A new analysis of greenhouse gas emissions across three southern Indiana counties — including Bartholomew County — has provided a picture of how the region is contributing to climate change and what local communities can do to help curb emissions.

The analysis, released this week by Project 46, found that Bartholomew, Brown and Monroe counties produced 4.2 million metric tons of carbon dioxide equivalent in 2022 — with gasoline and diesel vehicles and the use of electricity and natural gas in residential and commercial buildings accounting for 70% of emissions.

Carbon dioxide equivalent is a unit of measurement that allows different greenhouse gases to be compared based on how long they remain in the atmosphere and how much heat they can trap, according to the U.S. Environmental Protection Agency.

The analysis also projects that greenhouse gas emissions in the three-county region will decline 33% by 2030 “as a result of projected population growth, vehicle fuel efficiency and electric grid improvements, market conditions and current policies.”

However, the three-county region could reduce greenhouse gas emissions by an additional 6% by the end of the decade if communities implement certain “high-impact actions” — including increasing electric vehicle adoption, conducting energy efficiency retrofits of residential and commercial buildings and diverting waste to composting and recycling instead of landfills.

“The 6% reduction from regional action would be an important contribution in a five-year timeframe, and these actions would also help to accelerate important trends … that would continue to yield larger emissions reductions and benefits after 2030,” according to the analysis, which was conducted by Farallon Strategies and ICLEI – Local Governments for Sustainability. “Implementing these action can also provide additional benefits such as reduced transportation costs, stronger economies and improved health.”

Launched in 2023, Project 46 is a regional climate alliance that includes the cities of Columbus and Bloomington and the town of Nashville and seeks to address the region’s shared challenges and opportunities related to climate change. The project is named after State Road 46, which links the three communities together.

Columbus Mayor Mary Ferdon, who is a member of the project’s steering committee, said city officials are in the initial stages of reviewing the data collected through the analysis to determine what actions could be taken locally.

Next, the city’s internal sustainability committee, which is comprised of several department heads, hopes to establish goals and determine what metrics can be used to track progress, Ferdon said.

“Now we feel like we have some baseline data for all of the Project 46 region … that we can work from and start looking at actions from the city’s perspective,” Ferdon said. “…Our hope is to take some of the recommendations and start looking at what are actions that we can take to move the needle and are measurable. …A lot of the work that I think is going to come out of Project 46 — and it’s still in its infancy — is that each of the three communities will look at it differently. Obviously, Bloomington has a larger population in Columbus, and we both have larger populations than Nashville.”

The analysis found that the transportation sector was the largest source of greenhouse gas emissions in the three-county area in 2022, accounting for 36%, driven mainly by gasoline-powered passenger vehicles, diesel freight traffic and off-road diesel equipment.

Residential energy use was the second-largest contributor at 20%, followed by commercial energy at 15% and industrial energy at 14%. Most of the emissions in those sectors stem from electricity use, with natural gas as the next biggest source.

The remaining 15% came from solid waste, water and wastewater, process and fugitive emissions, agriculture, forestry and other land use, according to the analysis. The major remaining contributing activities are the generation of waste by residents in the three-county area and the release of hydrofluorocarbon and refrigerants through activities ranging from air conditioning to solvent use.

The analysis also estimates that increased electric vehicle (EV) adoption has the potential to be the largest contributor to the estimated additional 6% decrease in emissions that the area could see by the end of the decade, followed by energy efficiency improvements to residential and commercial buildings and water diversion by reducing landfill waste and increasing composting and recycling.

The analysis states that a 10% reduction in vehicle miles traveled by gasoline and diesel-powered vehicles by 2030 and supporting EV adoption could results in a combined decrease in 117,732 metric tons of carbon dioxide equivalent. It also sets a broader potential target of net zero emissions by 2050.

Ferdon said all of the goals in the analysis are “worth looking at” but added that each community may take different actions based on what is feasible for them.

“These are goals that at this initial stage we are looking at,” Ferdon said. “Do they make sense? Are they feasible? That’ll be determined over time. From our perspective, we just got this data, and the city will look at it and see what goals are most applicable to the city of Columbus and the actions that we can take as a city and that we can encourage our businesses and our residents to take.”

While EV adoption has grown in Bartholomew County in recent years, EVs remain a small percentage of all registered vehicles, according to the Indiana Office of Energy Development.

In 2024, 435 EVs were registered in Bartholomew County — the highest total on record and a nearly 11-fold increase since 2018. However, EVs still accounted for less than 1% of all registered vehicles in the county.

Additionally, 2,200 hybrid vehicles were registered in Bartholomew County in 2024 — also the highest annual tally on record and more than double than in 2018.

Bartholomew County is on pace to see the number and share of EVs and hybrids registered increase to record levels this year, going from 1 in 100 vehicles in 2018 to 1 in 25 vehicles so far this year.

As of Aug. 21, EVs and hybrid vehicles had accounted for 4% of all vehicles registered in Bartholomew County this year, up from 3% last year and 1% in 2018. By comparison, EVs and hybrid vehicles accounted for 7% of all vehicles registered in Monroe County from Jan. 1 to Aug. 21, while they represented 3% of all vehicles registered in Brown County.

Besides recommendations for reducing emissions, the analysis also found that “precipitation patterns have changed” over the past few decades, with the Midwest seeing an increase of 5% to 15% in precipitation levels between 1992 and 2021. By 2025, precipitation levels in the Midwest are projected to increase by another 8% to 20%.

In April, Bartholomew County experienced its largest flood in 17 years after 7.5 inches of rain fell in the county in just 36 hours and heavy rainfall in communities north of Bartholomew County resulted in East Fork White River cresting higher than expected.

Ferdon said she expects city officials to focus on building resilience to climate change.

“What I’m intrigued at most is how do we build a more resilient community as we move forward in looking at reducing costs and then trying to prepare for more weather events, which seem to impact us a lot,” Ferdon said. “…With bad weather, with hotter-than-normal summers or colder winters, when we have more snowstorms and more heat waves and drought, what are some actions we can take so that they can protect their homes, protect their yards, their businesses? From my perspective, that’s really the next phase. …The flooding that occurred this spring, we can’t prevent that, but we can predict it much better than we used to be able to. What are some measures that we can take around stormwater? What are measures that we can take to our residents to better protect their homes for events like that?”

“Our understanding is that each community will deal with resiliency differently,” Ferdon added. “These are very broad goals, and I think over time, we’re going to look at them and see which ones are most feasible, that will make sense, and what could actually move the needle.”
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