Climate Change & Air Pollution

2013
Yuxuan Wang. 2013. “Atmospheric Modeling of Pollutant Concentrations.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 263-289. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Yu Lei. 2013. “Benefits to Human Health and Agricultural Productivity of Reduced Air Pollution.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 291-328. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Clearer Skies Over China: Reconciling Air Pollution, Climate, and Economic Goals
2013. Clearer Skies Over China: Reconciling Air Pollution, Climate, and Economic Goals. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Yu Zhao, Jie Zhang, and Chris P Nielsen. 2013. “The effects of recent control policies on trends in emissions of anthropogenic atmospheric pollutants and CO2 in China.” Atmospheric Chemistry and Physics, 13, Pp. 487-508. Publisher's VersionAbstract

To examine the effects of China’s national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions of anthropogenic SO2, CO, and total primary PM (particulate matter) in 2010 are estimated to have been 89%, 108%, and 87% of those in 2005, respectively, suggesting successful emission control of those species despite fast growth of the economy and energy consumption during the period. The emissions of NOx and CO2, however, are estimated to have increased by 47% and 43%, respectively, indicating that they remain largely determined by the growth of energy use, industrial production, and vehicle populations. Based on application of a Monte-Carlo framework, estimated uncertainties of SO2 and PM emissions increased from 2005 to 2010, resulting mainly from poorly understood average SO2 removal efficiency in flue gas desulfurization (FGD) systems in the power sector, and unclear changes in the penetration levels of dust collectors at industrial sources, respectively. While emission trends determined by bottom-up methods can be generally verified by observations from both ground stations and satellites, clear discrepancies exist for given regions and seasons, indicating a need for more accurate spatial and time distributions of emissions. Limitations of current emission control polices are analyzed based on the estimated emission trends. Compared with control of total PM, there are fewer gains in control of fine particles and carbonaceous aerosols, the PM components most responsible for damages to public health and effects on radiative forcing. A much faster decrease of alkaline base cations in primary PM than that of SO2 may have raised the acidification risks to ecosystems, indicating further control of acid precursors is required. Moreover, with relatively strict controls in developed urban areas, air pollution challenges have been expanding to less-developed neighboring regions. There is a great need in the future for multipollutant control strategies that combine recognition of diverse environmental impacts both in urban and rural areas with emission abatement of multiple species in concert. To examine the effects of China’s national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions of anthropogenic SO2, CO, and total primary PM (particulate matter) in 2010 are estimated to have been 89%, 108%, and 87% of those in 2005, respectively, suggesting successful emission control of those species despite fast growth of the economy and energy consumption during the period. The emissions of NOx and CO2, however, are estimated to have increased by 47% and 43%, respectively, indicating that they remain largely determined by the growth of energy use, industrial production, and vehicle populations. Based on application of a Monte-Carlo framework, estimated uncertainties of SO2 and PM emissions increased from 2005 to 2010, resulting mainly from poorly understood average SO2 removal efficiency in flue gas desulfurization (FGD) systems in the power sector, and unclear changes in the penetration levels of dust collectors at industrial sources, respectively. While emission trends determined by bottom-up methods can be generally verified by observations from both ground stations and satellites, clear discrepancies exist for given regions and seasons, indicating a need for more accurate spatial and time distributions of emissions. Limitations of current emission control polices are analyzed based on the estimated emission trends. Compared with control of total PM, there are fewer gains in control of fine particles and carbonaceous aerosols, the PM components most responsible for damages to public health and effects on radiative forcing. A much faster decrease of alkaline base cations in primary PM than that of SO2 may have raised the acidification risks to ecosystems, indicating further control of acid precursors is required. Moreover, with relatively strict controls in developed urban areas, air pollution challenges have been expanding to less-developed neighboring regions. There is a great need in the future for multipollutant control strategies that combine recognition of diverse environmental impacts both in urban and rural areas with emission abatement of multiple species in concert.

