Transport is Australia's third-largest, and fastest-growing, source of emissions. If we're to have any chance of keeping climate change to 1.5°C, we have to urgently clean up our transport system - but how?
Some advocates seem to think it's as simple as transitioning to electric cars and trucks as quickly as possible, but unfortunately the reality is much more complex than that, and getting that complexity across to politicians, public servants and the general public can be quite challenging. We need a few simple guidelines for how to decarbonise quickly and effectively, so that everyone can get behind the same priorities - this is my attempt to provide those simple guidelines.
Today we'll look at what the rules of thumb are, and why they're the priorities, and in the next three posts I'll go into more detail about how we can implement these priorities.
People will be familiar with the mantra "Reduce, Reuse, Recycle". Recycling something is much better for the environment than letting it go as waste to landfill, so if something has reached the end of its useful life, we should definitely recycle it. But the higher priorities are to Reduce our consumption (try not to have unnecessary packaging or products created in the first place) or to Reuse (find a new use for something and thereby extend its useful life).
"Reduce, Replace, Repower" is the equivalent mantra for transport (1). Just as recycling is way better than landfill, electric cars are way better than Internal Combustion Engine (ICE) cars, and presumably electric or hydrogen planes will be better than kerosene planes - but repowering cars and planes shouldn't be our highest priority. Our highest priority is to reduce the amount we travel; then to replace dirty trips with clean ones; then to repower dirty vehicles.
Keep in mind, though, this isn't a chronological order. It can help us to understand where to prioritise our campaigning energy, or our government budgets - and when a policy has tradeoffs, to make sure we don't focus on the wrong thing. But we should definitely be doing them all at the same time.
Reduce
 |
| Mixed-use building with ground-floor retail and three residential storeys (via Ceescamel) |
The highest priority is to reduce unnecessary travel. In some instances this might mean avoiding trips entirely, for example using Zoom to avoid overseas trips for business and conferences. But mainly it's about reducing the distances that people need to travel for everyday purposes. Through better planning of our cities, we can make it so that most daily activities - shopping, GPs, schools, parks and sporting facilities, and in some cases jobs - are within a 10 minute walk or bike ride of home.
Part of this involves putting more of those trip destinations closer to trip origins. Research suggests that doubling the residential density of an area can reduce household travel demand by 5-12%, and combining this with access to jobs and services can reduce it by 25%. But it's not all about density, it's also about the mixture of land uses - if a suburb has only houses, you have to leave the suburb to buy food (or anything else), increasing travel distance. Whereas if you have corner stores and small shopping strips dotted throughout a low-density suburb (as was common in small towns and suburbia not so long ago) that helps people to stay local, even if the density doesn't increase at all.
The other part of this is the urban form itself - the layout of modern streets, riddled with cul-de-sacs and squiggly crescents, often means the distance we have to travel is way further than the crow flies (and can often make suburbs difficult to serve by bus). Simpler grid-like street layouts, or even just linking up cul-de-sacs with footpaths, can significantly shorten the distance people need to travel from their house to the shops, or to the bus stop on the nearby main road.
 |
| Squiggly streets make even short distances unwalkable (via Streetsblog USA) |
Driving shorter distances has obvious carbon benefits. But in many cases these changes will cut long car trips down to a walkable or bikeable distance, potentially getting people out of the car entirely - which has even bigger carbon benefits. These kinds of urban forms also help to reduce suburban sprawl, which eats up green space on the edge of cities, and increases the pressure to clear bushland to turn into farmland further afield - which has obvious implications for climate change and biodiversity.
Retrofitting existing suburbs to meet these ideals can be a slow and difficult process, but new suburbs are being built every single day with the exact same problems - fixing the planning rules to get this stuff right ASAP will deliver big wins over the next few decades as those new suburbs are built, so it has to be our highest priority.
