SLCP Research Digest
(January & February 2014)
The SLCP Research Digest is a bi-monthly publication aimed at compiling the top research in fields related to short-lived
climate pollutants. While the Digest draws from a wide list of scientific research publications it is not meant to be a fully
exhaustive compilation of the relevant published research. Suggestions for published research to be included in future
Digests should be emailed to ccac_secretariat@unep.org, with the subject line 'For SLCP Research Digest' we particularly
welcome published research from non-English sources.
Note - To jump directly to a particular article or section, go to the Table of Contents and simply hold ctrl and left click on
the title of the article or section you wish to read.
Table of Contents
Short-Lived Climate Pollutants.............................................................................................................................. 4
What Role for Short-Lived Climate Pollutants in Mitigation Policy? ........................................................................................... 4
Short-Lived Climate Pollution (CO2-DOMINANT PERSPECTIVE) ................................................................................................ 4
Bottom-Up Solutions to Mitigating Climate Change ...................................................................................................................... 4
Methane ................................................................................................................................................................. 4
Methane Leaks from North American Natural Gas Systems ........................................................................................................ 4
Economic Analysis of Methane Emission Reduction Opportunities in the U.S. Onshore Oil and Natural Gas
Industries ................................................................................................................................................................................................ 5
Black Carbon ......................................................................................................................................................... 5
Estimating Black Carbon Emissions from Agricultural Burning .................................................................................................. 5
Double blanket effect caused by two layers of black carbon aerosols escalates warming in the Brahmaputra River
Valley ....................................................................................................................................................................................................... 6
Global budget and radiative forcing of black carbon aerosol: Constraints from pole-to-pole (HIPPO) observations
across the Pacific ................................................................................................................................................................................... 6
PM2.5: global progress in controlling the motor vehicle contribution .......................................................................................... 6
Analysis of transpacific transport of black carbon during HIPPO-3: implications for black carbon aging
(DISCUSSION DRAFT)..................................................................................................................................................................... 7
Two hundred fifty years of aerosols and climate: the end of the age of aerosols ....................................................................... 7
Anthropogenic and natural causes of climate change ..................................................................................................................... 7
Black carbon emissions from in-use ships: a California regional assessment .............................................................................. 7
Emissions from the Brick Manufacturing Industry (Book Chapter) ............................................................................................ 8
Remote influence of South Asian black carbon aerosol on East Asian summer climate .......................................................... 8
Characteristics and relevant remote sources of black carbon aerosol in Shanghai..................................................................... 9
Long term trends in Black Carbon Concentrations in the Northeastern United States ............................................................ 9
Case study of absorption aerosol optical depth closure of black carbon over the East China Sea ......................................... 9
The effect of aerosols on long wave radiation and global warming.............................................................................................. 9
Hydrofluorocarbons .............................................................................................................................................. 10
Growth of climate change commitments from HFC banks and emissions (DISCUSSION DRAFT) ................................ 10
Tropospheric Ozone ............................................................................................................................................. 10
Comparison of ozone pollution levels at various sites in Seoul, a megacity in Northeast Asia ............................................. 10
Air Pollution and Health ....................................................................................................................................... 11
China’s international trade and air pollution in the United States............................................................................................... 11
Cardiovascular Disease Risk Profiling in Africa: Environmental Pollutants are not on the Agenda .................................... 11
Exposure to ambient black carbon derived from a unique inventory and high-resolution model ........................................ 11
Household Air Pollution from Cookstoves: Impacts on Health and Climate (Book Chapter) ............................................. 12
The Human Health Co-benefits of Air Quality Improvements Associated with Climate Change Mitigation (Book
Chapter) ................................................................................................................................................................................................ 12
The Effects of Climate Change and Air Pollution on Children and Mothers’ Health (Book Chapter)................................ 12
Air Quality Modeling in East Asia: present issues and future directions ................................................................................... 12
Effects of fine particulate matter and its constituents on low birth weight among full-term infants in California ............ 13
Prenatal air pollution exposure and ultrasound measures of fetal growth in Los Angeles, California.................................. 13
Associations of PM2.5 Constituents and Sources with Hospital Admissions: Analysis of Four Counties in
Connecticut and Massachusetts (USA) for Persons ≥65 Years of Age ..................................................................................... 13
Exposure-Response Estimates for Diesel Engine Exhaust and Lung Cancer Mortality Based on Data from Three
Occupational Cohorts ........................................................................................................................................................................ 14
Addressing the Burden of Disease Attributable to Air Pollution in India: The Need to Integrate across Household
and Ambient Air Pollution Exposures ............................................................................................................................................ 14
Agriculture ............................................................................................................................................................ 14
Reducing greenhouse gas emissions and adapting agricultural management for climate change in developing
countries: providing the basis for action ......................................................................................................................................... 14
Optimizing rice yields while minimizing yield-scaled global warming potential ....................................................................... 15
Ruminants, climate change and climate policy ............................................................................................................................... 15
Biomass Burning & Cooking and Heating .......................................................................................................... 15
Impacts of controlling biomass burning emissions on wintertime carbonaceous aerosol in Europe ................................... 15
Enablers and Barriers to Large-Scale Uptake of Improved Solid Fuel Stoves: A Systematic Review................................... 16
Regional Impacts .................................................................................................................................................. 16
Observational determination of albedo decrease caused by vanishing Arctic sea ice .............................................................. 16
Click Here to Return to the Table of Contents
SHORT-LIVED CLIMATE POLLUTANTS
What Role for Short-Lived Climate Pollutants in Mitigation Policy?
Summary - Short-lived climate pollutants (SLCPs) include methane (CH4), black carbon (BC), tropospheric ozone, and
hydro- fluorocarbons (HFCs). They are important contributors to anthropogenic climate change, responsible for as much as
one-third of the current total greenhouse forcing (1). An emerging strategy, which we refer to as hybrid climate mitigation
(HCM), emphasizes reducing SLCPs in parallel with long- lived carbon dioxide (CO2) so as to achieve climate goals, as well
as health and food security benefits, associated with some of the SLCPs. Proponents of HCM argue that we should focus
substantial effort on reducing SLCPs now, as we wait for sufficient political will to reduce CO2 emissions (2– 4). But others
(5) worry that any strategy involving SLCPs risks delaying efforts to reduce CO2, the main greenhouse gas most important
for long-term warming if emissions continue as projected.
Shoemaker, J.K., D.P. Schrag, M.J. Molina, V. Ramanathan (2013) What Role for Short-Lived Climate Pollutants in Mitigation
Policy?, SCIENCE 342:1323-1324.
Short-Lived Climate Pollution
Abstract - Although carbon dioxide emissions are by far the most important mediator of anthropogenic climate disruption,
a number of shorter-lived substances with atmospheric lifetimes of under a few decades also contribute significantly to the
radiative forcing that drives climate change. In recent years, the argument that early and aggressive mitigation of the emission
of these substances or their precursors forms an essential part of any climate protection strategy has gained a considerable
following. There is often an implication that such control can in some way make up for the current inaction on carbon
dioxide emissions. The prime targets for mitigation, known collectively as short-lived climate pollution (SLCP), are methane,
hydrofluorocarbons, black carbon, and ozone. A re-examination of the issues shows that the benefits of early SLCP
mitigation have been greatly exaggerated, largely because of inadequacies in the methodologies used to compare the climate
effects of short-lived substances with those of CO2, which causes nearly irreversible climate change persisting millennia after
emissions cease. Eventual mitigation of SLCP can make a useful contribution to climate protection, but there is little to be
gained by implementing SLCP mitigation before stringent carbon dioxide controls are in place and have caused annual
emissions to approach zero. Any earlier implementation of SLCP mitigation that substitutes to any significant extent for
carbon dioxide mitigation will lead to a climate irreversibly warmer than will a strategy with delayed SLCP mitigation. SLCP
mitigation does not buy time for implementation of stringent controls on CO2 emissions.
Pierrehumbert, R.T. (2014) Short-Lived Climate Pollution, ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES 42.