Chris P Nielsen and Mun S Ho. 2013. “Op-ed: Clearing the air in China.” New York Times (Sunday Review), October 27 , Pp. SR4. Publisher's Version
Yu Zhao. 2013. “Primary Air Pollutant Emissions of Coal-Fired Power Plants in China.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 161-202. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Yu Lei, Qiang Zhang, Chris P Nielsen, and Kebin He. 2013. “Primary Air Pollutants and CO2 Emissions from Cement Production in China.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 203-224. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Chris P Nielsen, Mun S Ho, Jing Cao, Yu Lei, Yuxuan Wang, and Yu Zhao. 2013. “Summary: Carbon Taxes for 2013-2020.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 103-157. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Chris P Nielsen, Mun S Ho, Yu Zhao, Yuxuan Wang, Yu Lei, and Jing Cao. 2013. “Summary: Sulfur Mandates and Carbon Taxes for 2006-2010.” In Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals, Pp. 59-102. Cambridge, MA: MIT Press. Publisher's VersionAbstract

A groundbreaking U.S.–Chinese inquiry into the effects of recent air pollution controls and prospective carbon taxes on China's economy and environment.

China's carbon dioxide emissions now outstrip those of other countries and its domestic air quality is severely degraded, especially in urban areas. Its sheer size and its growing, fossil-fuel-powered economy mean that China's economic and environmental policy choices will have an outsized effect on the global environmental future. Over the last decade, China has pursued policies that target both fossil fuel use and atmospheric emissions, but these efforts have been substantially overwhelmed by the country's increasing energy demands. With a billion citizens still living on less than $4,000 per year, China's energy and environmental policies must be reconciled with the goals of maintaining economic growth and raising living standards.

This book, a U.S.–Chinese collaboration of experts from Harvard and Tsinghua University, offers a groundbreaking integrated analysis of China's economy, emissions, air quality, public health, and agriculture. It first offers essential scientific context and accessible summaries of the book's policy findings; it then provides the underlying scientific and economic research. These studies suggest that China's recent sulfur controls achieved enormous environmental health benefits at unexpectedly low costs. They also indicate that judicious implementation of carbon taxes could reduce not only China's carbon emissions but also its air pollution more comprehensively than current single-pollutant policies, all at little cost to economic growth.

Xuan Wang, Yuxuan Wang, Jiming Hao, Yutaka Kondo, Martin Irwin, J. William Munger, and Yongjing Zhao. 2013. “Top-down estimate of China's black carbon emissions using surface observations: Sensitivity to observation representativeness and transport model error.” Journal of Geophysical Research, 118, 11, Pp. 5781-5795. Publisher's VersionAbstract

This study examines the sensitivity of “top-down” quantification of Chinese black carbon (BC) emissions to the temporal resolution of surface observations and to the transport model error associated with the grid resolution and wet deposition. At two rural sites (Miyun in North China Plain and Chongming in Yangtze River Delta), the model-inferred emission bias based on hourly BC observations can differ by up to 41% from that based on monthly mean observations. This difference relates to the intrinsic inability of the grid-based model in simulating high pollution plumes, which often exert a larger influence on the arithmetic mean of observations at monthly time steps. Adopting the variation of BC to carbon monoxide correlation slope with precipitation as a suitable measure to evaluate the model's wet deposition, we found that wet removal of BC in the model was too weak, due in part to the model's underestimation of large precipitation events. After filtering out the observations during high pollution plumes and large precipitation events for which the transport model error should not be translated into the emission error, the inferred emission bias changed from −11% (without filtering) to −2% (with filtering) at the Miyun site, and from −22% to +1% at the Chongming site. Using surface BC observations from three more rural sites (located in Northeast, Central, and Central South China, respectively) as constraints, our top-down estimate of total BC emissions over China was 1.80 ± 0.65 Tg/yr in 2006, 0.5% lower than the bottom-up inventory of Zhang et al. (2009) but with smaller uncertainty.