Replace
 |
| Prioritising transport for emissions, safety, space & activity levels (via Bicycle Network) |
The second priority is to replace travel that uses unsustainable modes like planes and cars, with more sustainable modes like walking, cycling, and public transport. The improvements to urban form that help us reduce travel can help with this, but don't solve the problem on their own - density is not destiny. We have to actually improve the walking and cycling infrastructure, and provide the quality bus, tram and train services, to facilitate people changing their modes of travel.
Households in growth areas need multiple cars just to get around (via ABC News)
This doesn't require people to go completely car-free; it's about reducing car trips, not cars themselves, so a person might make 80% of their everyday trips by other modes but keep the car for the 20% of trips that are awkward without one. Car ownership rates should drop, though, because lots of two-car households will be able to drop to one-car households, and three-plus car households should become a thing of the past.
Why is replacing car trips with other modes so important? Focusing solely on switching ICE cars to EVs is the incredibly slow way to decarbonise. Norway is often lauded as the golden child when it comes to EV policy, and their policies have been incredibly successful in getting electric and hybrid vehicles to overtake ICE car sales - petrol and diesel vehicles combined were only 8% of sales in 2021! But even so, the vast majority of kilometres driven on Norwegian roads are still done in petrol and diesel vehicles, simply because the existing ICE fleet is so huge and lasts so long.
 |
| Most new car sales are clean, but most kms driven are still dirty (via @robbie_andrew) |
Even if we adopted a bunch of Norway-style policies to promote EVs tomorrow, we'd be many years away from reaching 100% of new sales, and close to two decades away from transitioning the whole fleet. That is simply too slow.
What if we went further than Norway, and adopted even more aggressive measures to promote and subsidise EVs, to make that transition happen faster?
The problem here is that the act of building a car is itself an environmentally damaging process, and "moar consumption" doesn't help. Extracting the minerals from the ground, creating raw materials like steel and aluminium, shipping materials to factories, building the car, and shipping it to Australia, gives a car a lot of embodied emissions - whether it's an ICEV or an EV. (Not to mention the destruction to local plant life and water tables, and human rights issues, that the mining often causes).
This is improving over time, eg by using renewable energy in the factories. But decarbonising the mining process and international shipping are nowhere near as quick or easy; and increasing demand over the next decade (especially for lithium) is going to incentivise less scrupulous operators to cut corners. Pushing to make the EV transition faster by, say, scrapping ICE vehicles that are still in good working order, would only compound those pressures.
 |
| Even diesel buses are incredibly green when lots of people use them |
By contrast, replacing car trips with walking, cycling or public transport trips can instantly slash emissions - an ICE car with the average peak-time occupancy of 1.1 people emits 200g of CO2-equivalent per passenger-kilometre; an EV charged off the 2020 Victorian grid emits 130g per passenger-km; and a diesel bus with just 10 passengers emits 86g per passenger-km. And of course, if we can encourage lots of people onto buses by improving services, a diesel bus with 40 passengers emits just 22g per passenger-km. Obviously the greener the vehicle the better, so electric buses make these cuts even deeper - but the number of people you can divide it by is absolutely crucial, and PT is just inherently way more efficient at moving people than cars are.
And of course, the humble bicycle is basically zero carbon, as is walking - so these offer even bigger savings where they're practical.
Even setting aside all the non-carbon externalities of cars that make our cities worse, we cannot possibly replace ICE cars with EVs quickly enough. Replacing car trips with walking, cycling and public transport must be a key part of the plan as well.
 |
| Trains can have 90% fewer emissions than planes (data from Eurostar) |
When it comes to long-distance travel, there is no currently-viable technology for zero-emissions aviation. I'm sure we'll eventually solve this, but we can't afford to do nothing while we wait to repower. Reducing flights should be our first priority, but replacing flights also provides opportunities for very low-emissions travel. On routes like London-Paris, ditching the plane and taking the electric Eurostar train means 90% fewer emissions. The gap is smaller for the diesel trains (and coaches) we have in Australia - based on UK figures, a diesel train will emit about twice as much as an electric one - but this still represents huge savings over flying.
