More than 190 governments will meet in Santiago de Chile in December 2019 to agree how to make the objectives of the seminal 2015 Paris Climate Agreement a reality. More than ever, transport will be the focus of attention: it contributes nearly a quarter of man-made CO₂ and its share is still rising. Emma Latham-Jones talked to Pierpaolo Cazzola, a renowned expert on the links between energy and mobility, on what needs to happen to clean up transport.

Climate change is threatening the fundamentals for human life on earth

If we don’t prevent runaway climate change, what will be the effect on lives around the world?

Pierpaolo Cazzola: There is a broad consensus that human activities are causing changes in the climate that lead to major risks. These include droughts, rising sea levels that threaten low-lying regions, extreme and less predictable weather, and loss of biodiversity with potential impacts on human health, food security, water supply and economic development.

Transport is a major contributor to CO₂ emissions. How can we accelerate the transition to carbon-neutral mobility?

PC: That is a major undertaking. We can only achieve it through joint actions targeting several areas at the same time. And we must not forget to the human side in order to ensure that the transition is fair and equitable for everyone.

What are the main areas of action?

PC: I would say that there are six pillars upon which the decarbonisation of transport will have to build.

Firstly, we need to better manage travel demand. Policies that favour the development of compact cities with mixed-use buildings, for instance, reduce travel distances by cutting trip lengths and allowing more trip chaining.

Secondly, what experts call “modal shift”: Creating incentives for people to use transport modes that use less energy for the same service, such as public transport, and ensuring that it can be provided at affordable costs, promoting transit-oriented urban developments.

Thirdly, we need to maximise the capacity utilisation of vehicles. This reduces the energy needed to move each passenger or each unit of goods. Digital technologies can help to achieve this, and the right policy actions can do a lot to reduce the use of single-occupancy vehicles.

Fourthly, vehicles need to become much more energy-efficient. It is crucial that policies support the deployment of technologies that use less energy per kilometre. Policies must also seek to accelerate the transition towards technologies that produce zero emissions, in particular electric mobility.

Fifthly, the so-called energy vectors for transport need to be decarbonised. Energy vectors are the technologies that store energy and make it available for transport – e.g. liquid fuels, electricity, or hydrogen. If their generation cause emissions, not much is gained.

Finally, emissions from vehicle manufacturing and infrastructure construction also need to be minimised. This requires improvements in the design and usage phases to minimise the use of materials. It also requires greater recycling rates, along with the use of recycled inputs and a growing reliance on materials that can be manufactured through processes with low energy and greenhouse gas emission intensity.

Let me also add that the transition of transport towards zero emissions does not only need to go hand-in-hand with the decarbonisation of the rest of the energy system, but it can even contribute to foster it, through sector coupling. The latter creates mutual benefits by linking energy consuming sectors such as transport, housing or manufacturing with the power production when thinking about decarbonisation.

And how could that work?

PC: For example electric vehicles could be used as distributed energy storage for the power system. This in turn would help the energy providers to better deal with the supply imponderables associated with wind or solar power and thus encourage them to embrace renewable energy. Similar opportunities exist if hydrogen became part of the transport fuel mix. Digitalisation can be a powerful enabler for sector coupling – if policy creates the right conditions in time.

You mentioned improving energy efficiency of vehicles. But what’s the point if cars keep getting bigger and heavier?

PC: That’s a good point. We should also pay attention to resource efficiency. From a climate change perspective there is no point in making engines more energy efficient if the gain is used to propel heavier vehicles – emissions won’t fall. So the growth of vehicle size should be managed, as should the material requirements. A lot can be gained by choosing the powertrain technologies that is optimal for the use of the vehicle. Full electrification, for example, is best suited to vehicles that operate within a defined range and are used intensively, for instance taxis or urban buses.

Can we stop climate change without addressing transport emissions?

PC: Honestly, no.

So how much of an impact does the transport sector have on global carbon emissions?

PC: Transport is almost entirely dependent on oil and emits between 20 and 25% of the direct CO₂ emissions due to fuel combustion, which is the bulk of all emissions from greenhouse gases. Without immediate action, its share could reach 40% by 2030.

Transport’s contribution to CO₂ emissions is even larger from a life cycle perspective. We mustn’t overlook the emissions stemming from the production and distribution of transport fuels, resulting from the manufacturing of vehicles, and finally those caused by the construction of transport infrastructure. To give an example, this could be the cement used for roads, railways, ports and airports.