2012
Yu Zhao, Chris P Nielsen, and Michael B. McElroy. 2012. “China's CO2 emissions estimated from the bottom up: Recent trends, spatial distributions, and quantification of uncertainties.” Atmospheric Environment, 59, Pp. 214-223. Publisher's VersionAbstract
China's emissions of anthropogenic CO2 are estimated using a bottom-up emission inventory framework based on a detailed categorization of economic sectors and provincial economic and energy data. It includes a newly compiled database of CO2 emission factors employing the latest field study results from China. Total annual emissions are estimated to have risen from 7126 to 9370 Mt CO2 from 2005 to 2009. Recent policies to conserve energy and reduce emissions have been effective in limiting CO2 emissions from power and iron & steel plants, but have had little effect on those from cement production. The uncertainties of China's CO2 emissions are quantified for the first time using Monte-Carlo simulation, producing a 95% confidence interval (CI) of −9% to +11% for total emissions in 2005. The largest contributors to sector-level emission uncertainty are emission factors for most industrial sources and activity levels for power plants, transportation, and residential & commercial sources. Application of province-level energy consumption and China-specific emission factors in some sectors results in higher annual emission estimates for 2005-2008 as compared with other studies, although most of those are within the 95% CIs of this study.
Yu Zhao, Chris P Nielsen, Michael B. McElroy, Lin Zhang, and Jie Zhang. 2012. “CO emissions in China: Uncertainties and implications of improved energy efficiency and emission control.” Atmospheric Environment, 49, Pp. 103-113. Publisher's VersionAbstract
A bottom-up methodology and an improved database of emission factors combining the latest domestic field measurements are developed to estimate the emissions of anthropogenic CO from China at national and provincial levels. The CO emission factors for major economic sectors declined to varying degrees from 2005 to 2009, attributed to improved energy efficiency and/or emission control regulations. Total national CO emissions are estimated at 173 Tg for 2005 and have been relatively stable for subsequent years, despite fast growth of energy consumption and industrial production. While industry and transportation sources dominated CO emissions in developed eastern and north-central China, residential combustion played a much greater role in the less developed western provinces. The uncertainties of national Chinese CO emissions are quantified using Monte Carlo simulation at −20% to +45% (95% confidence interval). Due to poor understanding of emission factors and activity levels for combustion of solid fuels, the largest uncertainties are found for emissions from the residential sector. The trends of bottom-up emissions compare reasonably to satellite observation of CO columns and to ground observations of CO2–CO correlation slopes. The increase in the ratio for emissions of CO2 relative to CO suggests that China has successfully improved combustion efficiencies across its economy in recent years, consistent with national policies to improve energy efficiency and to control criteria air pollutants.
Junling Huang and Michael B. McElroy. 2012. “The contemporary and historical budget of atmospheric CO2.” Canadian Journal of Physics, 90, 8, Pp. 707-716. Publisher's VersionAbstract
Observations of CO2 and O2 are interpreted to develop an understanding of the changes in the abundance of atmospheric CO2 that have arisen over the period 1995–2007. Fossil fuels accounted for an addition of 89.3 Gt of carbon to the atmosphere over this time period, 29% of which was transferred to the ocean, 15% to the global biosphere, with the balance (57%) retained by the atmosphere. Analysis of historical data for CO2 derived from studies of gases trapped in ice at Law Dome in Antarctica indicate that the biosphere represented a net source of atmospheric CO2 prior to 1940, switching subsequently to a net sink.
Xi Lu, Jackson Salovaara, and Michael B. McElroy. 2012. “Implications of the recent reductions in natural gas prices for emissions of CO2 from the US power sector.” Environmental Science & Technology, 46, 5, Pp. 3014–3021. Publisher's VersionAbstract
CO2 emissions from the US power sector decreased by 8.76% in 2009 relative to 2008 contributing to a decrease over this period of 6.59% in overall US emissions of greenhouse gases. An econometric model, tuned to data reported for regional generation of US electricity, is used to diagnose factors responsible for the 2009 decrease. More than half of the reduction is attributed to a shift from generation of power using coal to gas driven by a recent decrease in gas prices in response to the increase in production from shale. An important result of the model is that, when the cost differential for generation using gas rather than coal falls below 2–3 cents/kWh, less efficient coal fired plants are displaced by more efficient natural gas combined cycle (NGCC) generation alternatives. Costs for generation using NGCC decreased by close to 4 cents/kWh in 2009 relative to 2008 ensuring that generation of electricity using gas was competitive with coal in 2009 in contrast to the situation in 2008 when gas prices were much higher. A modest price on carbon could contribute to additional switching from coal to gas with further savings in CO2 emissions.

