Columbia has been one of the most progressive cities in Missouri when it comes to climate change. They were among the first to study their greenhouse gas emissions, and were an early adopter of the U.S. Mayors Climate Protection Agreement. The Columbia City Council passed an ordinance in 2006 committing the city to reducing GHG emissions 7% from 2000 levels by 2012. Columbia became the first municipality in Missouri that I know of to complete an inventory of GHG emissions in three separate years, each 5 years apart: 2000, 2005, and 2010. The most recent update was issued in 2012, though I just became aware of it.

According to the update, Columbia’s total emissions grew by 8.61% between 2000 and 2010. However, the city’s population grew by 26.85% during the same period of time. On a per capita basis, Columbia’s emissions declined by 14.39% from 25.39 MTCO2e per capita to 21.74 MTCO2e.

The first chart at right shows community emissions by sector for 2000, 2005, and 2010. The second chart at right shows per capita emissions. In the charts, the “Other” category includes emissions from wastewater and solid waste.

(Click on charts for larger view)

The data for 2000 and 2005 differ slightly from the data I originally published when I first reported on the Columbia GHG inventory (original post here). The reason is that the new update used improved methods to calculate some of the data, and it standardized the older inventories to the new one. One of the changes involves the use of metric tons of CO2e, where previous inventories used short tons.

In all three years the commercial sector emitted the largest fraction of Columbia’s emissions, followed by the residential and transportation sectors. Across the 10-year period, only emissions from the industrial sector declined, by 15.21%. Transportation emissions increased by 20.90%, residential by 13.10%, and commercial by 10.34%.

If a municipality’s population grows because people moved to the municipality from elsewhere, it may not represent an overall increase in GHG emissions, but rather a relocation of them. However, one cannot be sure without much more analysis, and it brings up a problem that is often omitted in discussing GHG emissions. The amount of GHG emitted per person declined in Columbia, but the effect was overcome by the increase in population. Overall GHG emissions still went up. We (the United States, the World) may make progress in reducing the amount of GHG emitted by each person, but if population continues to grow unchecked, emissions may continue to increase despite our efforts.

Sources:

Mitchell, James. City of Columbia, Missouri Greenhouse Gas Inventory 2010 Update and Emission Reduction Recommendations. http://www.gocolumbiamo.com/Sustainability/documents/MicrosoftWord-ColumbiaGHG2012FINALREPORT.pdf.

For Columbia’s 2000 & 2005 population: Table 4. Annual Estimates of the Resident Population for Incorporated Places in Missouri: April 1, 2000 to July 1, 2009 (SUB-EST2009-04-29). U. S. Census Bureau. https://www.census.gov/popest/data/cities/totals/2009/SUB-EST2009-4.html.

For Columbia’s 2010 population: State & County QuickFacts, U.S. Census Bureau, http://quickfacts.census.gov/qfd/states/29/2915670.html.