Atmospheric Emissions

A new methodology is developed to constrain
Chinese anthropogenic emissions of nitrogen oxides (NOx)
from four major sectors (industry, power plants, mobile and
residential) in July 2008. It combines tropospheric NO2 column
retrievals from GOME-2 and OMI, taking advantage
of their different passing time over China (10:00 a.m. LT
(local time) versus 02:00 p.m.) and consistent retrieval algorithms.
The approach is based on the difference of NOx
columns at the overpass times of the two instruments; it thus
is less susceptible to the likely systematic errors embedded
in individual retrievals that are consistent with each other.
Also, it explicitly accounts for diurnal variations and uncertainties
of NOx emissions for individual sources. Our best
top-down estimate suggests a national budget of 6.8 TgN/yr
(5.5 TgN/yr for East China), close to the a priori bottom-up
emission estimate from the INTEX-B mission for the year of
2006. The top-down emissions are lower than the a priori
near Beijing, in the northeastern provinces and along the east
coast; yet they exceed the a priori over many inland regions.
Systematic errors in satellite retrievals are estimated to lead
to underestimation of top-down emissions by at most 17%
(most likely 10%). Effects of other factors on the top-down
estimate are typically less than 15% each, including lightning,
soil emissions, mixing in planetary boundary layer, anthropogenic
emissions of carbon monoxide and volatile organic
compounds, magnitude of a priori emissions, assumptions
on emission diurnal variations, and uncertainties in the
four sectors. The a posteriori emission budget is 5.7 TgN/yr
for East China.

Field measurements and data investigations were conducted for developing an emission factor database for inventories of atmospheric pollutants from Chinese coal-fired power plants. Gaseous pollutants and particulate matter (PM) of different size fractions were measured using a gas analyzer and an electric low-pressure impactor (ELPI), respectively, for ten units in eight coal-fired power plants across the country. Combining results of field tests and literature surveys, emission factors with 95% confidence intervals (CIs) were calculated by boiler type, fuel quality, and emission control devices using bootstrap and Monte Carlo simulations. The emission factor of uncontrolled SO₂ from pulverized combustion (PC) boilers burning bituminous or anthracite coal was estimated to be 18.0S kg t⁻¹ (i.e., 18.0 × the percentage sulfur content of coal, S) with a 95% CI of 17.2S–18.5S. NO_X emission factors for pulverized-coal boilers ranged from 4.0 to 11.2 kg t⁻¹, with uncertainties of 14–45% for different unit types. The emission factors of uncontrolled PM_2.5, PM₁₀, and total PM emitted by PC boilers were estimated to be 0.4A (where A is the percentage ash content of coal), 1.5A and 6.9A kg t⁻¹, respectively, with 95% CIs of 0.3A–0.5A, 1.1A–1.9A and 5.8A–7.9A. The analogous PM values for emissions with electrostatic precipitator (ESP) controls were 0.032A (95% CI: 0.021A–0.046A), 0.065A (0.039A–0.092A) and 0.094A (0.0656A–0.132A) kg t⁻¹, and 0.0147A (0.0092–0.0225A), 0.0210A (0.0129A–0.0317A), and 0.0231A (0.0142A–0.0348A) for those with both ESP and wet flue-gas desulfurization (wet-FGD). SO₂ and NO_X emission factors for Chinese power plants were smaller than those of U.S. EPA AP-42 database, due mainly to lower heating values of coals in China. PM emission factors for units with ESP, however, were generally larger than AP-42 values, because of poorer removal efficiencies of Chinese dust collectors. For units with advanced emission control technologies, more field measurements are needed to reduce emission factor uncertainties.

China's rapid economic growth has been accompanied by a high level of environmental degradation. One of the major sources of health and ecosystem damages is sulfur dioxide (SO₂). Reducing SO₂ emissions is a priority of China's environmental authorities, and the 11th Five-Year Plan (2006–2010) includes the target of reducing total SO₂ emissions by 10 percent from the 2005 level. Given the rapid increase in SO₂ emissions that is expected to occur in absence of intervention, attaining this target will require a significant effort. This article examines the two major policy measures the government is taking to achieve the SO₂ target: a shutdown of many small, inefficient power plants and the installation of desulfurization equipment on existing and new coal-fired plants. We present results from a joint U.S.–China study that we participated in, which estimated the costs and benefits of these policies. We then estimate the economy-wide impacts of the two policies using a multisector model of the Chinese economy. We find that in the aggregate, the economic benefits of the shutdown of the small power plants are large enough to offset the costs of the desulfurization equipment, even without considering the substantial environmental benefits from the reduction of emissions of SO₂ and other pollutants.

