Greenhouse Gas Inventories Help Cities Reduce Emissions

Cities have been rolling out programs to shrink their carbon footprint and reduce greenhouse gas emissions for years. Yet, there has been minimal validation to see if the efforts make a difference. A new study at the University of Kansas reveals that having a greenhouse gas (GHG) emissions inventory makes a big difference in helping cities reduce carbon emissions.

The research indicates that those municipalities that took GHG emissions inventories experienced significant declines in fossil fuel-derived CO2 emissions relative to non-inventory communities. The study, which was conducted by Rachel Krause, a professor of public affairs and administration at KU, illustrates the role played by such inventories in furthering local-level sustainability.

We discovered proof that the development and building of a GHG emissions inventory was causally associated with reduced fossil fuel carbon dioxide emissions," Krause explained. "Inventories indicate extensive inquiry into the source and quantity of local emissions, and we speculate that this knowledge enhances the capacity to manage efforts and permit change.

Although "sustainability" is a wide umbrella that can cover all manner of municipal initiative, the study targeted two types of practices commonly undertaken: emissions inventorying and the employment of sustainability personnel in city governments. The intention was to examine the efficacy of both practices toward the reduction of emissions, a topic which has been somewhat in the dark.

To carry out the study, researchers compared data from cities throughout the United States, determining whether they had an emissions inventory or sustainability staff in 2010 and 2015. Only municipalities that did not have these in place in 2010 were included in the analysis so that any emission changes could be linked to their implementation. This gave a sample of 702 municipalities for the analysis of emissions inventory and 484 for the sustainability staff assessment.

Satellite-collected data were used by the researchers to estimate emissions changes. They estimated emissions inside city limits and then compared reductions in cities where these were done with cities that did not take them into account.

The results indicated that cities that undertook a GHG emissions inventory experienced a statistically significant decrease in CO2 emissions. On average, there was a decline of about 22 pounds of emissions per capita, with the largest decreases attributed to residential emissions. This indicates that the process of tracking the source of emissions enables cities to have focused approaches that result in tangible progress.

Nevertheless, the research could not identify a statistically significant relationship between adding sustainability staff and reductions in emissions. In spite of this, Krause highlighted that the findings do not indicate that sustainability staff are useless or unimportant. "Sustainability can be interpreted in many ways, and because the study could not determine that the addition of staff leads to less emissions, does not necessarily mean they have not had an impact on other meaningful improvements," she added.

The research was co-authored by Angela Park, a KU public affairs graduate and employee at the KDI School of Public Policy and Management in South Korea; Christopher Hawkins of the University of Central Florida; and Aote Xin of Claremont Graduate University. The research appeared in the journal Cities.

The results inform part of an argument regarding the efficacy of local climate action. Some critics suggest that local efforts are too minor to have a serious impact on aggregate emissions because there are larger determinants such as national policy, economic conditions, and climate fluctuations that drive change. The current research, though, presents data to inform that local efforts—specifically emissions inventories—are not insignificant.

It's not going to fix the problem, but is there any indication that these planning and accounting efforts are moving the needle in the right direction? We're finding that the answer is yes, they are," Krause said. "I argue that means something.

As national and international climate policies continue to evolve, cities are expected to remain at the forefront of addressing greenhouse gas emissions. While large-scale changes are necessary to combat climate change effectively, this research suggests that local investments in data collection and planning can contribute to meaningful progress.

With increasing pressure on governments to act on climate change, research such as this provides useful evidence on what cities can do to contribute. The study highlights the value of emissions inventories as a means by which cities can monitor, make sense of, and ultimately curb their carbon emissions. As local authorities seek methods for improving their own sustainability efforts, this research clearly demonstrates that compiling emissions information is an important first step in making genuine environmental strides.