Model

Top Chemicals in the Model

This study’s linear regression model aims to quantify the relationship between chemical concentrations and greenhouse gas emissions. The regression equation contains a similar generalized form:

\[ \log(1 + \text{Emissions}_{\mathrm{mt}}) = \beta_0 + \sum_{j} \beta_j \cdot \text{Chemical}_j + \sum_{k} \gamma_k \cdot \text{Facility}_k + \sum_{l} \delta_l \cdot \text{Year}_l + \epsilon \]

Where B_o is the constant term, which represents the baseline level of emissions when all chemicals’ concentrations are zero. In other words, B_o provides the starting point of emissions, independent of any chemical’s influence. The coefficients (B_1, B_2, etc.) represent the strength of the relationship between each chemical’s concentration and the log-transformed emissions.

Chemical Coefficients
Variable..Chemical.Name. Coefficient
Trifluoroethylene 7.52
PFC-14 (Perfluoromethane) 2.84
Chlorodifluoromethane 2.29
HFC-152a 2.27
Perfluoro(methylcyclopropane) 2.24
HFC-1132a; VF2 2.22
HFC-32 2.19
HFC-134a 2.07
1H,10H-Perfluorodecane 2.05
Perfluorocyclobutane 2.01

The fitted regression model identified Trifluoroethylene, PFC-14 (Perfluoromethane), and Chlorodifluoromethane as the most influential chemicals contributing to increased log-transformed emissions, with estimated coefficients of 7.52, 2.84, and 2.29, respectively. These values indicate a strong association between the presence of these chemicals and higher reported greenhouse gas emissions at the facility level.