The north shore of West Seattle, zip code 98116. Photo taken in 2010.
We've heard for decades that increasing population density is good for the environment. The idea is that it discourages suburban sprawl, which means less driving, less energy consumption, and lower CO2 emissions.
But how do we know if this is true? Where is the data?
The CoolClimate Network has taken on that challenge. Among other things, they took on the ambitious project of measuring the CO2 output of every zip code in the United States. In 2013, they published their results, along with an interactive map you can use to find your zip code and measurement. In the Tools menu, you can select the household calculator to see what your personal score is and compare it with your neighborhood overall.
These measurements take into account the categories of transportation, housing, food, goods and services used per household. Annual household emissions range from 16 to 80 tons/year.
For those of us who live in the 98116 zip code, how do we stack up? Our score is 43.5. Not great, but not terrible, either. Here are ratings for other West Seattle zip codes:
98126 43.1
98136 46.6
98146 46.8
98106 43.2
Here's a look at Downtown Seattle, which has greater population density than the rest of the city:
98104 21.6
98134 28.6
How about the suburbs?
98006 61.4 Bellevue
98011 51.3 Bothell
98032 40 Kent
98040 62.7 Mercer Island
98056 47 Renton
98070 52.3 Vashon Island
98110 53.6 Bainbridge Island
98168 44.3 Burien
98177 56.1 Shoreline
98271 54.2 Everett
The biggest producer of CO2 in the region, by far, is Medina, with a score of 77.3 out of 80. Medina is home to Bill Gates and Jeff Bezos, billionaires who talk a lot about climate change, but who could stand to make some better choices on a personal level.
This quick survey of local data supports the claim that density reduces CO2 output. It is also an example of a pattern that is seen in cities across the country. Inner city, densely populated areas have lower emissions. They are surrounded by higher emission neighborhoods and suburbs.
This is something to think about as we work toward improving life in our communities. It is worth calculating our personal CO2 generation and looking for ways to reduce it. Politicians and philanthropists talk about solving the climate crisis, but in the end, it will be up to the rest of us to make it happen.