Bottom-Up Solutions to Mitigating Climate Change
Summary - Significant attention has been focused on fashioning multilateral agreements to slow CO2 emissions from fossil
fuels. These efforts are essential for reducing long-term warming, but more can be done to slow near-term warming
significantly by enlisting social entrepreneurs, NGOs, impact investors, and philanthropists in creating bottom-up solutions
to climate change mitigation.
Seddon, J. & Veerabhadran Ramanathan (2013) Bottom-Up Solutions to Mitigating Climate Change, STANFORD SOCIAL
INNOVATION REVIEW.
Click Here to Return to the Table of Contents
METHANE
Methane Leaks from North American Natural Gas Systems
Summary - This study presents a first effort to systematically compare published CH4 emissions estimates at scales ranging
from device- level (>103 g/year) to continental-scale atmospheric studies (>1013 g/year). Studies known to us that (i) report
measurement- based emissions estimates and (ii) compare those estimates with inventories or established emission factors
(EFs) are shown in the first chart.
We include in the second chart a range of excess CH4 from all sources (7 to 21 × 1012 g or Tg/year) based on normalized
national-scale atmospheric studies from the inset in the first chart. This excess is conservatively defined as 1.25 to 1.75 times
EPA GHGI estimates. This estimate is derived from national-scale atmospheric studies and includes all sources of CH4
emissions: It should not be expected that NG sources are responsible for all excess CH4.
The scenarios in the second chart for NG production and/or processing, distribution, and petroleum system emissions apply
observed leakage rates from the literature that are higher than EPA GHGI estimates. The frequency of such high-emitting
practices is unknown, so illustrative prevalence scenarios are plotted: 1, 10, or 25% of activity is represented by high-emitters;
the remaining facilities emit at EPA GHGI rates. This evidence suggests that high leak- age rates found in recent studies are
unlikely to be representative of the entire NG industry; if this were the case, associated emissions would exceed observed
total excess atmospheric CH4 from all sources.
In general, the wide ranges in the second chart suggest a poor understanding of sources of excess CH4 and point to areas
where improved science would reduce uncertainty. However, hydraulic fracturing for NG is unlikely to be a dominant
contributor to total emissions. Also, some sources not included in the GHGI may con- tribute to measured excess CH4, e.g.,
abandoned oil and gas wells and geologic seeps (see SM).
Brandt, A. R., G. A. Heath, E. A. Kort, F. O’Sullivan, G. Pétron, S. M. Jordaan, P. Tans, J. Wilcox, A. M. Gopstein, D.
Arent, Wofsy, N. J. Brown, R. Bradley, G. D. Stucky, D. Eardley, R. Harriss (2014) Methane Leaks from North American Natural
Gas Systems, SCIENCE 343:733-735.
Economic Analysis of Methane Emission Reduction Opportunities in the U.S. Onshore Oil and Natural
Gas Industries
Executive Summary – Methane is an important climate change forcing greenhouse gas (GHG) with a short‐term impact
many times greater than carbon dioxide. Methane comprised 9% of U.S. greenhouse gas (GHG) emissions in 2011
according to the U.S. EPA Inventory of US Greenhouse Gas Emission and Sinks: 1990‐2011, and would comprise a
substantially higher portion based on a shorter timescale measurement. Recent research also suggests that mitigation of
short‐term climate forcers such as methane is a critical component of a comprehensive response to climate change.
Emissions from the oil and gas industry are among the largest anthropogenic sources of U.S. methane emissions. At the
same time, there are many ways to reduce emissions of fugitive and vented methane from the oil and gas industry and,
because of the value of the gas that is conserved, some of these measures actually save money or have limited net cost.
Abatement Opportunities – By volume, the largest opportunities target leak detection and repair of fugitive emissions
(“leaks”) at facilities and gas compressors, reduced venting of associated gas, and replacement of high‐emitting pneumatic
devices.
Co‐Benefits – Reducing methane emissions will also reduce ‐ at no extra cost‐conventional pollutants that can harm public
health and the environment. The methane reductions projected here would also result in a 44% reduction in volatile organic
compounds (VOCs) and hazardous air pollutants (HAPs) associated with methane emissions from the oil and gas industry.
ICF International, ECONOMIC ANALYSIS OF METHANE EMISSION REDUCTION OPPORTUNITIES IN THE U.S. ONSHORE
OIL AND NATURAL GAS INDUSTRIES, prepared for Environmental Defense Fund (2014).
Click Here to Return to the Table of Contents
BLACK CARBON
Estimating Black Carbon Emissions from Agricultural Burning
Abstract - High sensitivity of the Arctic region to short-lived climate forcers, including black carbon (BC), makes crop
residue burning an important source of emissions. A high to moderate uncertainty in cropland burning emission estimates
from remote sensing-based analyses currently exists and is problematic for establishing baseline estimates of black carbon
emissions from global remote sensing products. Straw burning and possible BC emissions were estimated at the oblast level
for Russia for years 2003 through 2010. A study was based on 1 km Moderate Resolution Spectroradiometer (MODIS)
Active Fire Product, oblast level agricultural statistics, 1:25,000–1:50,000 scale GIS vector field maps and developing
algorithms for calculating the size and intensity of fires as well as testing the accuracy of the predictions in areas with contrast
land use. Both Active Fire Product and statistics methods demonstrated consistent results, including increasing fire activity in
the years with additional straw surplus and the highest absolute values for vast territories with quite intensive grain
production, mainly in European Russia. Straw burning can be a source of at least 1/3 total BC emissions from agriculture
and grassland fires and does not appear to be the main source of total BC emissions for the Russian Federation. For regions
with small number of cropland fires, the accuracy of existing remote sensing-based land cover products is insufficient for
reliable classification of agricultural fires from satellite products. Incorrect classification of agricultural fires may exceed 25%,
increasing for the northern part of the country where forests are the predominant land cover. An improved method would
be to calculate BC emissions from burned area using high resolution field masks and ground validation of fire sources in
cropland areas.
Romanenkov, V., D. Rukhovich, P. Koroleva, & J. L. McCarty (2014) Estimating Black Carbon Emissions from Agricultural
Burning, ENVIRONMENTAL SCIENCE AND ENGINEERING 347-364.
Double blanket effect caused by two layers of black carbon aerosols escalates warming in the
Brahmaputra River Valley
Abstract - First ever 3-day aircraft observations of vertical profiles of Black Carbon (BC) were obtained during the Cloud
Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted on 30th August, 4th and 6th
September 2009 over Guwahati (26°11′N, 91°44′E), the largest metropolitan city in the Brahmaputra River Valley (BRV)
region. The results revealed that apart from the surface/near surface loading of BC due to anthropogenic processes causing a
heating of 2K/day, the large-scale Walker and Hadley atmospheric circulations associated with the Indian summer monsoon
help in the formation of a second layer of black carbon in the upper atmosphere, which generates an upper atmospheric
heating of ~2 K/day. Lofting of BC aerosols by these large-scale circulating atmospheric cells to the upper atmosphere (4–6
Km) could also be the reason for extreme climate change scenarios that are being witnessed in the BRV region.
Rahul, P.R.C., R.L. Bhawar, D.C. Ayantika, A.S. Panicker, P.D. Safai, V. Tharaprabhakaran, B. Padmakumari, & M.P. Raju
(2014) Double blanket effect caused by two layers of black carbon aerosols escalates warming in the Brahmaputra River Valley, NATURE SCIENTIFIC
REPORTS.
Global budget and radiative forcing of black carbon aerosol: Constraints from pole-to-pole (HIPPO)
observations across the Pacific
Abstract - We use a global chemical transport model (GEOS-Chem) to interpret aircraft curtain observations of black
carbon (BC) aerosol over the Pacific from 85°N to 67°S during the 2009–2011 HIAPER (High-Performance Instrumented
Airborne Platform for Environmental Research) Pole-to-Pole Observations (HIPPO) campaigns. Observed concentrations
are very low, implying much more efficient scavenging than is usually implemented in models. Our simulation with a global
source of 6.5 Tg a−1 and mean tropospheric lifetime of 4.2 days (versus 6.8 ± 1.8 days for the Aerosol Comparisons between
Observations and Models (AeroCom) models) successfully simulates BC concentrations in source regions and continental
outflow and captures the principal features of the HIPPO data but is still higher by a factor of 2 (1.48 for column loads) over
the Pacific. It underestimates BC absorbing aerosol optical depths (AAODs) from the Aerosol Robotic Network by 32% on
a global basis. Only 8.7% of global BC loading in GEOS-Chem is above 5 km, versus 21 ± 11% for the AeroCom models,
with important implications for radiative forcing estimates. Our simulation yields a global BC burden of 77 Gg, a global
mean BC AAOD of 0.0017, and a top-of-atmosphere direct radiative forcing (TOA DRF) of 0.19 W m−2, with a range of
0.17–0.31 W m−2 based on uncertainties in the BC atmospheric distribution. Our TOA DRF is lower than previous estimates
(0.27 ± 0.06 W m−2 in AeroCom, 0.65–0.9 W m−2 in more recent studies). We argue that these previous estimates are biased
high because of excessive BC concentrations over the oceans and in the free troposphere.