Final Manuscript in DASH
This paper is from a series investigating and comparing the prospects for low- and non-carbon power generation in China and the U.S.; click here (http://news.harvard.edu/gazette/story/2012/02/model-situation/) to see coverage in the Harvard Gazette.

2011
Yuxuan Wang, Xuan Wang, Yutaka Kondo, Mizuo Kajino, J. William Munger, and Jiming Hao. 2011. “Black carbon and its correlation with trace gases at a rural site in Beijing: implications for regional emissions.” Journal of Geophysical Research, 116, D24. Publisher's VersionAbstract
The mass concentrations of black carbon (BC) were measured continuously at Miyun, a rural site near Beijing, concurrently with some trace gases (CO, CO2, NOy, SO2) during the nonheating seasons of 2010 (April to October). The average concentration of BC was 2.26 ± 2.33 μg m−3. About 70%–100% of the air masses arriving at the site from June to September were from the source region of Beijing and the North China Plain (NCP), while in the spring, 40% were of continental background origin. BC had moderate to strong positive correlations with CO (R2 = 0.51), NOy (R2 = 0.58), and CO2 (nonsummer, R2 = 0.54), but not with SO2 (R2 < 0.1). The observed ΔBC/ΔCO ratio was 0.0050 ± 0.0001 μg m−3/ppbv for the regional air masses (excluding the influence of biomass burning). This ratio increased by 68% to 0.0084 ± 0.0004 μg m−3/ppbv after excluding the influence of wet deposition. Accounting further for the impact of atmospheric processes on the observation, we derived an average top‐down BC/CO emission ratio of 0.0095 ± 0.002 μg m−3/ppbv for the source region of Beijing and NCP that is 18%–21% lower than the average emission ratio from the bottom‐up inventory of Zhang et al. (2009), whereas the difference is substantially lower than the uncertainty of emissions for either species. The difference between the mean bottom‐up and top‐down emission ratios is most likely to be attributed to the residential sector, which needs to have a lower share in the total emissions of BC or a much lower BC/CO emission ratio. The industry and transportation sectors are found to be dominant sources of BC from Beijing and the NCP rather than from the residential sector as suggested by the bottom‐up inventory.
Jintai Lin and Michael B. McElroy. 2011. “Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn.” Atmospheric Chemistry and Physics, 11, Pp. 8171-8188. Publisher's VersionAbstract
Rapid economic and industrial development in
China and relatively weak emission controls have resulted in
significant increases in emissions of nitrogen oxides (NOx)
in recent years, with the exception of late 2008 to mid 2009
when the economic downturn led to emission reductions detectable
from space. Here vertical column densities (VCDs)
of tropospheric NO2 retrieved from satellite observations by
SCIAMACHY, GOME-2 and OMI (both by KNMI and by
NASA) are used to evaluate changes in emissions of NOx
from October 2004 to February 2010 identifying impacts of
the economic downturn. Data over polluted regions of Northern
East China suggest an increase of 27–33% in 12-month
mean VCD of NO2 prior to the downturn, consistent with an
increase of 49% in thermal power generation (TPG) reflecting
the economic growth. More detailed analysis is used to
quantify changes in emissions of NOx in January over the
period 2005–2010 when the effect of the downturn was most
evident. The GEOS-Chem model is employed to evaluate
the effect of changes in chemistry and meteorology on VCD
of NO2. This analysis indicates that emissions decreased by
20% from January 2008 to January 2009, close to the reduction
of 18% in TPG that occurred over the same interval. A
combination of three independent approaches indicates that
the economic downturn was responsible for a reduction in
emissions by 9–11% in January 2009 with an additional decrease
of 10%attributed to the slow-down in industrial activity
associated with the coincident celebration of the Chinese
New Year; errors in the estimate are most likely less than
3.4 %.
Yu Lei, Qiang Zhang, Chris P Nielsen, and Kebin He. 2011. “An inventory of primary air pollutants and CO2 emissions from cement production in China, 1990-2020.” Atmospheric Environment, 45, 1, Pp. 147-154. Publisher's VersionAbstract
