When measuring greenhouse gas emissions, there are two main ways to look at responsibility: person-by-person or geographically. Individuals have a collective carbon footprint that we each must work to reduce. And countries, states, and cities each have a share of global greenhouse gas emissions that they’re responsible for. Right now, China is the leading culprit, with the United States not far behind.
If a community wants to look at its true carbon footprint, it must consider both parts: the emissions produced within its geographic bounds as well as those attached to its citizens’ consumption. There’s no standard approach to that calculation, but a new study [PDF] takes a stab at quantifying the footprint of one community, Washington State’s King County.
For a wealthy community like King County, where local industries aren’t particularly energy-intensive, counting emissions connected to consumption makes a dramatic difference. The study, conducted by the Stockholm Environment Institute, found that emissions produced by citizens’ consumption were more than double the emissions produced within the county’s borders.
In a perfect world, international negotiators would come to strong multinational agreements about tamping down carbon emissions, and that disparity wouldn’t matter: Governments would be working on limiting emissions across the board. But in the world as it exists today, a community that wants to decrease its carbon emissions needs to consider its consumption too.
King County, which includes Seattle, provides an excellent example of why consumption emissions matter. The area has a lot going for it, carbon-wise: It enjoys low-carbon electricity from hydroelectric sources; its citizens drive fewer miles on average than Americans as a group; its buildings use less energy than the U.S. average. But overall, the county’s per-capita emissions come in slightly above the national average. For all the good the county’s clean electricity, sustainable transportation, and energy-efficient buildings do, consumption makes up the difference.
Using this information, local governments, nonprofits, and activists who want to encourage reduced consumption can make strategic decisions about which green lifestyle choices to promote. Cars still contribute the most to total emissions, and cooling and heating buildings account for the second-largest piece. But the overall message does change somewhat: Emissions associated with categories like food, goods, and services aren’t far behind transportation and buildings. The report shows that it’s not enough just to drive less, invest in cleaner electricity, and retrofit buildings for efficiency. To reduce emissions, people also need to buy less stuff.
Or, alternatively, they need to buy stuff that takes less energy to produce. Dow Constantine, the county executive, took a “buy local” message away from the report: It’s “not only good for our economy; it’s good for the planet, as well,” he said in a release. But the reality is more complicated: Transporting, selling, and disposing of the products King County residents consumed accounted for only 15 percent of those goods’ emissions, while production accounted for 60 percent.
King County's low-carbon energy program means making goods locally could reduce the energy required for production. But as the SEI report points out, the hydroelectric resources that keep electricity emissions low are all but tapped out. For local goods to lower production emissions, the county would need new sources of clean energy. Of course, building new power plants, however renewable and clean, comes with its own cost.