Decarbonising Transport

Professor Iain Docherty, Institute for Advanced Studies, University of Stirling

Hello, everybody, I’m Iain Docherty, Dean of the Institute for Advanced Studies at the University of Stirling, and this is my bite-size lecture for COP26 on Decarbonising Transport.  

Transport and climate emissions 

I’m going to spend the next 10 minutes or so speaking about transport and emissions from the sector that contribute towards climate change.  

First of all, I’ll speak about the state of play in terms of the current emissions profile of the transport sector in Scotland. Then I’ll make some comments about what a realistic pathway to achieving net zero in the climate change emissions reduction targets that we have set out in legislation might be. Then at the end, I’ll review some of the critical challenges that we all as travellers and users of the transport system will have to think about as we change our own behaviour to help meet these targets. 

To begin, what is the state of play as it is now in terms of the greenhouse gas and climate emissions from the transport sector? In rough terms, the transport sector accounts for 40% of all the greenhouse gas emissions in Scotland. That figure varies a little bit depending on the precise definitions that are used, but it’s roughly 40%. 

In recent years, rather than improving the emissions profile of the transport sector has actually been getting worse. We’ve long known that transport is one of the most difficult areas of the economy to decarbonise. But in recent years, that picture has become even more negative, with some really quite steep increases in emissions. You can see from the graph that after the global financial crash in 2008- 2009, emissions began to fall quite steeply, perhaps as you might expect, but then in 2013 they bounced back quite significantly. 

Of that 40% of emissions attributable to the transport sector overall, 40% of transport emissions are due to the private car, as you can see from the graph here. That, of course, is only one element of road transport, albeit a single biggest one when you add in light goods vehicles and heavy goods vehicles. You’ll see that the proportion of transport emissions that we have from road transport is significantly more than half. 

You can probably also see from the diagram that aviation, despite being a very small proportion of the overall number of trips that we take, is responsible for a very high and increasing proportion of emissions, roughly 15%. If we think about how that emissions profile between transport modes has changed since 1990 which, as you may know, is the baseline year for emissions which many of our climate change targets are set against and when our current data in this form really dates from, you can see from this graph that aviation emissions have increased by almost 60%. But perhaps most remarkably of all, the emissions attributable to light goods traffic in Scotland have almost doubled with an increase of around 96%.  

In the very latest figures that we have access to, which are for 2018 so obviously before the COVID 19 pandemic, which has brought unprecedented disruptions in the transport system in Scotland, the UK and worldwide, things had started to improve. But, even in 2018, the emissions profile of the transport sector looked pretty much the same as it did in the 1990 baseline figures. And so, although emissions from transport in Scotland have declined for the first time since 2013, we only got back to the very beginning of the data series against which all of our targets are calculated, if you compare that to the decarbonisation achieved in some other sectors, most notably the electricity industry in Scotland, you can see just how slow progress in decarbonising transport has become. 

In short, transport and travel represent roughly 40% of our carbon emissions. Of that 40%, 40% is private cars. Pre-COVID, things really hadn’t improved in 30 years, despite the importance of acting quickly to ensure that not only we meet our targets in terms of 2045 for achieving net zero, but in terms of the carbon budget that we might be able to afford if we are to limit global temperature rise, and you’ll have heard lots of conversations and analysis about that during COP so far. In many respects, some of our key sectors within transport have been deteriorating, rather than improving; so, van deliveries have become a bigger part of the emissions profile; car engines have become more efficient, but we, as consumers have reacted to that by buying larger ones with no net reduction in the emissions from the car fleet. And of course, there’s been more aviation.  

Pathway to net zero 

Given that rather negative background, what might a pathway to net zero look like? Many of you no doubt who read the media, the newspapers, TV, radio about transport decarbonisation issues will be aware that rolling out electric vehicles and perhaps hydrogen vehicles seem to be the most important thing that we can do. Now on one level, of course, that makes sense. And as you can see from the kind of advertising that the car companies do, what they’re desperate to convince us all is that we’ll be able to travel in much the same way as we did today, but just using vehicles that are powered by different cleaner fuels. The problem here, of course, is that that’s not strictly true. 

We know from climate modelling, that technological solutions are not enough. There are various reasons for that, but one of them is the energy and the embedded carbon in the vehicles themselves. So even if we were to decarbonise all of the vehicle fleet tomorrow, which is clearly impossible, even if we were to do that in order to meet our net zero targets, we probably have to do with something like 20 or 25% fewer cars and vans in the fleet overall. 