Facing challenges of increased energy consumption and related regional air pollution, China has been aggressively implementing flue gas desulfurization (FGD) and phasing out small inefficient units in the power sector in order to achieve the national goal of 10% reduction in sulfur dioxide (SO₂) emissions from 2005 to 2010. In this paper, the effect of these measures on soil acidification is explored. An integrated methodology is used, combining emission inventory data, emission forecasts, air quality modeling, and ecological sensitivities indicated by critical load. National emissions of SO₂, oxides of nitrogen (NO_X), particulate matter (PM), and ammonia (NH₃) in 2005 were estimated to be 30.7, 19.6, 31.3, and 16.6 Mt, respectively. Implementation of existing policy will lead to reductions in SO₂ and PM emissions, while those of NO_X and NH₃ will continue to rise, even under tentatively proposed control measures. In 2005, the critical load for soil acidification caused by sulfur (S) deposition was exceeded in 28% of the country’s territory, mainly in eastern and south-central China. The area in exceedance will decrease to 26% and 20% in 2010 and 2020, respectively, given implementation of current plans for emission reductions. However, the exceedance of the critical load for nitrogen (N, combining effects of eutrophication and acidification) will double from 2005 to 2020 due to increased NO_X and NH₃ emissions. Combining the acidification effects of S and N, the benefits of SO₂ reductions during 2005−2010 will almost be negated by increased N emissions. Therefore abatement of N emissions (NO_X and NH₃) and deposition will be a major challenge to China, requiring policy development and technology investments. To mitigate acidification in the future, China needs a multipollutant control strategy that integrates measures to reduce S, N, and PM.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

Based on the application of a Consumer Lifestyle Approach (CLA), this paper quantifies the direct and indirect impact of lifestyle of urban and rural residents on China's energy use and the related CO₂ emissions during the period 1999–2002. The results show that approximately 26 per cent of total energy consumption and 30 per cent of CO₂ emission every year are a consequence of residents’ lifestyles, and the economic activities to support these demands. For urban residents the indirect impact on energy consumption is 2.44 times greater than the direct impact. Residence; home energy use; food; and education, cultural and recreation services are the most energy-intensive and carbon-emission-intensive activities. For rural residents, the direct impact on energy consumption is 1.86 times that of the indirect, and home energy use; food; education, and cultural recreation services; and personal travel are the most energy-intensive and carbon-emission-intensive activities. This paper provides quantitative evidence for energy conservation and environmental protection focused policies. China's security for energy supply is singled out as a serious issue for government policy-makers, and we suggest that government should harmonize the relationships between stakeholders to determine rational strategies.

Low-energy efficiency and environmental pollution have long been taken as key problems of Chinese industry, although a number of command-and-control and economic instruments have been adopted in the last few decades. In this paper, policy and legislation development for voluntary agreements were summarized. The voluntary agreements pilot project in two iron and steel companies in Shandong Province as well as other cases were analyzed. In order to identify the existing problems in Chinese cases, comparison was made between China and industrialized countries in the practices of energy efficiency voluntary agreements. Based on the analysis, detained recommendations, including the use of supporting policies for voluntary agreements, were raised. It is expected that voluntary agreements could play a more important role in energy efficiency improvement of Chinese industry.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

Observations of tropospheric column densities of NO₂ obtained from the Global Ozone Monitoring Experiment (GOME) for a 3‐year period (1997, 1998, and 2000) are used to derive average seasonal variations in surface emissions of NO_x from east China (100–123°E, 20–42°N). The retrieval allows for zonal variations in the contribution of the stratosphere to the NO₂ column and removes a bias of ±10% on the seasonality of retrieved columns introduced by cloud screening. The top‐down inventory is constructed using an inversion approach with a global 3‐D chemical transport model (GEOS‐Chem) and combined subsequently with the a priori inventory to develop an a posteriori inventory. The contribution of background NO₂ arising from nonsurface sources (lightning) and long‐range transport of emissions originating outside of east China is accounted for in the inversion. The a posteriori estimate of overall emissions for east China, 4.66 Tg N/yr (±30% uncertainty), is 33% higher than the a priori value and is shown to improve agreement with surface measurements of nitrate wet deposition and concentrations of NO_y observed in China. On the basis of multiple constraints on the spatial and seasonal variations of combustion and microbial processes, the a posteriori inventory is partitioned among emissions from biomass burning, fuel combustion, and microbial activity (or soil emissions). Emission of NO_x from biomass burning in east China is estimated as 0.08 TgN/yr ± 50% in the a posteriori inventory, increased by about a factor of 2 from the a priori estimate. The resulting a posteriori inventory for fuel combustion (3.72 TgN/yr ± 32%) is about 15% higher than the a priori and exhibits a distinct maximum in winter, in contrast to the weak seasonality indicated in the a priori inventory. The a posteriori value for the microbial source of NO_x (0.85 TgN/yr ± 40%) is about a factor of 3 higher than the a priori value, amounting to 23% of combustion sources for east China and significantly higher than a priori value of 7%. The microbial source is unimportant in winter. It peaks in summer, accounting for as much as 43% of the combustion source for that season, and is significant also in spring and fall. This seasonality is attributed to the timing of fertilizer application and to the influence of seasonally variable environmental factors including temperature and precipitation.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

An interdisciplinary, quantitative assessment of the health and economic costs of air pollution in China, and of market-based policies to build environmental protection into economic development.

