No abstract

Seventy-five diesel vehicles were measured in China using a portable emissions measurement system (PEMS). Particular matter (PM) emission factors and gaseous emission factors for Euro 0 (E0), Euro 1 (E1), Euro 2 (E2), and Euro 3 (E3) trucks were obtained under highway, urban, and rural driving conditions. Vehicle emission regulations in China have successfully reduced carbon monoxide (CO), hydrocarbons (HC) and PM by 62, 56, and 72% on average. Most of the emission reductions were achieved when the control technology went from E0 to E1 in Xi'an, and E2 to E3 in Beijing, which resulted in PM reductions of 79% associated with highway driving and 60% associated with urban or rural driving. Emission levels of oxides of nitrogen (NO(X)) were not improved from previous emission control steps. Compared with Xi'an, the emission rate is lower in Beijing, which is strong evidence of the effectiveness of the present comprehensive emission control strategy in Beijing. Emissions were grouped into driving bins that corresponded to the energy demand placed on the vehicles. By using this binning approach, it was found that E3 trucks were successfully controlling the high emission rates in aggressive driving bins, which led to the low average emission for E3 trucks.

Worldwide, urbanization constitutes a major and growing driver of global change and a distinctive feature of the Anthropocene. Thus, urban development paths present opportunities for technological and societal transformations towards energy efficiency and decarbonization, with benefits for both greenhouse gas (GHG) and air pollution mitigation. This requires a better understanding of the intertwined dynamics of urban energy and land use, emissions, demographics, governance, and societal and biophysical processes. In this study, we address several characteristics of urbanization in Santiago (33.5°S, 70.5°W, 500 m a.s.l.), the capital city of Chile. Specifically, we focus on the multiple links between mobility and air quality, describe the evolution of these two aspects over the past 30 years, and review the role scientific knowledge has played in policy-making. We show evidence of how technological measures (e.g., fuel quality, three-way catalytic converters, diesel particle filters) have been successful in decreasing coarse mode aerosol (PM10) concentrations in Santiago despite increasing urbanization (e.g., population, motorization, urban sprawl). However, we also show that such measures will likely be insufficient if behavioral changes do not achieve an increase in the use of public transportation. Our investigation seeks to inform urban development in the Anthropocene, and our results may be useful for other developing countries, particularly in Latin America and the Caribbean where more than 80% of the population is urban.

The changing composition of the atmosphere, driven by anthropogenic emissions, is the cause of anthropogenic climate change as well as deteriorating air quality. Emission inventories are essential to understand the contribution of various human activities, model and predict the changing atmospheric composition, and design cost-effective mitigation measures. At present, national emission inventories in South America (SA) focus on Greenhouse Gases (GHG) as part of their obligations to the United Nations Framework Convention for Climate Change (UNFCC) within the framework of their national communications. Emission inventories other than for GHG in SA focus mainly on growing urban areas and megacities. Therefore, studies examining air quality at national, regional or continental scales in SA depend on (down-scaled) global emission inventories. This paper examines the emission estimates of air pollutants from various global inventories for five SA countries, namely Argentina, Brazil, Chile, Colombia and Peru. A more detailed analysis is conducted for the EDGAR and ECLIPSE emission inventories, in particular against local city-scale inventories of a major city in each country. Although total emissions between down-scaled global inventories and local city inventories are often comparable, large discrepancies exist between the sectoral contributions. This is critical as the mitigation of poor air quality will depend on addressing the right sources. Potential sources of discrepancies between global and local inventories include the spatial distribution proxies, difference in emission factors used and/or the use of generic statistical country data when estimating emissions. This highlights the importance of using local information when generating national emission inventories, especially for air quality modeling and development of effective mitigation measures. This work represents a first step towards an increased understanding of the strength and weaknesses of emissions information in SA.