So, we are going to have to change how we travel around. And this is a snapshot of the ways in which we currently travel, and it shows you the dominance of the car, and that really big slice of emissions in terms of our daily lives and what the transport system looks like in 2021. About two thirds of all journeys in Scotland are made by car. Perhaps surprisingly, you might think walking is the next highest with 20 percent. But public transport and particularly cycling are really quite small parts of the overall picture. Clearly, if we’re going to achieve decarbonisation, we’re not just going to have to change the technology that powers our road vehicles, but we’ll have to change how we travel to become less reliant on them. 

In terms of aviation, which has gone through a really strong period of growth in the run up to the COVID pandemic, and for which the calls from the aviation sector to get back to normal, as it puts it, in terms of the level of aviation and future growth once we move out of the pandemic, there’s a clear tension there between the desires of the industry to continue to grow and its environmental implications. Though we still don’t have any realistic technical means of decarbonising and aviation beyond very short flights, but perhaps to the Scottish Highlands, for example and that’s not where the demand for aviation is growing.  

We’ve lived through 20 or 30 years where flying has become something that more and more people do. And we’ve also lived through a period where there have been really quite odd incentives to get people to fly even more than they’ve done in the past. The classic example of that is frequent flyer miles which is something that is absolutely the opposite from what we need to encourage and what we need to move to really quickly, if we have to change behaviour. 

What is fair? 

In terms of some political challenges, perhaps the most important one of all is to make sure that collectively as a society, we are able to undertake a transition to a less carbon intensive transport system, but to do so in a way that is fair.  

Now again, this is a word that gets misused really, quite importantly, I think. There is a very well-known campaign in the UK called Fair Fuel and by some estimates, Fair Fuel has been responsible for the reduction in the level of tax levied on petrol and diesel of something in the region of one hundred and fifty billion pounds since the previous fuel tax escalator. That was the automatic increase in the levels of tax applied to petrol and diesel was abandoned about 15 years ago. This, of course, is argued on the basis of fairness.  

But things are not that simple. On the one hand, we failed really to do some things we’ve known about for a long time, like planning better and building our new houses in the right places. We have locked in some people into car dependent lifestyles that perhaps they didn’t want to have. We have a big problem in Scotland that’s called forced car ownership, where people who would rather spend the limited resources of their household income on other things are obliged, in fact, to do so on travelling by car because they have no alternative. 

Then at the other end of the income scale, people with more disposable income are spending more and more of it on consumer goods and demanding an even more intense transport system to get those goods to them. I imagine that nearly everybody who’s watching this lecture will have seen on Amazon or another online delivery retail platform, that the timing for delivery has shrunk and shrunk and shrunk. That explains the massive increase in emissions from light traffic that we have because our own consumption behaviours are becoming even more dependent on fossil fuels transport to the extent that although the image in the website might tell you that somebody is going to come by bicycle to deliver your package, in fact, it’s more and more of those vans that are on the road. 

Slow down 

So, if we are to do anything to meet our carbon targets over the now very limited time that we have left to get not just the 2045 target for Scotland, but perhaps to the even more difficult 2030 target to reduce our carbon emissions by 75 percent, we are all going to have to slow down.  

We’re not going to stop flying. But those of us who are able to do so will have to fly less. 

Those of us who are able to afford a car will have to use it less. We’ll have to walk more or have to cycle more, and we’ll have to use public transport more. 

And when we shop online, we might think the environmental impact of what we’re doing is much less than I’d be driven into the city centre to go to the shops.  

In fact, as the logistics system becomes more complex and reacts to our increasing demands, things are not so simple. So just pressing the buy now button on Amazon is also something that we’ll have to do less often in the future if we’re going to meet our decarbonisation targets. 

Thank you for listening. The final thing I’d say though is if this sounds like quite a negative picture, in many ways it is difficult. There’s no denying that the transport sector is going to be a hard nut to crack. Remember that there are lots of people who are already travelling less.  And when people do that, they generally report that they feel happier on their levels of well-being have improved. So perhaps the future is more positive than we might think, and if we are able to stop rushing around quite as much as we’ve done in the last few years, maybe we’ll find that not just the transport system begins to decarbonise at the pace we need, but also, we might feel better for it too. 

Thank you very much for listening. Travel less and travel safely. 

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