Qiaogiao, Q. W., D. J. Jacob, J. R. Spackman, A. E. Perring, J. P. Schwarz, N. Moteki, E. A. Marais, C. Ge, J. Wang, & S. R.
H. Barrett (2014) Global budget and radiative forcing of black carbon aerosol: Constraints from pole-to-pole (HIPPO) observations across the
Pacific, JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES.
PM2.5: global progress in controlling the motor vehicle contribution
Abstract - It is well established that ambient particles in the size range of 2.5 microns or less case a wide variety of adverse
health effects. According to a recent study from the World Health Organization, in 2010 these effects resulted in
approximately 3.2 million premature deaths with vehicles being one of the significant contributors. Diesel vehicle particulate
emissions which are virtually all smaller than 2.5 microns raise additional special concerns due to their carcinogenicity and
high ratio of black carbon (BC) to organic carbon; black carbon has recently been found to be the second most important
contributor to climate change after carbon dioxide. Other pollutants emitted by diesels and other vehicles such as the oxides
of nitrogen and volatile organic compounds also contribute to ambient particulate matter smaller than 2.5 microns in size
(PM2.5) after undergoing secondary transformations in the atmosphere. Technologies have been developed that can
dramatically reduce vehicle emissions when clean, low sulfur fuels are available and these technologies are being phased in
throughout the industrialized world resulting in a global decrease in particulate matter (PM) and BC emissions from vehicles.
However the vehicle population is growing rapidly in the developing world, leading to increases in emissions in many
countries. Unless these rapidly industrializing countries move to state of the art vehicles and clean fuels, global PM, BC and
NO x emissions from road vehicles will start to turn up over the next 10 to 15 years.
Walsh, M. P. (2014) PM2.5: global progress in controlling the motor vehicle contribution, FRONTIERS OF ENVIRONMENTAL
SCIENCE & ENGINEERING 8(1):1-17.
Analysis of transpacific transport of black carbon during HIPPO-3: implications for black carbon aging
Abstract - Long-range transport of black carbon (BC) is a growing concern as a result of the efficiency of BC in warming
the climate and its adverse impact on human health. We study transpacific transport of BC during HIPPO-3 using a
combination of inverse modeling and sensitivity analysis. We use the GEOS-Chem chemical transport model and its adjoint
to constrain Asian BC emissions and estimate the source of BC over the North Pacific. We find that different sources of BC
dominate the transport to the North Pacific during the southbound (29 March 2010) and northbound (13 April 2010)
measurements in HIPPO-3. While biomass burning in Southeast Asia (SE) contributes about 60% of BC in March, more
than 90% of BC comes from fossil fuel and biofuel combustion in East Asia (EA) during the April mission. GEOS-Chem
simulations generally resolve the spatial and temporal variation of BC concentrations over the North Pacific, but are unable
to reproduce the low and high tails of the observed BC distribution. We find that the optimized BC emissions derived from
inverse modeling fail to improve model simulations significantly. This failure indicates that uncertainties in BC transport,
rather than in emissions, account for the major biases in GEOS-Chem simulations of BC.
The aging process, transforming BC from hydrophobic into hydrophilic form, is one of the key factors controlling wet
scavenging and remote concentrations of BC. Sensitivity tests on BC aging suggest that the aging time scale of anthropogenic
BC from EA is several hours, faster than assumed in most global models, while the aging process of biomass burning BC
from SE may occur much slower, with a time scale of a few days. To evaluate the effects of BC aging and wet deposition on
transpacific transport of BC, we develop an idealized model of BC transport. We find that the mid-latitude air masses
sampled during HIPPO-3 may have experienced a series of precipitation events, particularly near the EA and SE source
region. Transpacific transport of BC is sensitive to BC aging when the aging rate is fast; this sensitivity peaks when the aging
time scale is in the range of 1–1.5 d. Our findings indicate that BC aging close to the source must be simulated accurately at a
process level in order to simulate better the global abundance and climate forcing of BC.
Shen, Z., J. Liu, L.W. Horowitz, D.K. Henze, S. Fan, H. Levy II, D.L. Mauzerall, J.-T. Lin, & S. Tao (2014) Analysis of
transpacific transport of black carbon during HIPPO-3: implications for black carbon aging, ATMOSPHERIC CHEMISTRY AND PHYSICS
(DISCUSSION DRAFT).
Two hundred fifty years of aerosols and climate: the end of the age of aerosols
Abstract - Carbonaceous and sulfur aerosols have a substantial global and regional influence on climate, resulting in a net
cooling to date, in addition to their impact on health and ecosystems. The magnitude of this influence has changed
substantially over the past and is expected to continue to change into the future. An integrated picture of the changing
climatic influence of black carbon, organic carbon and sulfate over the period 1850 through 2100, focusing on uncertainty, is
presented using updated historical inventories and a coordinated set of emission projections. We describe, in detail, the
aerosol emissions from the RCP4.5 scenario and its associated reference scenario. While aerosols have had a substantial
impact on climate over the past century, we show that, by the end of the 21st century, aerosols will likely be only a minor
contributor to radiative forcing due to increases in greenhouse gas forcing and a net global decrease in pollutant emissions.
This outcome is even more certain under a successful implementation of a policy to limit greenhouse gas emissions as lowcarbon energy technologies that do not emit appreciable aerosol or SO2 are deployed.
Smith, S.J., T.C. Bond (2014) Two hundred fifty years of aerosols and climate: the end of the age of aerosols, ATMOSPHERIC CHEMISTRY
AND PHYSICS 14:537-549.
Anthropogenic and natural causes of climate change
Abstract - We test for causality between radiative forcing and temperature using multivariate time series models and
Granger causality tests that are robust to the non-stationary (trending) nature of global climate data. We find that both
natural and anthropogenic forcings cause temperature change and also that temperature causes greenhouse gas concentration
changes. Although the effects of greenhouse gases and volcanic forcing are robust across model specifications, we cannot
detect any effect of black carbon on temperature, the effect of changes in solar irradiance is weak, and the effect of
anthropogenic sulfate aerosols may be only around half that usually attributed to them.
Stern, D. I., & R. K. Kaufmann (2014) Anthropogenic and natural causes of climate change, CLIMATIC CHANGE 122(1-2):257-269..
Black carbon emissions from in-use ships: a California regional assessment
Abstract - Black carbon (BC) mass emission factors (EFBC; gBC (kgfuel)−1) from a variety of ocean-going vessels have
been determined from measurements of BC and carbon diox- ide (CO2) concentrations in ship plumes intercepted by the
R/V Atlantis during the 2010 California Nexus (CalNex) campaign. The ships encountered were all operating within 24
nautical miles of the California coast and were utilizing relatively low sulphur fuels (average fuel sulphur content of 0.4%,
0.09% and 0.03% for vessels operating slow-speed, medium-speed and high-speed diesel engines, respectively). Black carbon
concentrations within the plumes, from which EFBC values are determined, were measured using four in- dependent
instruments: a photoacoustic spectrometer and a particle soot absorption photometer, which measure light ab- sorption, and
a single particle soot photometer and soot particle aerosol mass spectrometer, which measure the mass con- centration of
refractory BC directly. These measurements have been used to assess the level of agreement between these different
techniques for the determination of BC emission factors from ship plumes. Also, these measurements greatly expand upon
the number of individual ships for which BC emission factors have been determined during real-world operation. The
measured EFBC’s have been divided into vessel type categories and engine type categories, from which averages have been
determined. The geometric average EFBC (excluding outliers) determined from over 71 vessels and 135 plumes encountered
was 0.31±0.31gBC(kgfuel)−1, where the standard deviation represents the variability between individual vessels. The most
frequent engine type encountered was the slow-speed diesel (SSD), and the most frequent SSD vessel type was the cargo
ship sub-category. Average and median EFBC values from the SSD category are compared with previous observations from
the Texas Air Quality Study (TexAQS) in 2006, during which the ships encountered were predominately operating on highsulphur fuels (average fuel sulphur content of 1.6%). There is a statistically significant difference between the EFBC values
from CalNex and Tex- AQS for SSD vessels and for the cargo and tanker ship types within this engine category. The CalNex
EFBC values are lower than those from TexAQS, suggesting that operation on lower sulphur fuels is associated with smaller
EFBC values.
