Tompkins County releases 2024 greenhouse gas inventory; transportation and renewables highlighted

Tompkins County officials on May 7 presented the county’s 2024 greenhouse gas inventory, outlining where emissions come from and how methodological shifts change year‑to‑year comparisons. Terry Carroll of Planning and Sustainability said government operations emitted 4,464 metric tons of carbon dioxide equivalent in 2024 and the broader community total was roughly 1,642,234 metric tons CO2e.

The inventory uses a New York State–guided approach to include upstream and downstream emissions for fossil fuels, Carroll said, which prompted staff to track consumptive units (therms, gallons, and kilowatt‑hours) rather than rely solely on retrospective recalculation of metric tons. “We emitted 4,464 metric tons in the year of 2024,” Carroll said, and the new method lets the county compare concrete fuel consumption across years while aligning with state methodology.

Why it matters: the report is intended to inform a forthcoming climate action plan and to help the county prioritize decarbonization efforts. Transportation and on‑site fuel use are the leading sources for government operations; vehicles and equipment (highway trucks, sheriff’s vehicles, heavy‑duty equipment) remain the largest contributors, followed by buildings and employee commuting.

Key findings and context

- Government operations: 4,464 metric tons CO2e for calendar year 2024, with vehicles and equipment as the primary source. The inventory for the first time included an employee commute survey to capture commuting emissions.

- Community emissions: staff reported a community total near 1,642,234 metric tons CO2e, with the largest sectors being transportation, agricultural livestock, and industry; Cornell’s power plant and campus were placed in an industrial category rather than singled out separately.

- Methodology shifts: staff moved to the state’s upstream/downstream framework to allow apples‑to‑apples comparisons across municipalities and to include a fuller accounting of methane’s upstream impacts. That methodological change explains large year‑to‑year swings for some fuels: for example, a 309% increase in propane use reflected a calculation change, not a literal tripling of propane consumption.

- Fuel and sector highlights: the airport and some county public‑works facilities showed major natural‑gas reductions after geothermal conversions; vehicle miles traveled increased, and gasoline consumption rose, which staff said likely reflects both methodology differences and real travel increases.

- Renewables: solar generation grew substantially from 2019 to 2024, with commercial/industrial solar up several hundred percent, driven in part by new utility‑scale projects. Carroll noted at least one large‑scale project (Yellow Barn Solar) permitted and more expected to come online before the next inventory cycle.

Questions from committee members focused on comparability, electric‑vehicle adoption and data sources. Haley Dile (Planning and Sustainability) described county filings in the state electric and gas rate case and noted the county’s concern about potential closure of the Ithaca walk‑in center; she offered to circulate the county’s post‑hearing brief.

Next steps

Carroll said the inventory is a starting point for a county climate action plan to run through the coming year, with community engagement and scenario modeling expected to follow. Staff will supply supplemental charts (year‑over‑year kilowatt‑hour comparisons and additional tables) in the final packet and return with further recommendations and outreach plans.