• View
• Edit
• History
• Print

Towards Low Emission Cities

 

The future is already here, it’s just not evenly distributed.

— William Gibson

The Climate Change Commission’s advice to the Government includes the following recommendation.

Change the way cities and towns are planned and designed.

The Government needs to do what it can to improve existing communities to support emissions reductions, and make sure that new developments are planned in a way that is compatible with a low emissions future.

Many cities are further along the path to low emissions than those in New Zealand. What do we know about cities with the lowest per capita carbon footprints? The big idea is that a low-carbon city is a by-product of creating a more liveable, more just city, not an end in itself. It turns out that low-carbon cities share a number of features.

1. Most people live in amenity-dense neighbourhoods, close to all important urban services. Core services include: a grocery store, pharmacy, café and transit stop within 1 km; child-care, a primary school, park and library within 1.5 km; secondary school and health care within 3 km; and places of work or tertiary education within 10 km.
2. Low-carbon cities put pedestrians first. For example, at intersections, cars must give way to pedestrians; at traffic lights, pedestrians automatically get a walk light; low- and no-traffic streets prevent rat-running through residential neighbourhoods; traffic calming makes walking easier, safer and more attractive; many services are within a 1.5 km walk from home.
3. They have great public transport, with a frequent and reliably on-time bus network and a rapid transit network to bring remote services closer. Frequent means service at least every 15 minutes, at least 12 hours a day, 7 days a week; reliable means cars give way to buses and bus lanes let buses avoid getting stuck in traffic; rapid transit operates on dedicated corridors with priority at intersections.
4. They have comprehensive bike networks, segregated from other traffic. Travel by bike is safe for people from 8 to 80. Local streets are low speed, low volume. On arterial streets, kerbs keep bike lanes physically separated from motor traffic. People on bikes can complete most journeys without mixing with traffic. Cycle helmets are recommended but not required.
5. People have cars, but they use them less, because the alternatives are more attractive. At least half of all journeys are on foot, by bike or on public transport. Amenity-dense neighbourhoods mean most trips are short and longer trips are infrequent, so vehicle km travelled per capita is much lower than in high-carbon cities.

In the lowest-carbon cities, at least three quarters of people live in amenity-dense neighbourhoods and past investments in transport infrastructure mean they live in a 15 minute city. That is, in 15 minutes from home, people can travel up to 1.5 km on foot or by scooter, at least 3 km by bike or bus, and up to 10 km on rapid transit. This approach to urban design is sometimes called density done well. These cities can afford a slower take-up of electric vehicles, as they are starting from a low emissions base.

Low-carbon cities are multi-modal — people can choose the modes that best fit their journeys. As a result, they are also efficient — space-efficient, time-efficient, and energy-efficient. In contrast, high-carbon cities are less amenity-dense, more uni-modal and more car-dependent.

The lesson for New Zealand is that it is better to avoid carbon emissions in the first place than to invest in technologies, such as electric vehicles, to decarbonise emission-creating activities. The challenge for us is that retrofitting 15-minute transport infrastructure is expensive and disruptive. Auckland is discovering that light metro (a 15 minute technology) is at least twice as expensive as the slower on-street light rail. Frequent bus services are expensive to operate through low-density neighbourhoods.

The Climate Change Commission is silent on amenity density. Under transport, it recommends three areas for the Government to focus on:

• reduce the reliance on cars (or light vehicles) and support people to walk, cycle and use public transport;
• rapidly adopt electric vehicles (EVs); and
• begin work now to decarbonise heavy transport and freight.

This leads to and leaves us with some big questions:

What is the right mix of emission reduction (convert the vehicle fleet to electric) and emission avoidance (mode-shift to more walking, cycling and public transport)?

Do we invest in offering the sweetest carrots and aim to create amenity-dense 15 minute cities; or

Do we invest in less sweet carrots (e.g., aim for 20 minute cities) and use more sticks like congestion charges and carbon fees?

What can individuals do? My advice is that when you next move house, consider moving to a more amenity-dense neighbourhood.

As we reshape our cities, we need to keep in mind what Jane Jacobs wrote. Whenever and wherever societies have flourished and prospered rather than stagnated and decayed, creative and workable cities have been at the core of the phenomenon. Decaying cities, declining economies, and mounting social troubles travel together.