Direct emissions of air pollutants from the cement industry in China were estimated by developing a technology-based methodology using information on the proportion of cement produced from different types of kilns and the emission standards for the Chinese cement industry. Historical emissions of sulfur dioxide (SO2), nitrogen oxides (NOX), carbon monoxide (CO), particulate matter (PM) and carbon dioxide (CO2) were estimated for the years 1990–2008, and future emissions were projected up to 2020 based on current energy-related and emission control policies. Compared with the historical high (4.36 Tg of PM2.5, 7.16 Tg of PM10 and 10.44 Tg of TSP in 1997), PM emissions are predicted to drop substantially by 2020, despite the expected tripling of cement production. Certain other air pollutant emissions, such as CO and SO2, are also predicted to decrease with the progressive closure of shaft kilns. NOX emissions, however, could increase because of the promotion of precalciner kilns and the rapid increase of cement production. CO2 emissions from the cement industry account for approximately one eighth of China’s national CO2 emissions. Our analysis indicates that it is possible to reduce CO2 emissions from this industry by approximately 12.8% if advanced energy-related technologies are implemented. These technologies will bring co-benefits in reducing other air pollutants as well.
Yu Zhao, Michael B. McElroy, Jia Xing, Lei Duan, Chris P Nielsen, Yu Lei, and Jiming Hao. 2011. “Multiple effects and uncertainties of emission control policies in China: Public health, soil acidification, and global temperature.” Science of the Total Environment , 409, 24, Pp. 5177-5187. Publisher's VersionAbstract
Policies to control emissions of criteria pollutants in China may have conflicting impacts on public health, soil acidification, and climate. Two scenarios for 2020, a base case without anticipated control measures and a more realistic case including such controls, are evaluated to quantify the effects of the policies on emissions and resulting environmental outcomes. Large benefits to public health can be expected from the controls, attributed mainly to reduced emissions of primary PM and gaseous PM precursors, and thus lower ambient concentrations of PM2.5. Approximately 4% of all-cause mortality in the country can be avoided (95% confidence interval: 1–7%), particularly in eastern and north-central China, regions with large population densities and high levels of PM2.5. Surface ozone levels, however, are estimated to increase in parts of those regions, despite NOX reductions. This implies VOC-limited conditions. Even with significant reduction of SO2 and NOX emissions, the controls will not significantly mitigate risks of soil acidification, judged by the exceedance levels of critical load (CL). This is due to the decrease in primary PM emissions, with the consequent reduction in deposition of alkaline base cations. Compared to 2005, even larger CL exceedances are found for both scenarios in 2020, implying that PM control may negate any recovery from soil acidification due to SO2 reductions. Noting large uncertainties, current polices to control emissions of criteria pollutants in China will not reduce climate warming, since controlling SO2 emissions also reduces reflective secondary aerosols. Black carbon emission is an important source of uncertainty concerning the effects of Chinese control policies on global temperature change. Given these conflicts, greater consideration should be paid to reconciling varied environmental objectives, and emission control strategies should target not only criteria pollutants but also species such as VOCs and CO2.
Yu Lei, Qiang Zhang, Kebin He, and David G Streets. 2011. “Primary anthropogenic aerosol emission trends for China, 1990-2005.” Atmospheric Chemistry and Physics, 11, Pp. 931-954. Publisher's VersionAbstract
An inventory of anthropogenic primary aerosol
emissions in China was developed for 1990–2005 using a
technology-based approach. Taking into account changes
in the technology penetration within industry sectors and
improvements in emission controls driven by stricter emission
standards, a dynamic methodology was derived and implemented
to estimate inter-annual emission factors. Emission
factors of PM2.5 decreased by 7%–69% from 1990 to
2005 in different industry sectors of China, and emission factors
of TSP decreased by 18%–80% as well, with the measures
of controlling PM emissions implemented. As a result,