Buffaloe, G. M., D. A. Lack, E. J. Williams, D. Coffman, K. L. Hayden, B. M. Lerner, S.-M. Li, I. Nuaaman, P. Massoli, T. B.
Onasch, P. K. Quinn, & C. D. Cappa (2014) Black carbon emissions from in-use ships: a California regional assessment, ATMOS.
CHEM. PHYS. 14:1881-1896.
Emissions from the Brick Manufacturing Industry (Book Chapter)
Abstract - Brick manufacturing is the fastest-growing industrial sector in Bangladesh and among the major contributors to
the air pollution and health problems in Dhaka, along with vehicle exhaust, resuspended road dust, and domestic fuel
burning. There are about 1,000 brick kilns in Dhaka region from the districts of Dhaka, Gazipur, Manikganj, and
Narayanganj. Brick manufacturing is confined to the non-monsoonal months and produces 3.5 billion bricks per year, using
energy-inefficient fixed-chimney Bull trench kiln technology fuelled with coal and agricultural waste. The total annual
emissions are estimated as 23,300 tons of PM2.5, 15,500 tons of SO2, 302,000 tons of CO, 6,000 tons of black carbon, and 1.8
million tons of CO2. The associated health impacts largely fall on the densely populated districts of Dhaka, Gazipur, and
Narayanganj. Using the ATMoS dispersion model, the impact of brick kiln emissions was estimated over Dhaka region –
ranging from 7 to 99 μg/m3 (5th and 95th percentile concentration per model grid) at an average of 38 μg/m3 – and
provincial cluster contributions of 27 % originating from Narayanganj (to the south with the highest kiln density), 30 % from
Gazipur (to the north with equally large cluster spread along the river and canals), and 23% from Savar of Dhaka district.
The modelling results were validated using evidence from receptor modelling studies conducted in Dhaka region. An
introduction of emerging vertical shaft combustion technology and a possible relocation of the northern clusters to the
southeast can provide faster benefits for public health and reduce climate precursor emissions.
Guttikunda, S. K. (2014) Emissions from the Brick Manufacturing Industry, in DHAKA MEGACITY: GEOSPATIAL PERSPECTIVES
ON URBANISATION, ENVIRONMENT AND HEALTH SERIES, Springer Geography (Ashraf Dewan & Robert Corner eds.).
Remote influence of South Asian black carbon aerosol on East Asian summer climate
Abstract - The remote impact of South Asian black carbon (SABC) aerosol on East Asian summer monsoon (EASM) was
studied and compared with the local impact of local East Asian black carbon (EABC) by using ensemble sensitive
experiments in atmospheric general circulation model, GFDL AM2.1. The results show that SABC causes a south–north
tripolar precipitation response pattern over East Asia. This includes reduced rainfall over a central area from the Yangtze
River valley to East China Sea and southern Japan but intensified rainfall over a northern domain ranging from northern
China/Korea to northern Japan as well as over a southern domain, southern China. Such SABC induced changes are about
5–10% of the observed climatological rainfalls in East Asia. Mechanistically, such a remote effect is realized through a
propagating wave train along the Asian upper tropospheric jet. The wave train disperses South Asian atmospheric signals
downstream and causes intensification of the western Pacific subtropical anticyclone (WPSA), resulting in weakened
moisture supply toward East Asia from the Bay of Bengal. In addition, the remote circulation response enhances
atmospheric stability over the Yangtze River valley. These two effects together cause rainfall reduction in the Yangtze River
valley. Besides, the remote effect tends to offset a fraction of rainfall intensification induced by local EABC. Copyright ©
2013 Royal Meteorological Society
Mahmood, R., & S. Li (2014) Remote influence of South Asian black carbon aerosol on East Asian summer climate, INTERNATIONAL
JOURNAL OF CLIMATOLOGY 34(1):36-48.
Characteristics and relevant remote sources of black carbon aerosol in Shanghai
Abstract - Black carbon (BC) aerosol was measured continuously at an urban site in Shanghai (31°18′N, 121°30′E) from
January 2011 to January 2012, and the characteristics and relevant remote sources of BC were examined. Daily BC
concentrations varied within the range of 0.3–11.4 μg m−3 with an annual average of 2.3 μg m−3. Comparably, monthly BC
concentrations were usually high in the dry season (November–April) but low in the wet season (May–October). Hourly BC
showed a similar diurnal pattern with two peaks, one at 7:00–9:00 LT and another at 19:00–21:00 LT, in the four seasons.
BC level was always relatively higher during daytime than nighttime. There also existed a workday/weekend difference of BC
due to anthropogenic activities. The correlation analyses between BC and meteorological factors indicated that (1) wind
speed was an important contributor to BC diffusion in the boundary atmosphere, (2) atmospheric visibility was not highly
sensitive to BC, and (3) northwesterly, westerly and southwesterly wind directions related closely to BC. The increase of BC
is likely associated with fossil fuel combustion during the winter heating period and agricultural waste burning over the
surrounding areas during the summer harvest period, as well as the air masses originating from and/or transiting through
these regions.
Zhaa, S., T. Chenga, J. Tao, R. Zhange, J. Chena, Y. Zhang, C. Leng, D. Zhang, & J. Du (2014) Characteristics and relevant
remote sources of black carbon aerosol in Shanghai, ATMOSPHERIC RESEARCH 135-136:159-171.
Long term trends in Black Carbon Concentrations in the Northeastern United States
Abstract - We report BC concentrations, ([BC]), measured using the thermal optical method, in monthly composites of daily
particulate samples collected at rural Mayville, NY from 1984 to 2010. The monthly concentrations ranged from 10 to 900
ng m−3, and showed decreasing trend with a slope of −5.5 ng m−3 per year, and a 32% decrease over the 27-year period. The
monthly [BC] varied weakly with season but generally peaked in late summer. An aethalometer was also used to measure
[BC], in real time, every 5 min from May 2008 to December, 2010. Measurements were made at 370 and 880 nm wavelengths. Although both channels are calibrated as BC, fresh wood combustion emissions include polycyclic aromatic
hydrocarbons that enhance the 370 nm channel signal. We utilize this to estimate that the wood burning contributed 18% of
the BC on an annual basis, but accounted for ~30% in winter and ~8% during summer. BC concentration from local and
transported sources was calculated based on aethalometer BC and HYSPLIT 4 air trajectories. The highest [BC] were
associated with air masses that passed through the Ohio River Valley as well as through the Mid-Atlantic States. However,
when integrated over time 68% of the BC transported to the site arrived from OH, KY, IN, IL, MI, WI, and southern
Ontario.
Ahmed, T., V. A. Dutkiewicz, A.J. Khana, & L. Husain (2014) Long term trends in Black Carbon Concentrations in the Northeastern
United States, ATMOSPHERIC RESEARCH 137:49-57.
Case study of absorption aerosol optical depth closure of black carbon over the East China Sea
Abstract - Absorption aerosol optical depth (AAOD) measurements made by sun-sky photometers are currently the only
constraint available for estimates of the global radiative forcing of black carbon (BC), but their validation studies are limited.
