be addressed as part of broader efforts to mitigate climate change. Consequently, the relevant United Nations bodies — the International Maritime Organization and the International Civil Aviation Organization — were asked to work towards an agreement on reducing emissions.

The EU is acting on transport emissions

The European Union is likewise adamant about tackling emissions from all forms of transport. Commission President Jose Manuel Barroso has made it clear that decarbonising transport is a priority for his second term. Similarly, the new Commissioner for Climate Action, Connie Hedegaard, has stressed the importance of developing a low-carbon strategy for transport.

Climate mitigation has thus moved to the heart of transport policy and indeed to the heart of EU policy. Scientists talk about the need for a 50 % reduction in global greenhouse gas emissions by 2050 and 80–95 % reductions on the part of developed countries. And transport will clearly have to contribute. Today the sector accounts for around one quarter of all EU emissions, so we can only meet these long-term emissions targets if we reduce emissions from the transport sector.

Emission trading for transport?

The scale of transport’s GHG emissions clearly demands a policy response. Transport is generally not exposed to international competition, meaning that a trip from Paris to Poznan cannot be replaced by one from Singapore to Sidney. There is therefore no real risk of ‘carbon leakage’ with emissions that are regulated in Europe simply moving abroad. This, in principle, makes transport a good candidate for emission trading as a means to regulate emissions.

Two other criteria should also be met before embarking on a trading scheme. First, the number of operators in the market must be limited in order to make the allocation of allowances manageable. Aviation meets this criterion and emission trading will start in coming years. Maritime transport could also meet this criterion but verification is more difficult because ships can carry fuel for longer periods of time than planes. Rail is already covered by emission trading as the electricity used is bought from a sector under emission trading. Road transport, however, cannot meet the ‘limited number of operators’ criterion as each driver is essentially an operator.

Second, the carbon price should be high enough to induce a change in behaviour. The current carbon prices would add less than 1 ¢ per kilometre to the cost of driving a car (less than 4 ¢ per litre of fuel). Compared to present fuel taxes it is insignificant and therefore unlikely to have any impact on behaviour.

Cleaner cars but more of them

Some issues have already been addressed. New passenger cars have been put on a trajectory towards emissions of 95 g CO2/km by 2020 — almost a 50 per cent cut compared to 1990. Unfortunately traffic levels are growing at around the same rate as average emissions are projected to fall, meaning that the net effect may still be far from what we need.

Initiatives exist to include vans and, with a longer time perspective, trucks into the emissions target. But without complementary measures there is still a risk that most improvements will be offset by the growth in traffic. Indeed, more efficient vehicles may lower transport costs in the long run, thereby increasing the demand for transport (a phenomenon known as ‘the rebound effect’). This process is already apparent in the airline industry. Half a century ago few could afford a vacation in Thailand but now it is available to a broad segment of society.

The changes that are needed are thus profound. Transport is an integral element of our lives and changes therefore affect us all. Small incremental adjustments may not be enough to deliver a shift away from a carbon-based paradigm. Instead, addressing the climate challenge requires us to create a vision of what the transport system should be like by the middle of the century, so that it can be debated. The process of establishing a new Common Transport Policy for the EU is essentially about creating this vision and then filling it out with policies that can deliver its goals. This will be the real challenge in creating a pathway towards a de-carbonised transport sector.