In this study we use Divisia index approach to identify key factors affecting CO₂ emission changes of industrial sectors in Taiwan. The changes of CO₂ emission are decomposed into emission coefficient, energy intensity, industrial structure and economic growth. Furthermore, comparisons with USA, Japan, Germany, the Netherlands and South Korea are made to have a better understanding of emission tendency in these countries and to help formulate our CO₂ reduction strategies for responding to the international calls for CO₂ cuts. The results show that economic growth and high energy intensity were two key factors for the rapid increase of industrial CO₂ emission in Taiwan, while adjustment of industrial structure was the main component for the decrease. Although economic development is important, Taiwan must keep pace with the international trends for CO₂ reduction. Among the most important strategies are continuous efforts to improve energy intensity, fuel mix toward lower carbon, setting targets for industrial CO₂ cuts, and advancing green technology through technology transfer. Also, the clean development mechanism (CDM) is expected to play an important role in the future.

This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 × 10^− 5), followed by sulfur dioxide (5 × 10^− 6), sulfate from sulfur dioxide (4 × 10^− 6), and nitrate from nitrogen oxides (4 × 10^− 6). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R² between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be estimated with reasonable precision and summarized using simple regression models. The results should be useful for informing future decisions about power-plant locations and controls.

Intake fractions, an emissions-intake relationship for primary pollutants, are defined and are estimated in order to make simple estimates of health damages from air pollution. The sulfur dioxide (SO₂) and total suspended particles (TSP) intake fractions for five cities of China are estimated for the four main polluting industries—electric power generation, mineral (mostly cement) products industry, chemical process industry and metallurgical industry (mainly iron and steel smelting). The Industrial Source Complex Long Term (ISTLT3) model is used to simulate the spatial distribution of incremental ambient concentrations due to emissions from a large sample of site-specific sources. Detailed population distribution information is used for each city. The average intake fractions within 50 km of these sources are 4.4 × 10^- 6 for TSP, and 4.2 × 10^- 6 for SO₂, with standard deviations of 8.15 × 10^- 6 and 9.16 × 10^- 6, respectively. They vary over a wide range, from 10^- 7 to 10^- 5. Although the electric power generation has been the focus of much of the air pollution research in China, our results show that it has the lowest average intake fraction for a local range among the four industries, which highlights the importance of pollutant emissions from other industrial sources. Sensitivity analyses show how the intake fractions are affected by the source and pollutant characteristics, the most important parameter being the size of the domain. However, the intake fraction estimates are robust enough to be useful for evaluating the local impacts on human health of primary SO₂ and TSP emissions. An application of intake fractions is given to demonstrate how this approach provides a rapid population risk estimate if the dose-response function is linear without threshold, and hence can help in prioritizing pollution control efforts.

More than 220 Tg N are processed annually through the global agriculture/animal/human food chain. It is suggested that aerobic denitrification, reduction of nitrite formed in the first stage of nitrification, is an important source not only of global N₂O but also of NO_x. A simple top‐down method indicates a globally averaged yield of 2% for N₂O emitted as a consequence of human disturbances to the global nitrogen cycle. This yield can account not only for the contemporary budget of atmospheric N₂O but also for trends observed over the past 1000 years. The associated microbial source of NO_x is estimated assuming a NO_x/N₂O ratio of 3, consistent with results from a variety of laboratory and field studies. This source is significant, particularly for large developing countries such as China and India for which its contribution is comparable to that from fossil fuel.

This paper assesses the role played by market reforms in shaping the future level and composition of production, energy use, and carbon emissions in China. Arguments have been made that reducing distortions in China's economy through market reforms will lead to energy efficiency improvements and lower carbon emissions in China. However, these arguments are based on partial and not general equilibrium analyses, and therefore overlook the effects of market reforms on economic growth and structural change. The results suggest that further implementation of market reforms could result in a structural shift to less carbon-intensive production and thus lower carbon emissions per unit GDP. However, this fall in carbon intensity is not enough to compensate for the greater use of energy as a result of market reforms due to higher economic growth and changes in the composition of production. Therefore, China's transition to a market economy could result in significantly higher economic growth, energy use, and carbon emissions. These results could have implications for other countries considering or undergoing market transition.