In this paper, we report the first attempt to compare AAODs derived from single-particle soot photometer (SP2) and
ground-based sun-sky photometer (sky radiometer, SKYNET) measurements. During the Aerosol Radiative Forcing in East
Asia (A-FORCE) experiments, BC size distribution and mixing state vertical profiles were measured using an SP2 on board a
research aircraft near the Fukue Observatory (32.8°N, 128.7°E) over the East China Sea in spring 2009 and late winter 2013.
The aerosol extinction coefficients (bext) and single scattering albedo (SSA) at 500 nm were calculated based on aerosol size
distribution and detailed BC mixing state information. The calculated aerosol optical depth (AOD) agreed well with the sky
radiometer measurements (2 ± 6%) when dust loadings were low (lidar-derived nonspherical particle contribution to AOD
less than 20%). However, under these low-dust conditions, the AAODs obtained from sky radiometer measurements were
only half of the in situ estimates. When dust loadings were high, the sky radiometer measurements showed systematically
higher AAODs even when all coarse particles were assumed to be dust for in situ measurements. These results indicate that
there are considerable uncertainties in AAOD measurements. Uncertainties in the BC refractive index, optical calculations
from in situ data, and sky radiometer retrieval analyses are discussed.
Koike, M., N. Moteki, P. Khatri, T. Takamura, N. Takegawa, Y. Kondo, H. Hashioka, H. Matsui, A. Shimizu, & N.
Sugimoto (2014) Case study of absorption aerosol optical depth closure of black carbon over the East China Sea, JOURNAL OF
GEOPHYSICAL RESEARCH: ATMOSPHERES 119(1):122-136.
The effect of aerosols on long wave radiation and global warming
Abstract - The effect of aerosols on long wave (LW) radiation was studied based on narrowband LW calculations in a
reference mid-latitude summer atmosphere with and without aerosols. Aerosols were added to the narrowband LW scheme
based on their typical schematic observed spectral and vertical behaviour over European land areas. This was found to agree
also with the spectral aerosol data from the Lan Zhou University Semi-Arid Climate Observatory and Laboratory
measurement stations in the north-western China.
A volcanic stratospheric aerosol load was found to induce local LW warming and a stronger column “greenhouse effect”
than a doubled CO2 concentration. A heavy near-surface aerosol load was found to increase the downwelling LW radiation
to the surface and to reduce the outgoing LW radiation, acting very much like a thin low cloud in increasing the LW
greenhouse effect of the atmosphere. The short wave reflection of white aerosol has, however, stronger impact in general,
but the aerosol LW greenhouse effect is non-negligible under heavy aerosol loads.
Zhou, Y. & H. Savijärvi (2014) The effect of aerosols on long wave radiation and global warming, ATMOSPHERIC RESEARCH 135136:102-111.
Click Here to Return to the Table of Contents
HYDROFLUOROCARBONS
Growth of climate change commitments from HFC banks and emissions
Abstract - Chlorofluorocarbons (CFCs) are the primary cause of ozone depletion, and they also contribute to global climate
change. With the global phaseout of CFCs and the coming phaseout of hydrochlorofluorocarbons (HCFCs), the substitute
hydrofluorocarbons (HFCs) are increasingly used. While CFCs were originally used mainly in applications5 such as spray
cans and were released within a year after production, concern about the ozone layer led to reductions in rapid-release
applications, and the relative importance of slower-release applications grew. HFCs are now mainly used in refrigerators and
air-conditioners (AC) and are released over years to a decade after production. Their containment in such equipment
represents banks, which are building up as production grows. A key finding of our work is that the increases of HFC banks
represent a substantial unseen commitment to further radiative forcing of climate change after production of the chemicals
ceases. We show that earlier phaseouts of HFCs would provide greater benefits for climate protection than previously
recognized, due to the avoided buildup of the banks. If, for example, HFC production were to be phased out in 2020 instead
of 2050, not only would about 91–146GtCO2eq of cumulative emis- sion be avoided from 2020 to 2050, but an additional
bank of about 39–64GtCO2eq is also avoided in 2050. Choices of later phaseout dates lead to larger commitments to climate
change unless growing banks of HFCs from millions of dispersed locations are collected and destroyed.
Velders, G.J.M., S. Solomon, & J.S. Daniel (2013) Growth of climate change commitments from HFC banks and emissions,
Atmospheric Chemistry and Physics 13:32989-33012.
Click Here to Return to the Table of Contents
TROPOSPHERIC OZONE
Comparison of ozone pollution levels at various sites in Seoul, a megacity in Northeast Asia
Abstract - Concentrations of ozone were continuously measured at four urban monitoring sites (Gu Ro (G); No Won (N);
Song Pa (S); and Yong San (Y)) in Seoul, Korea from 2009 to 2011. The annual mean concentrations of ozone (in ppb) at
these sites were found on the order of N (21.8 ± 19.3) > S (21.4 ± 20.14) > G (20.9 ± 18.0) > Y (18.8 ± 17.4). During
peak hours (12–6 pm), the ozone concentrations were significantly higher (75, 69, 67, and 64% at site S, Y, N, and G,
respectively) than overall 24 hour mean values. Seasonal variations of ozone have quite similar patterns at every site with
systematic increases during spring (March–May) and summer (June–August) with the summer daytime mean (12–6 pm)
values of 40.7 (site Y)–49.3 ppb (site S). The concentrations of ozone exhibited strong inverse correlations with other criteria
pollutants (e.g., oxides of nitrogen and carbon monoxide), while a significant positive correlation was observed with some
meteorological parameters (e.g., ultraviolet ray and solar radiation). Evidence collected in this study confirm that the spatiotemporal distribution of ozone in the study areas should be affected by the anthropogenic sources (e.g., vehicles, residential,
and industrial sources) in concert with such well-known variables as the NOx–VOC chemistry and a number of natural
parameters (e.g., wind speed, geographic position, and solar radiation).
Iqbal, M. A., K. K. Z. Shon, J. Sohn, E. Jeon, Y. Kim, & J. Oh (2014) Comparison of ozone pollution levels at various sites in Seoul, a
megacity in Northeast Asia, ATMOSPHERIC RESEARCH 138:330-345.
Click Here to Return to the Table of Contents
AIR POLLUTION AND HEALTH
China’s international trade and air pollution in the United States
Abstract - China is the world’s largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution
are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese
emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air
pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric
chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of
carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each
of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric
modeling shows that transport of the export-related Chinese pollution contributed 3–10% of annual mean surface sulfate
concentrations and 0.5–1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one
extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the
eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12–24% of sulfate
concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in
2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect
between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international
efforts to reduce transboundary air pollution.
Lin, J., D. Pan, S. J. Davis, Q. Zhang, K. He, C. Wang, D. G. Streets, D. J. Wuebbles, & D. Guan (2014) China’s international
trade and air pollution in the United States, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATED OF
AMERICA 111(5):1736-1741..
Cardiovascular Disease Risk Profiling in Africa: Environmental Pollutants are not on the Agenda
Abstract - Cardiovascular diseases (CVDs) cause significant morbidity and mortality in the world. It is known that between
1990 and 2020, the proportion of worldwide deaths from CVD will increase from 28 to 31.5% and yet the risk factors and
etiology are not completely known. WHO has declared that pollution is one of the top 10 causes of death in the world.
Environmental pollutants may therefore provide some of the missing/unknown risk factors of CVD. Studies done in USA
and Europe have demonstrated that environmental pollutants can cause induction, progression and severity of CVD and
increase the morbidity and mortality of traditional CVD risk factors. These toxicants lead to pulmonary and systemic
inflammatory responses, arterial vasoconstriction, enhanced coagulation/thrombosis, arrhythmias, atherosclerosis,
hypertension and coronary artery disease. There is now considerable evidence that Africa has a significant share of the
world’s environmental pollution, making it vulnerable to all associated CVDs. This review presents new facts and direction
for tackling CVD in Africa. African countries must now take a cue from USA to Europe and consider environmental
pollutants as one of the risk factors of CVDs.
Anakwue, R.C. & A.C. Anakwue (2014) Cardiovascular Disease Risk Profiling in Africa: Environmental Pollutants are not
on the Agenda, CARDIOVASCULAR TOXICOLOGY..
