Search

Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation – the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground – this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies – lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies’ performance, are discussed together with policy implications to narrow those gaps. [ABSTRACT FROM AUTHOR]

Abstract: Methane is a potent greenhouse gas, 21 times as powerful as carbon dioxide in contributing to climate change on a ton-for-ton basis. Methane, along with other short-lived forcers such as black carbon and tropospheric ozone, could play an important role in addressing global climate change. This stems both from their overall effect on climate systems, and from their concentrated impact in the short term. Because reducing emissions of such short-lived pollutants may have a large near-term impact in slowing climate change, the United States and other countries have come together to cooperate under the Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants, and other partnerships such as the Global Methane Initiative. For global impact, the success of such partnerships depends on their ability to scale up project-specific emission reductions. This paper assesses options and challenges for scaling based on a case study of Russia's oil and gas sector. We examine the challenges to achieving far-reaching emission reductions, successes of companies to date, how Russia has sought to influence methane emissions through its environmental fine system, and options for helping companies achieve large-scale emission reductions in the future through simpler and clearer incentives. [Copyright &y& Elsevier]

Abstract: The uncertain, future development of emissions of short-lived trace gases and aerosols forms a key factor for future air quality and climate forcing. The Representative Concentration Pathways (RCPs) only explore part of this range as they all assume that worldwide ambitious air pollution control policies will be implemented. In this study, we explore how different assumptions on future air pollution policy and climate policy lead to different concentrations of air pollutants for a set of RCP-like scenarios developed using the IMAGE model. These scenarios combine low and high air pollution variants of the scenarios with radiative forcing targets in 2100 of 2.6 W m−2 and 6.0 W m−2. Simulations using the global atmospheric chemistry and transport model TM5 for the present-day climate show that both climate mitigation and air pollution control policies have large-scale effects on pollutant concentrations, often of similar magnitude. If no further air pollution policies would be implemented, pollution levels could be considerably higher than in the RCPs, especially in Asia. Air pollution control measures could significantly reduce the warming by tropospheric ozone and black carbon and the cooling by sulphate by 2020, and in the longer term contribute to enhanced warming by methane. These effects tend to cancel each other on a global scale. According to our estimates the effect of the worldwide implementation of air pollution control measures on the total global mean direct radiative forcing in 2050 is +0.09 W m−2 in the 6.0 W m−2 scenario and −0.16 W m−2 in the 2.6 W m−2 scenario. [Copyright &y& Elsevier]

Abstract: Ground-level ozone is a secondary pollutant that causes serious health and environmental damage. One of the main challenges in controlling ground-level ozone is to identify the categories of ozone precursor species that contribute the most to ozone levels, and the regions from which they are emitted. In this study, we apply a photochemical model source apportionment tool to identify the contributions of various precursors to seasonal ozone levels in Hong Kong (HK) and the Pearl River Delta (PRD) region, according to their source regions and categories. We establish a full precursor contribution matrix for the ozone concentrations in all cities within the HK/PRD region. This matrix can be used to rank the relative importance of precursors by source region/category for each city. It can also be used to show how the precursor emissions from any city/category affect ozone levels in neighboring cities. The results show substantial seasonal variation in the source contributions from the HK/PRD region. During ozone episodes, precursors from the region accounted for 68–80% of ozone concentrations in July and 35–55% in October, but only 19–32% in January and April. For all of the cities in the PRD, the top three precursor categories contributing to ozone episodes were mobile, point and area sources. Biogenic and point sources were more important in July than in October. In contrast, the ranking of contributing source regions showed considerable variation across cities and seasons, implying substantial variations in the ways in which precursors from one city affect ozone levels in neighboring cities. Our results show that source contribution and impact analysis can be very useful for evaluating the ozone control strategies of local governments. For the PRD region, a local reduction in mobile, area and point sources, together with regional collaborations on pollution control, are of particular importance in effectively reducing episodic ozone concentrations. [Copyright &y& Elsevier]

Abstract: In recent years, heavy metal pollution accidents were reported frequently in China. The atmospheric heavy metal pollution is drawing all aspects of attention. This paper summarizes the recent research results from our studies and previous studies in recent years in China. The level, temporal variation, seasonal variation and size distribution of the heavy metals of atmospheric Lead(Pb), Vanadium(V), Manganese(Mn), Nickel(Ni), Chromium(Cr), Cadmium(Cd), Copper(Cu), Zinc(Zn) and Arsenic(As) were characterized in China. The emission characteristics and sources of atmospheric heavy metals and As in China were reviewed. Coal burning, iron and steel industry and vehicle emission are important sources in China. Control policies and effects in China were reviewed including emission standards, ambient air quality standards, phase out of leaded gasoline and so on, and further works for atmospheric heavy metals control were suggested. The comprehensive heavy metals pollution control measures and suggestions were put forward based on the summarization of the development and experience of the atmospheric heavy metal pollution control abroad. [Copyright &y& Elsevier]

Abstract: To reduce air pollution levels in Santiago, Chile on days when the weather is expected to create poor ventilation conditions and increased air pollutant concentrations, the responsible authorities impose temporary restrictions on motor vehicles and certain industrial activities. We estimate the impact of these restrictions on the city''s air quality using data collected by a network of monitoring stations. The estimates show that the restrictions do reduce the average concentrations of coarse and fine particulate matter, carbon monoxide and nitrogen oxide (both gases are emitted mainly by vehicles). However, no significant changes were found in the sulfur dioxide concentrations, which are primarily the result of industrial processes. [Copyright &y& Elsevier]

Abstract: Air quality progress in the North American megacities of Los Angeles, New York, and Mexico City is reviewed, compared, and contrasted. Enormous progress made in North America over the last 5 decades provides a template for other megacities of the world, especially in developing countries, attempting to achieve rapid economic growth without compromising air quality. While the progress to date has been impressive, many challenges remain including the need to improve air quality while simultaneously mitigating climate change. The impact of pollutant emissions from megacities is felt long distances away from the local sources but no policy mechanisms currently exist to mitigate air quality impacts resulting from such pollution transport. [Copyright &y& Elsevier]

Abstract: While adaptation to climate change is primarily thought of as a water, weather, and infrastructure issue, air quality and air quality management are important aspects of climate change adaptation. Air quality and climate change are so heavily intertwined that air quality needs to be considered not only for mitigation strategies but also in management of and adapting to climate change. [Copyright &y& Elsevier]