Abstracts for the 2011 NAEMSP Scientific Assembly

Abstract

[Extract] Background. With mounting insecurity over domestic fuel supplies and public pressure to reduce environmental pollution, it is essential that emergency medical services (EMS) systems have valid energy use data to make evidence-based decisions on system sustainability and fuel shortage contingency planning. Previous research has demonstrated that EMS systems routinely collect energy consumption data needed to calculate greenhouse gas emissions directly produced by their operations (a Tier 2 carbon footprint), and has quantified emissions from a sample of North American EMS systems. Those previous efforts, however, depended in part on estimated data. Objective. The purpose of this secondary analysis was to explore the extent to which the previously reported carbon footprint data relied on estimated energy consumption, which may have artificially inflated reported greenhouse gas emissions. Methods. Fifteen diverse North American EMS systems previously provided energy consumption data, with 10 systems providing complete Tier 2 carbon footprint data for a full year. Data forms were reviewed to determine the proportion of overall emissions produced from estimated versus directly measured energy consumption among the 10 systems providing complete Tier 2 data. Results. Of the 30,627,046 pounds of carbon dioxide equivalents (CO2e) produced by the 10 services, 96.5%% arose from measured energy consumption and 1.8%% arose from estimated energy consumption; the nature of the source data for 1.8%% of the reported energy consumption could not be determined. Emission sources that contributed most to the EMS carbon footprint were also the sources with the highest proportion of direct measurement, including diesel fuel (99.5%% measured), natural gas (98.7%% measured), gasoline (90.1%% measured), and electricity (88.4%% measured). Liquid propane (31.3%% measured), business air travel (23.5%% measured), and compressed natural gas (0.0%% measured) were the most frequently estimated energy sources, but these accounted for less than 1%% of the previously reported EMS carbon footprint. Conclusion. A high proportion of the energy consumption data incorporated into the previously reported EMS carbon footprint are directly measured, not estimated. This suggests that data informing the calculated EMS-related greenhouse gas emissions are valid, and that estimated energy consumption more likely resulted in underrepresentation, rather than overrepresentation, of the carbon footprint of North American EMS systems.