Exposure to ambient black carbon derived from a unique inventory and high-resolution model
Abstract - Black carbon (BC) is increasingly recognized as a significant air pollutant with harmful effects on human health,
either in its own right or as a carrier of other chemicals. The adverse impact is of particular concern in those developing
regions with high emissions and a growing population density. The results of recent studies indicate that BC emissions could
be underestimated by a factor of 2–3 and this is particularly true for the hot-spot Asian region. Here we present a unique
inventory at 10-km resolution based on a recently published global fuel consumption data product and updated emission
factor measurements. The unique inventory is coupled to an Asia-nested (∼50 km) atmospheric model and used to calculate
the global population exposure to BC with fully quantified uncertainty. Evaluating the modeled surface BC concentrations
against observations reveals great improvement. The bias is reduced from −88% to −35% in Asia when the unique inventory
and higher-resolution model replace a previous inventory combined with a coarse-resolution model. The bias can be further
reduced to −12% by downscaling to 10 km using emission as a proxy. Our estimated global population-weighted BC
exposure concentration constrained by observations is 2.14 μg⋅m−3; 130% higher than that obtained using less detailed
inventories and low-resolution models.
Wang, R., S. Tao, Y. Balkanski, P. Ciais, O. Boucher, J. Liu, S. Piao, H. Shen, M. R. Vuolo, M. Valari, H. Chen, Y. Chen, A.
Cozic, Y. Huang, B. Li, W. Li, G. Shen, B. Wang, & Y. Zhang (2013) Exposure to ambient black carbon delivered from a unique
inventory and high-resolution model, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATED OF
AMERICA.
Household Air Pollution from Cookstoves: Impacts on Health and Climate (Book Chapter)
Abstract - Household air pollution (HAP) is an exposure of poverty. The success in having a sustainable reduction in HAP
requires an understanding of the traditions and culture of the family as well as the causes of poverty that place the family at
the bottom of the energy ladder. An integrated approach to reducing HAP with efforts also aimed at correcting other
poverty-related issues is challenging but offers the hope for addressing root causes of poverty in a community setting that
provides a more comprehensive and sustainable approach to improving health, the environment, and, ultimately, the global
climate. From one perspective, research that provides detailed exposure-responses to HAP may seem superfluous to the
obvious need for poor families to breathe cleaner air at home. One can argue that we already have decades of information on
the health risks from outdoor air pollution or the products of incomplete combustion from tobacco smoke and so further
research is not needed. However, there is a compelling need to know how clean a stove or fuel must be to significantly
reduce health risks, so that with proper use, major implementation of such new technology may reasonably provide the
intended benefits for improved health, the regional environment, and the global climate. The alternative of providing
electrification or use of clean fuels such as LPG may not be realistic for the world’s poor for decades to come, if ever.
Addressing the key scientific gaps related to HAP and its reduction will provide critical new information that can inform
large scale implementation programs to provide sufficiently clean household air for families living in poverty, such that
diseases are prevented, a healthier lifestyle is promoted, and a reduction in global warming trends buys more time for a
planet in peril from climate change.
Martin, W. J. II, J. W. Hollingsworth, & V. Ramanathan (2014) Household Air Pollution from Cookstoves: Impacts on Health and
Climate, in GLOBAL CLIMATE CHANGE AND PUBLIC HEALTH, RESPIRATORY MEDICINE 7 (Kent E. Pinkerton, William N.
Rom eds.).
The Human Health Co-benefits of Air Quality Improvements Associated with Climate Change Mitigation
(Book Chapter)
Abstract - Fossil fuel combustion processes that generate greenhouse gases (GHG) also emit and or cause the creation of
other harmful air pollutants. Thus, while policies designed to avert the course of climate change would eventually result in
direct human health benefits from lessened global temperature changes and associated impacts, they would also bring much
more immediate ancillary human health co-benefits from the associated reduced ground-level air pollution in the short term.
Several measures aimed at reducing GHG emissions, notably the reduced use of fossil fuels such as coal, can also improve
local air quality, most notably particulate matter (PM) and ozone (O3) air pollution. Further, whereas the benefits from
climate change mitigation would materialize far in the future, these co-benefits, or ancillary benefits, would provide much
more immediate “return on investment” in climate change mitigation. Thus, as detailed below, the near-term human health
co-benefits of climate mitigation (e.g., fossil fuel emission reductions) may provide the most economically compelling
justification for immediate action towards climate change mitigation. Here we discuss the health impacts of PM and ozone,
two key air pollutants that have substantial impacts on human health and that are likely to be reduced by policies aimed at
controlling GHG emissions.
Thurston, G. D. & M. L. Bell (2014) The Human Health Co-benefits of Air Quality Improvements Associated with Climate Change
Mitigation, in GLOBAL CLIMATE CHANGE AND PUBLIC HEALTH, RESPIRATORY MEDICINE 7 (Kent E. Pinkerton, William
N. Rom eds.).
The Effects of Climate Change and Air Pollution on Children and Mothers’ Health (Book Chapter)
Abstract - Air pollution and climate change have numerous health hazards for pregnant mothers and children. Therefore,
environmental protection activities should be considered a health priority. The importance of environmental factors on
maternal and child health care should be considered one of the main public health priorities for primordial/primary
prevention of chronic diseases.
Kelishadi, R., & P. Poursafa (2014) The Effects of Climate Change and Air Pollution on Children and Mothers’ Health, in
GLOBAL CLIMATE CHANGE AND PUBLIC HEALTH, RESPIRATORY MEDICINE 7 (Kent E. Pinkerton, William N. Rom eds.).
Air Quality Modeling in East Asia: present issues and future directions
Abstract - The rapid economic growth has increased trace gas emissions in East Asia, resulting in various environmental
issues, including acid deposition, regional haze, air quality degradation, and climate change, which are critical to the human
existence. In particular, air quality degradation became an object of rising concern in East Asian countries. In order to
understand sources, transport, and chemical transformation of air pollutants, scientists have widely used atmospheric
chemical transport models (CTMs) in East Asia. Here we review our knowledge related to the present air quality issues and
their modeling, focusing on O3 and particulate matter in East Asia. We finally suggest a few recommendations for the next
generation of air quality models to improve their capability and use in this region.
Park, R. J. & S. Kim (2014) Air Quality Modeling in East Asia: present issues and future directions, Asia-Pacific JOURNAL OF
ATMOSPHERIC SCIENCES 50(1):105-120.
Effects of fine particulate matter and its constituents on low birth weight among full-term infants in
California
Abstract - Relationships between prenatal exposure to fine particles (PM2.5) and birth weight have been observed
previously. Few studies have investigated specific constituents of PM2.5, which may identify sources and major contributors
of risk. We examined the effects of trimester and full gestational prenatal exposures to PM2.5 mass and 23 PM2.5
constituents on birth weight among 646,296 term births in California between 2000 and 2006. We used linear and logistic
regression models to assess associations between exposures and birth weight and risk of low birth weight (LBW; 2500 g),
respectively. Models were adjusted for individual demographic characteristics, apparent temperature, month and year of
birth, region, and socioeconomic indicators. Higher full gestational exposures to PM2.5 mass and several PM2.5 constituents
were significantly associated with reductions in term birth weight. The largest reductions in birth weight were associated with
exposure to vanadium, sulfur, sulfate, iron, elemental carbon, titanium, manganese, bromine, ammonium, zinc, and copper.
Several of these PM2.5 constituents were associated with increased risk of term LBW. Reductions in birth weight were
generally larger among younger mothers and varied by race/ethnicity. Exposure to specific constituents of PM2.5, especially
traffic-related particles, sulfur constituents, and metals, were associated with decreased birth weight in California
Basu, R., M. Harris, L. Sie, B. Malig, R. Broadwin, & R. Green (2014) Effects of fine particulate matter and its constituents on low birth
weight among full-term infants in California, ENVIRONMENTAL RESEARCH 128:42-51.
Prenatal air pollution exposure and ultrasound measures of fetal growth in Los Angeles, California
Abstract - Background: Few previous studies examined the impact of prenatal air pollution exposures on fetal development
based on ultrasound measures during pregnancy.
