NYT Report Confirms That Density Reduces Household Emissions

Photo: Raymond Boyd / Contributor (Getty Images)

If there was still any doubt that dense cities are better for the environment than urban sprawl, the latest New York Times report on the subject should put an end to that once and for all. It’s a fantastic read that uses research from the University of California, Berkeley to show in granular detail how household greenhouse gas emissions vary across the country. And the news is not good for wealthy suburbs.

Instead of focusing on greenhouse gas emissions at the source, such as power plants, farms, and vehicles, UC Berkeley used a consumption-based model to estimate household emissions. “When individuals or households want to know what influence they have over emissions, a consumption-based carbon footprint is the most relevant indicator,” said UC Berkeley’s Dr. Chris Jones. “And it can help us see what sorts of larger systemic changes are necessary.”

The initial goal of the research project, which started more than 10 years ago, was “to help people understand how their choices contribute to a global problem.” But according to Dr. Jones, he soon realized the data could be more helpful as a tool for local governments hoping to fight climate change on a larger scale than any single person could on their own.

UC Berkeley also gathered data on a lot more than just driving habits and housing:

The researchers used a model, a simplified mathematical representation of the real world, to estimate the average household’s emissions in each neighborhood based on electricity use, car ownership, income levels, consumption patterns and more. Driving and housing are frequently the largest contributors to a household’s carbon footprint, although what people eat, what they buy and how often they fly are also important factors.

Screenshot: New York Times

The study found that dense, walkable, mixed-use areas with good access to public transportation had the lowest household emissions, with suburbs and exurbs having two or three times higher household emissions on average. But where people live isn’t the only factor. Household income was another big one, since rich people tend to have larger houses, fly more frequently, and buy more things than their less wealthy neighbors.

As the article points out, the results show an average for each census tract, so there’s going to be some variation from household to household in any given area. If you live in a suburb and work locally while your neighbor commutes into the city every day, your individual household emissions totals are going to be different. But at the same time, a lot of other factors are outside of personal control.

“Consumption is not the individual act we all think it is,” Siobhan Foley, head of sustainable consumption at C40, a group of 97 cities working to fight climate change, told the Times. “We treat it like a personal choice, but it’s shaped by all these other factors.”

Unsurprisingly, two of the biggest factors that are largely outside of individual control are housing and zoning laws. The dense urban areas that have the best household emission averages simply aren’t allowed in most of the country, thanks to zoning laws. And where density actually is legal, local governments haven’t done anywhere near a good enough job of approving enough new construction to meet demand.

A lot of times, that’s by design. As the article points out, local governments in wealthy suburbs zone for large single-family homes and outlaw apartment buildings, effectively blocking any changes that could improve their area’s climate impact. It’s the same story in cities, where apartments and mixed-use developments are only legal to build in small areas. And even in areas where density is legal, plenty of lawmakers block new construction to keep housing prices high and their land-owning constituents happy.

As Jenny Schuetz, a housing researcher at the Brookings Institution, put it:

We need to be building smaller homes in denser places, closer together and closer to jobs, to public transportation. But the locations where we should be adding a ton more housing have made it really hard to build. Manhattan and Inner Brooklyn should have probably doubled their housing stock in the last 20 years. They didn’t. And so a lot of houses got built out in Long Island, in the Hudson Valley, out in New Jersey instead.”

Yes, there are other things local and state governments can do to reduce household emissions, but according to Dr. Jones, the single biggest factor really is building more housing. Specifically, he points to infill housing, not giant skyscrapers. Building more apartments and townhouses in areas that already have room for them reduces car dependency, reduces household emissions, and also gives people choices that they didn’t have before.

We’re not talking about small reductions in greenhouse gasses, either. To solve the national housing shortage, an estimated 20 million housing units will need to be built over the next decade. The think tank RMI analyzed Dr. Jones’s research and found that by clustering those new homes in denser, more environmentally friendly areas, by 2030 the U.S. could lower CO2 emissions by 200 million tons per year. By the Times’s math, that works out to be about the same as removing 43 million cars from the road. So yeah, climate-friendly development could have a significant impact on greenhouse gas emissions.

And while it would be nice to have more affordable options in areas where you don’t need a car to get around, even areas where you still need a car benefit from smarter planning and development. Locating stores and restaurants closer to suburban neighborhoods means that even though residents still drive to get there, they make shorter trips. That’s not just good for the planet, either. It’s also better for overall quality of life and not having to spend as much money buying gas every month.

Some will inevitably see this research as an attack on cars, freedom, and the American way of life, but we continue to maintain that density is better for car enthusiasts, too. Among other benefits, it gets more bad drivers off the road, reduces congestion, frees a lot of people from needing a practical daily driver, and gives enthusiasts more resources to devote to the hobby.

After all, how are you supposed to find time to modify your Miata if you spend hours commuting during the week and then spend all weekend carting your kids around? Wouldn’t it be better if you had a shorter commute, and your kid could ride their bike to the birthday party they were invited to? And wouldn’t it be more fun to drive that Miata on roads that aren’t congested with everyone else’s cars?