Urban scaling of air pollutants in Israel

Abstract 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. Therefore, recently, this methodology of urban scaling has been implemented to study the dynamics of vehicle and industrial emissions into the environment. It has been shown that cities may be environmentally efficient with CO 2 emissions that seem to be sublinear, so the large cities may be more "green". However, a number of reports suggest a superlinear relationship with respect to city size, so the larger cities may be less "green". We report here the results of the nonlinear allometric power-law scaling properties of multiple air pollutants in the Israel urban system, expanding the analysis to include electricity consumption and atmospheric emissions of CO 2 , NO x , SO 2 , CO, NMVOC, PM 10 , PM 2.5 , benzene and 1,3-butadiene. The results show the recurring mathematical patterns of cities similar to those reported elsewhere. Electricity usage is superlinear. Pollutant emissions of these greenhouse gases tend to exhibit significant superlinear dynamics (β > 1), though NMVOC and Benzene were linear. The superlinear result was conserved when regressing against the number of vehicles. This evidence supports the hypothesis that large cities may be less "green". However, 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. With this perspective it may be possible to implement sustainable policy to improve the environment and increase human wellbeing.