emissions of PM2.5 and TSP in 2005 were 11.0 Tg and
29.7 Tg, respectively, less than what they would have been
without the adoption of these measures. Emissions of PM2.5,
PM10 and TSP presented similar trends: they increased in
the first six years of 1990s and decreased until 2000, then
increased again in the following years. Emissions of TSP
peaked (35.5 Tg) in 1996, while the peak of PM10 (18.8 Tg)
and PM2.5 (12.7 Tg) emissions occurred in 2005. Although
various emission trends were identified across sectors, the cement
industry and biofuel combustion in the residential sector
were consistently the largest sources of PM2.5 emissions,
accounting for 53%–62% of emissions over the study period.
The non-metallic mineral product industry, including the cement,
lime and brick industries, accounted for 54%–63% of
national TSP emissions. There were no significant trends of
BC and OC emissions until 2000, but the increase after 2000
brought the peaks of BC (1.51 Tg) and OC (3.19 Tg) emissions
in 2005. Although significant improvements in the estimation
of primary aerosols are presented here, there still
exist large uncertainties. More accurate and detailed activity
information and emission factors based on local tests are essential
to further improve emission estimates, this especially
being so for the brick and coke industries, as well as for coal.
Yu Zhao, Chris P Nielsen, Yu Lei, Michael B. McElroy, and Jiming Hao. 2011. “Quantifying the uncertainties of a bottom-up emission inventory of anthropogenic atmospheric pollutants in China.” Atmospheric Chemistry and Physics, 11, Pp. 2295-2308. Publisher's VersionAbstract
The uncertainties of a national, bottom-up inventory
of Chinese emissions of anthropogenic SO2, NOx, and
particulate matter (PM) of different size classes and carbonaceous
species are comprehensively quantified, for the first
time, using Monte Carlo simulation. The inventory is structured
by seven dominant sectors: coal-fired electric power,
cement, iron and steel, other industry (boiler combustion),
other industry (non-combustion processes), transportation,
and residential. For each parameter related to emission factors
or activity-level calculations, the uncertainties, represented
as probability distributions, are either statistically fitted
using results of domestic field tests or, when these are
lacking, estimated based on foreign or other domestic data.
The uncertainties (i.e., 95% confidence intervals around the
central estimates) of Chinese emissions of SO2, NOx, total
PM, PM10, PM2.5, black carbon (BC), and organic carbon
(OC) in 2005 are estimated to be −14%13%, −13%37%,
−11%38%, −14%45%, −17%54%, −25%136%,
and −40%121%, respectively. Variations at activity levels
(e.g., energy consumption or industrial production) are
not the main source of emission uncertainties. Due to narrow
classification of source types, large sample sizes, and
relatively high data quality, the coal-fired power sector is estimated
to have the smallest emission uncertainties for all
species except BC and OC. Due to poorer source classifications
and a wider range of estimated emission factors,
considerable uncertainties of NOx and PM emissions from
cement production and boiler combustion in other industries
are found. The probability distributions of emission
factors for biomass burning, the largest source of BC and
OC, are fitted based on very limited domestic field measurements,
and special caution should thus be taken interpreting
these emission uncertainties. Although Monte Carlo simulation
yields narrowed estimates of uncertainties compared
to previous bottom-up emission studies, the results are not
always consistent with those derived from satellite observations.
The results thus represent an incremental research
advance; while the analysis provides current estimates of
uncertainty to researchers investigating Chinese and global
atmospheric transport and chemistry, it also identifies specific
needs in data collection and analysis to improve on
them. Strengthened quantification of emissions of the included
species and other, closely associated ones – notably
CO2, generated largely by the same processes and thus subject
to many of the same parameter uncertainties – is essential
not only for science but for the design of policies to redress
critical atmospheric environmental hazards at local, regional,
and global scales.

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