Walkability and Climate Change
How do we get to a world where temperatures do not rise 2°C past pre-industrial levels?
Walking is one of the first notable things we learn to do as humans. Somewhere around the one-year mark, infants go through the celebrated process of trial and error that comes with learning to stand up by oneself, stumbling and bumbling their way into the anthropogenic sophistication of bipedalism. As early as 6 million years ago, our primitive ancestors did the same, transitioning from the ape-like movements of their forebears to the upright statures practiced by the 7 billion-odd people across the globe today.
Walking, however, is not nearly as popular as it used to be.
Beginning in the early 20th century, private automobiles began populating the streets of industrialized countries, with production exploding after the end of World War Two. Across the United States in particular, cities began taking shape around the car. Veterans lifted their boots from the sands of North Africa, the cobblestones of Europe, and the beaches of the Pacific Theatre, hopped on great ships back to the U.S., and placed them for a permanent tenure on the square-cut lawns of the suburbs. White GIs did so partly out of disdain for inner cities that were increasingly black, partly due to the increased income that came with a university degree (paid for by the government through the GI Bill), and partly due to perceptions that the suburbs were havens for people who wanted to live a more individualistic lifestyle. But, above all else, it was the advent of the private automobile that let the suburbs thrive.
Single-family homes are the lowest density housing option a developer can choose when deciding what to build on a piece of land. Each unit requires a massive amount of space to fit not only the built structure of the house itself, but also the open yard around it and the road in front of it. To highlight how inefficient the suburbs are at utilizing land for housing, look at the two types of urban development in the images below.
This image displays a typical American suburb. Each house has a front yard with a driveway, a back yard, and some side yard space, while a car-oriented street wraps around the whole site. Its density? Roughly 4 dwelling units per acre.
This image, on the other hand, shows a 6 floor apartment building with some retail spaces on the bottom floor. Its density? 162 units per acre.
That means that the normal American suburb takes up over 40 times the amount of land area as a mid-height apartment building. As suburban sprawl has come to dominate our built landscapes, that also means that the land occupied by human settlements is tens of times larger than it needs to be. Besides the obvious consequence of destroying natural habitat, this absurd expansion of paved roads, 3 bedroom houses, and grass plots is also responsible for one of the greatest contributors to greenhouse gas emissions on the planet: gasoline-powered automobiles.
Since the suburbs are so large and sparsely populated, living in them practically requires the possession of a private car. Few suburbanites can imagine themselves walking to the grocery store, post office, restaurants, or other places of frequent visit. They’re simply too far away. Mobility is tied to the automobile.
The following map from the San Diego Association of Governments shows the effect of sprawl on how often people drive.
In downtown San Diego, where the built landscape is far denser than surrounding areas, the average VMT (vehicle miles traveled per day) for each resident is far lower than that of communities dominated by single family housing. In urban centers such as this, it is much easier to walk, bike, or take public transit to get from place to place. Food, retail, housing, and recreation are often all within a few blocks of each other.
This means people rely less on their cars, SUVs, and pickup trucks - which together account for almost 70% of all greenhouse gas emissions in California's transportation sector, and 28% of California's greenhouse gas emissions overall - to get around. Decreased VMTs are one reason why dense urban cities are far more sustainable than their sprawling suburban counterparts.
Even in cities that are densely populated however, it can still be difficult to walk from one place to another. Despite having tall residential towers, skyscraping office buildings, and prolific amounts of human activity, most American cities still aren’t structured in a way that gives preference to people over cars. Wide multilane streets, narrow sidewalks, space-hogging parking lots, and sparse amounts of vegetation are all features of poor urban design tailored to explicitly accommodate automobilists. These features simultaneously restrict the amount of space available to pedestrians, as famously illustrated in this cartoon by Karl Jilg.
Redesigning our cities to prioritize walkability comes with a long list of benefits, including, of course, a potential to mitigate climate change by reducing fossil fuel consumption. Still, such an endeavor is no small task to accomplish, and several concerns are common amongst people reluctant to break away from their car-dependent lifestyles. Here are some of the most popular, with simplified responses:
1. “Restructuring the public space within our cities seems like such a massive undertaking. I don’t believe the government should be interfering this much in an effort to influence how I can or cannot get around.”
Response: There is no doubt that this sort of restructuring would require a massive undertaking. However, it would pale in comparison to the size, scope, and cost of the incredible infrastructure projects subsidized by the federal government during the 1950s. The construction of freeways and roads during that time — many of which were created by literally leveling entire corridors of buildings in cities — was extremely costly, and this wave of infrastructure had a much more specific intention of elevating one form of mobility (private automobiles) over every other option. Currently, cars take up a disproportionate amount of space in our communities. Giving some space to other forms of transportation is simply leveling the playing field.
2. “Traveling by car is quicker than traveling by foot, on a bicycle, or using public transportation.”
Response: If you live in the suburbs or in a rural area where everything is so far apart from one another, this is likely true. However, in urban centers where traffic congestion is prolific (thanks to the incredible amount of space private automobiles take up in comparison to how many people they actually carry), several studies have shown that bicycling can get you from point A to point B faster. In any case, if you live in a dense urban center, most of the places you need to travel to for weekly needs are within walking distance.
3. “Walking and taking public transit can be dangerous.”
The potential danger from walking or taking public transit ranges widely from place to place and varies across the different times of day. However, the danger in and of itself does not come from the actual form of transportation; in the case of walking, for instance, it is a product of the neighborhood you walk through. Furthermore, in 2019 alone over 36,000 Americans died in car accidents, making it a leading cause of death amongst young age groups.
While cars will still be needed by many people in rural areas to get from place to place, it is time to stop prioritizing their mobility over that of pedestrians’ in our urban centers. Increasing walkability is a smart objective to reach for that will not only help us in the fight against climate change, but one that will also make our communities more livable, efficient, and prosperous.
Lastly, some food for thought. Here are four photos illustrating how much road space is needed to accommodate 200 people in cars, buses, or light rail. Which seems like the best option to you?