Obviously this isn't practical everywhere; over longer distances, and particularly over water, we have little choice but to fly. And of course, some improvements to Australia's interstate rail services (like higher frequencies and reliability, and modest speed improvements) could happen relatively quickly, while others (like full-blown High Speed Rail) would take a lot longer. But by replacing those shorter trips as much as we can - and getting stuck into improving those rail options for people - we can slash emissions and buy ourselves the time to solve the long-distance problem.
Repower
 |
| Electric vehicle and charger (via Walter Baxter) |
The last priority is to repower our transport.
A substantial number of cars will still be on the roads even if we succeed in the first two steps, so they need to be powered from zero-emission sources - whether they're electric batteries, hydrogen fuel cells, or something else. Because there's so many cars and they're so long-lived, this will take a long time - so we should set up the right policies for this transition ASAP. Every day we keep putting new ICE vehicles on the road locks in 20-odd years of emissions, so the sooner we stop doing that, the better.
The same goes for planes - we can reduce flying to buy ourselves time, but planes will still exist so we need to find a way to decarbonise them. Similarly, we might be able to reduce international shipping with more local manufacturing, eating more locally-grown food, etc - but we'll still need a lot of international shipping so we need to find ways to clean it up.
And of course, when we succeed in shifting car and plane trips to buses, trams and trains, many of these public transport vehicles will be directly or indirectly fossil-powered. In Victoria, almost all our buses are diesel-powered, as are our regional trains, so we need to transition them to electricity (or green hydrogen) - and where PT vehicles are electric, we need to ensure they're powered by renewables (thankfully already the case with Melbourne's trams).
 |
| Melbourne's trams are already solar powered (via Liamdavies) |
Conclusion
As I said at the start, this isn't a chronological order, it's about policy priorities - when we're thinking about which policies to implement, this should be the prism through which we view them.
So as I said, we need to get our EV policies in order ASAP. But should those EV policies include, for example, giving EVs priority lanes as Norway did?
Our roadspace is finite and hotly contested, so the priority should be to add bus lanes, or separated cycle lanes, or both. If there's room to do all of these and give EVs a quicker journey, that's great. Something like an Ultra Low Emissions Zone, where EVs and Hybrids travel free but full ICEVs must pay, might deter ICEVs and free up space for EVs and Hybrids - maybe a way of having our cake and eating it too. But where there is finite roadspace and we have to choose between prioritising Replacing or Repowering, it's clear which way we should go.
Or, for example, if the Department of Transport has only got a limited amount of funds out of the Treasury for bus upgrades, should they spend it on electrifying the bus fleet or on reforming and improving bus routes and timetables? Obviously the ideal scenario is to do both - improve routes, run buses more often, while also ramping up the transition to electric buses - and advocates and citizens should be pushing government to do both. But if they've only got enough funds on hand to do one or the other, the service improvements are probably the priority, since this will do more to encourage people to Replace car trips.
Reduce, Replace, Repower is the fastest way to decarbonise - realistically, the only way that will be quick enough to give us a chance of keeping to 1.5°C. It also has many co-benefits - it will make for a healthier, safer, less congested, more prosperous and more equitable world - but I'm not focusing on that here, because even if you don't care about any of those things, even if you only care about decarbonising as quickly as possible, it's still the best framework because it's the fastest.
Today I've dealt with the what and the why of Reduce, Replace, Repower. The next three posts will go into more detail about how we can actually implement these three priorities - up next is Reduce.
1. These terms are mine, but the concept isn't. The terms used by the Germans who came up with this framework were "Avoid/Reduce, Shift/Maintain, Improve", commonly abbreviated to ASI. But "Avoid" doesn't really seem the best to foreground when it's mostly about reducing travel rather than avoiding it entirely. Also, "Maintain mode share" is not sufficiently ambitious for public and active transport, we have to increase their mode share. "Improve" basically works, but I think "Repower" more accurately captures what we're trying to do. Plus, it's catchier with 3 Rs - in the original German it was 3 Vs
No comments:
Post a Comment