To put it bluntly, the Paris agreement can’t save the planet without the transport sector making major changes.

Will transport be a topic of discussion at COP25, the follow-up to the 2015 conference that resulted in the Paris Climate Agreement?

PC: Yes. The Chilean presidency of COP25 is organising a high-level event to bring together transport ministers at the conference in Santiago in December. This will be the first time transport ministers are invited to participate, and that is a significant, symbolic and important step. They have discussed transport and climate change at their own Summits, most recently in Leipzig in May 2019, where a group of ministers led by Sweden’s Thomas Eneroth and Chile’s Gloria Hutt agreed a statement on transport and climate change. But they have so far not been included in the wider climate change negotiations.

Do you think the debate around mitigation policies for transport is sufficiently grounded in empirical evidence?

PC: The policy debate on climate is well informed. In particular the Intergovernmental Panel on Climate Change (IPCC) has provided politicians with a solid factual basis for decision-making.

At the ITF, we also support policy action through the work of our Decarbonising Transport initiative. We provide quantitative evidence, through data analysis and advanced modelling that makes detailed projections on future transport activity and calculates the impact on transport CO₂ emissions, among many other things.

If we have the evidence, why isn’t transport already carbon-free?

PC: Liquid fuels for use in combustion engines have a high energy density. They are also cheap. Competing with these characteristics proved to be very hard. As a result, transport today relies on oil for 92% of its energy, and that makes the sector particularly hard to decarbonise. Other energy sources have only managed to establish themselves in some niches, for example electricity in rail.

But the negative side effects of fossil fuel use such as pollution were fairly evident right from the outset, weren’t they? Why did that not help to push alternatives?

PC: Problems that could have questioned the dominance of combustion technologies and fossil fuels, were addressed by treating the symptoms, rather than the causes. The local pollution generated by exhausts, for instance, was tackled by developing exhaust after-treatment technologies.

Now there are new constraints on fossil fuel use that won’t be so easily overcome, notably the CO₂ emissions from the combustion process. The availability of oil and our capacity to extract more capital-intensive oil resources fast enough will further contribute to diminishing benefits.

What opportunities are there for us to move away from fossil fuel use in transport?

PC: A good example is the combination of batteries electric motors and renewable electricity. Bioenergy presents another opportunity. Low-carbon biofuels are especially relevant for long-distance travel, where batteries are less well suited. Hydrogen could emerge as a climate-friendly transport fuel, or as an important element in the production of other climate-friendly fuels, for example ammonia or synthetic fuels. In parallel, digital technologies make it easier to share assets and use resources more efficiently – think about ride sharing.

So what exactly can decision-makers do at the national level to make the most of these opportunities?

PC: They should use fiscal levers such as carbon pricing and differentiated taxes on new vehicles. Distance-based charges will also be an important tool for steering mobility behaviour. Then, standards for fuel economy of vehicles and for the carbon-content of fuel are needed. Urban planning should favour compact cities and make using public transport easy. Providing a clear framework for shared mobility solutions will ensure that these services complement public transport and do not compete with it. If governments take action on these fronts now, we can shift transport emissions onto a solid downward path.

We talked about the COP25 conference in Chile in December. What is the host country doing to encourage greener transport?

PC: Chile has the largest fleet of electric buses in Latin America. There are more than 200 electric buses on the roads of the capital Santiago today.

All 6 000 buses of the capital’s network will be successively replaced. President Sebastian Pinera has in fact pledged to electrify the public transport system across the country by 2040 – and, importantly, also set the goal of sourcing all of Chile’s electricity from renewable energy by that date.

Thank you so much for your time, Pierpaolo.

Pierpaolo Cazzola is Advisor for Energy, Technology and Environmental Sustainability at the International Transport Forum (ITF). His interests include creating synergies between the transport and energy expert communities, life cycle emissions of urban mobility options, and the global fuel economy. Currently he is investigating how India is mitigating transport CO2 emissions as part of the ITF project “Decarbonising Transport in Emerging Economies”. Pierpaolo is the author of numerous reports, including most recently the 2019 Global EV Outlook. He has worked at the International Energy Agency (IEA), the United Nations, the European Commission and the OECD.