Methods: In a prospective birth cohort of more than 500 women followed during 1993–1996 in Los Angeles, California, we
examined how air pollution impacts fetal growth during pregnancy. Exposure to traffic related air pollution was estimated
using CALINE4 air dispersion modeling for nitrogen oxides (NOx) and a land use regression (LUR) model for nitrogen
monoxide (NO), nitrogen dioxide (NO2) and NOx. Exposures to carbon monoxide (CO), NO2, ozone (O3) and particles 10
μm in aerodynamic diameter (PM10) were estimated using government monitoring data. We employed a linear mixed effects
model to estimate changes in fetal size at approximately 19, 29 and 37 weeks gestation based on ultrasound.
Results: Exposure to traffic-derived air pollution during 29 to 37 weeks was negatively associated with biparietal diameter at
37 weeks gestation. For each interquartile range (IQR) increase in LUR-based estimates of NO, NO2 and NOx, or freeway
CALINE4 NOx we estimated a reduction in biparietal diameter of 0.2–0.3 mm. For women residing within 5 km of a
monitoring station, we estimated biparietal diameter reductions of 0.9–1.0 mm per IQR increase in CO and NO2. Effect
estimates were robust to adjustment for a number of potential confounders. We did not observe consistent patterns for
other growth endpoints we examined.
Conclusions: Prenatal exposure to traffic-derived pollution was negatively associated with fetal head size measured as biparietal
diameter in late pregnancy.
Ritz, B., J. Qiu, P. Lee, F. Lurmann, B. Penfold, R. E. Weiss, R. McConnell, C. Arora, C. Hobel, & M. Wilhelm (2014)
Prenatal air pollution exposure and ultrasound measures of fetal growth in Los Angeles, California, ENVIRONMENTAL RESEARCH 130:713.
Associations of PM2.5 Constituents and Sources with Hospital Admissions: Analysis of Four Counties in
Connecticut and Massachusetts (USA) for Persons ≥65 Years of Age
Abstract - Background: Epidemiological studies have demonstrated associations between short-term exposure to PM2.5 and
hospital admissions. The chemical composition of particles varies across locations and time periods. Identifying the most
harmful constituents and sources is an important health and regulatory concern. Objectives: We examined pollutant sources
for associations with risk of hospital admissions for cardiovascular and respiratory causes. Methods: We obtained PM 2.5 filter
samples for four counties in Connecticut and Massachusetts and analyzed them for PM2.5 elements. Source apportionment
was used to estimate daily PM2.5 contributions from sources (traffic, road dust, oil combustion, and sea salt as well as a
regional source representing coal combustion and other sources). Associations between daily PM2.5 constituents and sources
and risk of cardiovascular and respiratory hospitalizations for the Medicare population (> 333,000 persons ≥ 65 years of age)
were estimated with time-series analyses (August 2000--February 2004). Results: PM2.5 total mass and PM2.5 road dust
contribution were associated with cardiovascular hospitalizations, as were the PM2.5 constituents calcium, black carbon,
vanadium, and zinc. For respiratory hospitalizations, associations were observed with PM 2.5 road dust, and sea salt as well as
aluminum, calcium, chlorine, black carbon, nickel, silicon, titanium, and vanadium. Effect estimates were generally robust to
adjustment by co-pollutants of other constituents. An interquartile range increase in same-day PM2.5 road dust (1.71 μg/m3)
was associated with a 2.11% (95% CI: 1.09, 3.15%) and 3.47% (95% CI: 2.03, 4.94%) increase in cardiovascular and
respiratory admissions, respectively. Conclusions: Our results suggest some particle sources and constituents are more
harmful than others and that in this Connecticut/Massachusetts region the most harmful particles include black carbon,
calcium, and road dust PM2.5
Bell, M. L., K. Ebisu, B. P. Leaderer, J. F. Gent, H. Lee, P. Koutrakis, Y. Wang, F. Dominici, & Roger D. Peng (2014)
Associations of PM2.5 Constituents and Sources with Hospital Admissions: Analysis of Four Counties in Connecticut and Massachusetts (USA)
for Persons ≥65 Years of Age, ENVIRONMENTAL HEALTH PERSPECTIVES 122(2).
Exposure-Response Estimates for Diesel Engine Exhaust and Lung Cancer Mortality Based on Data from
Three Occupational Cohorts
Abstract - Background: Diesel engine exhaust (DEE) has recently been classified as a known human carcinogen. Objective:
We derived a meta-exposure--response curve (ERC) for DEE and lung cancer mortality and estimated lifetime excess risks
(ELRs) of lung cancer mortality based on assumed occupational and environmental exposure scenarios. Methods: We
conducted a meta-regression of lung cancer mortality and cumulative exposure to elemental carbon (EC), a proxy measure of
DEE, based on relative risk (RR) estimates reported by three large occupational cohort studies (including two studies of
workers in the trucking industry and one study of miners). Based on the derived risk function, we calculated ELRs for
several lifetime occupational and environmental exposure scenarios and also calculated the fractions of annual lung cancer
deaths attributable to DEE. Results: We estimated a lnRR of 0.00098 (95% CI: 0.00055, 0.0014) for lung cancer mortality
with each 1-μg/m3-year increase in cumulative EC based on a linear meta-regression model. Corresponding lnRRs for the
individual studies ranged from 0.00061 to 0.0012. Estimated numbers of excess lung cancer deaths through 80 years of age
for lifetime occupational exposures of 1, 10, and 25 μg/m3 EC were 17, 200, and 689 per 10,000, respectively. For lifetime
environmental exposure to 0.8 μg/m3 EC, we estimated 21 excess lung cancer deaths per 10,000. Based on broad
assumptions regarding past occupational and environmental exposures, we estimated that approximately 6% of annual lung
cancer deaths may be due to DEE exposure. Conclusions: Combined data from three U.S. occupational cohort studies
suggest that DEE at levels common in the workplace and in outdoor air appear to pose substantial excess lifetime risks of
lung cancer, above the usually acceptable limits in the United States and Europe, which are generally set at 1/1,000 and
1/100,000 based on lifetime exposure for the occupational and general population, respectively.
Vermeulen, R., D. T. Silverman, E. Garshick, J. Vlaanderen, L. Portengen, & K. Steenland (2014) Exposure-Response Estimates
for Diesel Engine Exhaust and Lung Cancer Mortality Based on Data from Three Occupational Cohorts, ENVIRONMENTAL HEALTH
PERSPECTIVES 122(2).
Addressing the Burden of Disease Attributable to Air Pollution in India: The Need to Integrate across
Household and Ambient Air Pollution Exposures
Abstract - The author reflects on the Global Burden of Disease (GBD) 2010 Project and discusses the comparative risk
assessment and air pollution in India. Topics discussed were household air pollution (HAP), ambient air pollution (AAP) in
the form of particulate matter and public health programs in India. Other topics included were air quality management and
estimation of the burden of disease from ischemic heart disease, acute lower respiratory infection and lung cancer for both
AAP and HAP.
Balakrishnan, K., A. Cohen, & K. R. Smith (2014) Addressing the Burden of Disease Attributable to Air Pollution in India: The Need
to Integrate across Household and Ambient Air Pollution Exposures, ENVIRONMENTAL HEALTH PERSPECTIVES 122(1):A6-A7.
Click Here to Return to the Table of Contents
AGRICULTURE
Reducing greenhouse gas emissions and adapting agricultural management for climate change in
developing countries: providing the basis for action
Abstract - Agriculture in developing countries has attracted increasing attention in international negotiations within the
United Nations Framework Convention on Climate Change for both adaptation to climate change and greenhouse gas
mitigation. However, there is limited understanding about potential complementarity between management practices that
promote adaptation and mitigation, and limited basis to account for greenhouse gas emission reductions in this sector. The
good news is that the global research community could provide the support needed to address these issues through further
research linking adaptation and mitigation. In addition, a small shift in strategy by the Inter- governmental Panel on Climate
Change (IPCC) and ongoing assistance from agricultural organizations could pro- duce a framework to move the research
and development from concept to reality. In turn, significant progress is possible in the near term providing the basis for
UNFCCC negotiations to move beyond discussion to action for the agricultural sector in developing countries.
