Urban scaling of air pollutants in Israel

Cities have been shown to exhibit empirical scaling behavior where numerous variables of urban performance are allometric, like greenhouse gas emissions. Polluting emissions have negative environmental and health impacts. This paper will elucidate the empirical urban scaling of atmospheric emissions for the Israeli urban system. It has been shown that cities may be environmentally efficient with CO₂ emissions that seem to be sub-linear, so large cities are more “green”. However, other reports suggest a super-linear relationship with respect to population size, so the large cities are less “green”. We report here for the first time the results of the nonlinear allometric power-law properties of multiple air pollutants, expanding the analysis to include electricity consumption and atmospheric emissions of CO₂, NO_x, SO₂, CO, NMVOC, PM₁₀, PM_2.5, Benzene and 1,3-Butadiene together in one study in the case of Israel. They show the recurring mathematical patterns of cities similar to those reported elsewhere. Electricity usage is super-linear. Pollutant emissions of these greenhouse gases tend to exhibit significant super-linear dynamics (β > 1), though NMVOC and Benzene were linear. These results were conserved when regressing against the urban vehicle fleet size. This evidence supports the hypothesis that large cities may be less “green”. Indeed, different urban characteristics such as geography, local climate and weather conditions, population density, may also affect the pollution levels of cities. Taken together these results give evidence to the effect of urban agglomerations on the environment.