Ogle, S. M., L. Olander, L. Wollenberg, T. Rosenstock, F. Tubiello, K. Paustian, L. Buendia, A. Nihart, & P. Smith (2014)
Reducing greenhouse gas emissions and adapting agricultural management for climate change in developing countries: providing the basis for action,
GLOBAL CHANGE BIOLOGY 20:1-6.
Optimizing rice yields while minimizing yield-scaled global warming potential
Abstract - To meet growing global food demand with limited land and reduced environmental impact, agricultural
greenhouse gas (GHG) emissions are increasingly evaluated with respect to crop productivity, i.e., on a yield-scaled as
opposed to area basis. Here, we compiled available field data on CH4 and N2O emissions from rice production systems to
test the hypothesis that in response to fertilizer nitrogen (N) addition, yield-scaled global warming potential (GWP) will be
minimized at N rates that maximize yields. Within each study, yield N surplus was calculated to estimate deficit or excess N
application rates with respect to the optimal N rate (defined as the N rate at which maximum yield was achieved).
Relationships between yield N surplus and GHG emissions were assessed using linear and nonlinear mixed-effects models.
Results indicate that yields increased in response to increasing N surplus when moving from deficit to optimal N rates. At N
rates contributing to a yield N surplus, N2O and yield-scaled N2O emissions increased exponentially. In contrast, CH4
emissions were not impacted by N inputs. Accordingly, yield-scaled CH4 emissions decreased with N addition. Overall, yieldscaled GWP was minimized at optimal N rates, decreasing by 21% compared to treatments without N addition. These
results are unique compared to aerobic cropping systems in which N2O emissions are the primary contributor to GWP,
meaning yield-scaled GWP may not necessarily decrease for aerobic crops when yields are optimized by N fertilizer addition.
Balancing gains in agricultural productivity with climate change concerns, this work supports the concept that high rice yields
can be achieved with minimal yield- scaled GWP through optimal N application rates. Moreover, additional improvements in
N use efficiency may further reduce yield-scaled GWP, thereby strengthening the economic and environmental sustainability
of rice systems.
Pittelkow, C. M., M. A. Adviento-Borbe, C. Van Kessel, J. E. Hill, & B. A. Linquist (2014) Optimizing rice yields while minimizing
yield-scaled global warming potential, GLOBAL CHANGE BIOLOGY.
Ruminants, climate change and climate policy
Summary - Greenhouse gas emissions from ruminant meat production are significant. Reductions in global ruminant
numbers could make a substantial contribution to climate change mitigation goals and yield important social and
environmental co-benefits…. Moving forwards, there are steps that governments and international climate negotiators can
take to curb global ruminant increases and reduce emissions from the agricultural sector. Reducing meat consumption as a
demand-side mitigation action offers greater greenhouse gas reduction potential (0.7–7.3 Gt CO2e yr−1) than the supply-side
measures of increased crop yields (0.2–1.9 Gt CO2e yr−1) or livestock feeding efficiency (0.2–1.6 Gt CO2e yr−1). In terms
of short-term climate change mitigation during the next few decades, if all the land used for ruminant livestock production
were instead converted to grow natural vegetation, increased CO2sequestration on the order of 30–470% of the greenhouse
gas emissions associated with food production could be expected. Nonetheless, policies targeting both supply-side measures
to improve agricultural production efficiencies and demand-side mitigation for encouraging behavioural changes to reduce
meat consumption (particularly ruminant meat) and waste have the best chance of providing rapid and lasting climate
benefits.
Ripple, W. J., P. Smith, H. Haberl, S. A. Montzka, C. McAlpine & D. H. Boucher (2014) Ruminants, climate change and climate
policy, NATURE CLIMATE CHANGE 4:2-5.
Click Here to Return to the Table of Contents
BIOMASS BURNING & COOKING AND HEATING
Impacts of controlling biomass burning emissions on wintertime carbonaceous aerosol in Europe
Abstract - We use a 3-D regional chemical transport model, with the latest advancements in the organic aerosol (OA)
treatment, and an updated emission inventory for wood combustion to study the organic aerosol change in response to the
replacement of current residential wood combustion technologies with pellet stoves. Simulations show a large decrease of
fine organic aerosol (more than 60%) in urban and suburban areas during winter and decreases of 30–50% in elemental
carbon levels in large parts of Europe. There is also a considerable decrease (around 40%) of oxidized OA, mostly in rural
and remote regions. Total PM2.5 mass is predicted to decrease by 15–40% on average during the winter in continental
Europe. Accurate representation of the intermediate volatility precursors of organic aerosol in the emission inventory is
crucial in assessing the efficiency of such abatement strategies.
Fountoukis, C., T. Butler, M.G. Lawrence, H.A.C. Denier van der Gon, A.J.H. Visschedijk, P. Charalampidis, C. Pilinis, &
S.N. Pandis (2014) Impacts of controlling biomass burning emissions on wintertime carbonaceous aerosol in Europe, ATMOSPHERIC
ENVIRONMENT 87:175-182.
Enablers and Barriers to Large-Scale Uptake of Improved Solid Fuel Stoves: A Systematic Review
Background: Globally, 2.8 billion people rely on household solid fuels. Reducing the resulting adverse health, environmental,
and development consequences will involve transitioning through a mix of clean fuels and improved solid fuel stoves (IS) of
demonstrable effectiveness. To date, achieving uptake of IS has presented significant challenges.
Objectives: We performed a systematic review of factors that enable or limit large-scale uptake of is in low- and middle-income
countries.
Methods: We conducted systematic searches through multidisciplinary databases, specialist web- sites, and consulting experts.
The review drew on qualitative, quantitative, and case studies and used standardized methods for screening, data extraction,
critical appraisal, and synthesis. We summarized our findings as “factors” relating to one of seven domains—fuel and
technology characteristics; household and setting characteristics; knowledge and perceptions; finance, tax, and subsidy
aspects; market development; regulation, legislation, and standards; programmatic and policy mechanisms— and also
recorded issues that impacted equity.
Results: We identified 31 factors influencing uptake from 57 studies conducted in Asia, Africa, and Latin America. All
domains matter. Although factors such as offering technologies that meet household needs and save fuel, user training and
support, effective financing, and facilitative government action appear to be critical, none guarantee success: All factors can
be influential, depending on context. The nature of available evidence did not permit further prioritization.
Conclusions: Achieving adoption and sustained use of is at a large scale requires that all factors, spanning
household/community and program/societal levels, be assessed and supported by policy. We propose a planning tool that
would aid this process and suggest further research to incorporate an evaluation of effectiveness.
Rehfuess, E. A., E. Puzzolo, D. Stanistreet, D. Pope, & .N G. Bruce (2014) Enablers and Barriers to Large-Scale Uptake of
Improved Solid Fuel Stoves: A Systematic Review, ENVIRONMENTAL HEALTH PERSPECTIVES 122(2):120-130.
Click Here to Return to the Table of Contents
REGIONAL IMPACTS
Observational determination of albedo decrease caused by vanishing Arctic sea ice
Abstract - The decline of Arctic sea ice has been documented in over 30 y of satellite passive microwave observations. The
resulting darkening of the Arctic and its amplification of global warming was hypothesized almost 50 y ago but has yet to be
verified with direct observations. This study uses satellite radiation budget measurements along with satellite microwave sea
ice data to document the Arctic-wide decrease in planetary albedo and its amplifying effect on the warming. The analysis
reveals a striking relationship between planetary albedo and sea ice cover, quantities inferred from two independent satellite
instruments. We find that the Arctic planetary albedo has decreased from 0.52 to 0.48 between 1979 and 2011,
corresponding to an additional 6.4 ± 0.9 W/m2 of solar energy input into the Arctic Ocean region since 1979. Averaged
over the globe, this albedo decrease corresponds to a forcing that is 25% as large as that due to the change in CO 2 during
this period, considerably larger than expectations from models and other less direct recent estimates. Changes in cloudiness
appear to play a negligible role in observed Arctic darkening, thus reducing the possibility of Arctic cloud albedo feedbacks
mitigating future Arctic warming.
Pistone, K., Ian Eisenman, & V. Ramanathan (2014) Observational determination of albedo decrease caused by vanishing Arctic sea ice,
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATED OF AMERICA (Early Edition).