SLCP Research Digest
(March 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
SAP Authorship...................................................................................................................................................... 5
Inhomogeneous forcing and transient climate sensitivity............................................................................................................... 5
Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive .................................................... 5
Reconciling warming trends ................................................................................................................................................................ 5
What Role for Short-Lived Climate Pollutants in Mitigation Policy? ........................................................................................... 5
How do People in Rural India Perceive Improved Stoves and Clean Fuel? Evidence from Uttar Pradesh and
Uttarakhand ............................................................................................................................................................................................ 6
An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine Particulate
Matter Exposure .................................................................................................................................................................................... 6
Where there’s smoke . . . Poor air quality is an important contributor to cardiovascular risk.................................................. 6
Data Mashups: Potential Contribution to Decision Support on Climate Change and Health ................................................. 7
The Health Implications of Fracking ................................................................................................................................................. 7
Methane ................................................................................................................................................................. 8
Addressing the Underreporting of Methane Emissions from Natural Gas Production and Thawing Permafrost .............. 8
Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential of
spaceborne lidar observations ............................................................................................................................................................. 8
Black Carbon ......................................................................................................................................................... 8
Explosive growth in African combustion emissions from 2005 to 2030..................................................................................... 8
Understanding the dynamics of black carbon and associated contaminants in glacial systems ............................................... 9
Brown carbon in the continental troposphere ................................................................................................................................. 9
Particulate matter source apportionment in Cairo: recent measurements and comparison with previous studies ............... 9
Spatial and temporal analysis of black carbon aerosols in Istanbul megacity .............................................................................. 9
Optimized method for black carbon analysis in ice and snow using the Single Particle Soot Photometer
(DISCUSSION DRAFT)................................................................................................................................................................... 10
Hydrofluorocarbons & Alternatives...................................................................................................................... 10
Growth of climate change commitments from HFC banks and emissions (DISCUSSION DRAFT) ................................ 10
A thermodynamic analysis of refrigerants: Possibilities and tradeoffs for Low-GWP refrigerants ....................................... 10
Experimental and theoretical analysis of a heat pipe heat exchanger operating with a low global warming potential
refrigerant ............................................................................................................................................................................................. 11
Tropospheric Ozone ............................................................................................................................................. 11
Interactive ozone induces a negative feedback in CO2-driven climate change simulations .................................................... 11
Long-term exposure to elevated CO2 and O3 alters aspen foliar chemistry across developmental stages ........................... 11
The role of precursor gases and meteorology on temporal evolution of O3 at a tropical location in northeast India ....... 12
Air Pollution and Health ....................................................................................................................................... 12
World Health Organization – Burden of Disease From the Joint Effects of Household and Ambient Air Pollution
for 2012 ................................................................................................................................................................................................. 12
Ground level ozone (O3) associated with radon (222Rn) and particulate matter (PM) concentrations in Bucharest
metropolitan area and adverse health effects .................................................................................................................................. 13
Toward refined estimates of ambient PM2.5 exposure: Evaluation of a physical outdoor-to-indoor transport model ...... 13
Acute effects of black carbon and PM2.5 on children asthma admissions: A time-series study in a Chinese city ............... 13
Association of short-term increases in ambient air pollution and timing of initial asthma diagnosis among medicaidenrolled children in a metropolitan area .......................................................................................................................................... 14
Characteristics of indoor air pollution in rural mountainous and rural coastal communities in Indonesia.......................... 14
Agriculture ............................................................................................................................................................ 14
Climate change mitigation through livestock system transitions ................................................................................................. 14
Agriculture: Steps to sustainable livestock ...................................................................................................................................... 15
Stable carbon isotopes of methane for real-time process monitoring in anaerobic digesters ................................................ 15
Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation............................................ 15
In vitro screening of selected feed additives, plant essential oils and plant extracts for rumen methane mitigation ............ 16
Effect of SRI Water Management On Water Quality and Greenhouse Gas Emissions in Korea ........................................ 16
Methane production and methanogenic archaeal communities in two types of paddy soil amended with different
amounts of rice straw ......................................................................................................................................................................... 16
Effects of no-till duration on the methane oxidation capacity of Alfisols ................................................................................. 17
A simplified method for the design and sizing of anaerobic digestion systems for smaller farms ........................................ 17
Abundance of Methanogens, Methanotrophic Bacteria, and Denitrifiers in Rice Paddy Soils .............................................. 17
Microbial community structure of a pilot-scale thermophilic anaerobic digester treating poultry litter ............................... 18
Biomass Burning & Cooking and Heating .......................................................................................................... 18
How many replicate tests are needed to test cookstove performance and emissions? — Three is not always
adequate ................................................................................................................................................................................................ 18
Wildland fire emissions, carbon, and climate: Emission factors ................................................................................................. 19
Influence of open vegetation fires on black carbon and ozone variability in the southern Himalayas (NCO-P, 5079
m a.s.l.) .................................................................................................................................................................................................. 19
Indoor air pollution in slum neighbourhoods of Addis Ababa, Ethiopia.................................................................................. 19
Impact of operating wood-burning fireplace ovens on indoor air quality ................................................................................. 19
Waste ..................................................................................................................................................................... 20
Greenhouse Gas Emission and Energy Consumption in Wastewater Treatment Plants: Impact of Operating
Parameters ............................................................................................................................................................................................ 20
Optimal landfill gas utilization for renewable energy production ............................................................................................... 20
Prediction of methane production in wastewater treatment facility: a data-mining approach ............................................... 20
Improving the Energy Balance of an Integrated Microalgal Wastewater Treatment Process ................................................ 21
Fossil Fuels ........................................................................................................................................................... 21
Application of in-seam directional drilling technology for gas drainage with benefits to gas outburst control and
greenhouse gas reductions in Daning coal mine, China ............................................................................................................... 21
Drilling into controversy: the educational complexity of shale gas development .................................................................... 21
The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a
panel of developed countries ............................................................................................................................................................. 22
Transport .............................................................................................................................................................. 22
PM2.5: global progress in controlling the motor vehicle contribution ........................................................................................ 22
Vulnerable Regions ............................................................................................................................................... 22
Climate trends in the Arctic as observed from space .................................................................................................................... 23
Annual distributions and sources of Arctic aerosol components, aerosol optical depth, and aerosol absorption.............. 23
An AeroCom assessment of black carbon in Arctic snow and sea ice ....................................................................................... 23
Cross Cutting ........................................................................................................................................................ 24
New Directions: Support for integrated decision-making in air and climate policies - Development of a metricsbased information portal .................................................................................................................................................................... 24
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SAP AUTHORSHIP
Inhomogeneous forcing and transient climate sensitivity
Abstract - Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario.
Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into
account the reduced warming rates during the past 10–15 years during which forcing has increased markedly. In contrast,
comparisons of modelled feedback processes with observations indicate that the most realistic models have higher
sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient
climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This
enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high
latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement
largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2
in present models and assessments (<1.3 °C) is very unlikely.
Shindell, D. T. (2014) Inhomogeneous forcing and transient climate sensitivity, NATURE CLIMATE CHANGE 4:274-277.
Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive
Abstract - We present a description of the ModelE2 version of the Goddard Institute for Space Studies (GISS) General
Circulation Model (GCM) and the configurations used in the simulations performed for the Coupled Model Intercomparison
Project Phase 5 (CMIP5). We use six variations related to the treatment of the atmospheric composition, the calculation of
aerosol indirect effects, and ocean model component. Specifically, we test the difference between atmospheric models that
have noninteractive composition, where radiatively important aerosols and ozone are prescribed from precomputed decadal
averages, and interactive versions where atmospheric chemistry and aerosols are calculated given decadally varying emissions.
The impact of the first aerosol indirect effect on clouds is either specified using a simple tuning, or parameterized using a
cloud microphysics scheme. We also use two dynamic ocean components: the Russell and HYbrid Coordinate Ocean Model
(HYCOM) which differ significantly in their basic formulations and grid. Results are presented for the climatological means
over the satellite era (1980–2004) taken from transient simulations starting from the preindustrial (1850) driven by estimates
of appropriate forcings over the 20th Century. Differences in base climate and variability related to the choice of ocean
model are large, indicating an important structural uncertainty. The impact of interactive atmospheric composition on the
climatology is relatively small except in regions such as the lower stratosphere, where ozone plays an important role, and the
tropics, where aerosol changes affect the hydrological cycle and cloud cover. While key improvements over previous versions
of the model are evident, these are not uniform across all metrics.
Schmidt, G. A., M. Kelley, L. Nazarenko, R. Ruedy, G. L. Russell, I. Aleinov, M. Bauer, S. E. Bauer, M. K. Bhat, R. Bleck, V.
Canuto, Y. Chen, Y. Cheng, T. L. Clune, A. D. Genio, R. de Fainchtein, G. Faluvegi, J. E. Hansen, R. J. Healy, N. Y. Kiang,
D. Koch, A. A. Lacis, A. N. LeGrande, J. Lerner, K. K. Lo, E. E. Matthews, S. Menon, R. L. Miller, V. Oinas, A. O. Oloso,
J. P. Perlwitz, M. J. Puma, W. M. Putman, D. Rind, A. Romanou, M. Sato, D. T. Shindell, S. Sun, R. A. Syed, N. Tausnev, K.
Tsigaridis, N. Unger, A. Voulgarakis, M. Yao, & J. Zhang (2014) Configuration and assessment of the GISS ModelE2 contributions to
the CMIP5 archive, JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 6.
Reconciling warming trends
Intro - Climate models projected stronger warming over the past 15 years than has been seen in observations. Conspiring
factors of errors in volcanic and solar inputs, representations of aerosols, and El Niño evolution, may explain most of the
discrepancy.
Schmidt, G. A., D. T. Shindell, & K. Tsigaridis (2014) Reconciling warming trends, NATURE GEOSCIENCE 7:158-160.
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 CO 2, 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.
How do People in Rural India Perceive Improved Stoves and Clean Fuel? Evidence from Uttar Pradesh
and Uttarakhand
Abstract - Improved cook stoves (ICS) have been widely touted for their potential to deliver the triple benefits of improved
household health and time savings, reduced deforestation and local environmental degradation, and reduced emissions of
black carbon, a significant short-term contributor to global climate change. Yet diffusion of ICS technologies among
potential users in many low-income settings, including India, remains slow, despite decades of promotion. This paper
explores the variation in perceptions of and preferences for ICS in Uttar Pradesh and Uttarakhand, as revealed through a
series of semi-structured focus groups and interviews from 11 rural villages or hamlets. We find cautious interest in new ICS
technologies, and observe that preferences for ICS are positively related to perceptions of health and time savings. Other
respondent and community characteristics, e.g., gender, education, prior experience with clean stoves and institutions
promoting similar technologies, and social norms as perceived through the actions of neighbours, also appear important.
Though they cannot be considered representative, our results suggest that efforts to increase adoption and use of ICS in
rural India will likely require a combination of supply-chain improvements and carefully designed social marketing and
promotion campaigns, and possibly incentives, to reduce the up-front cost of stoves.
Bhojvaid, V., M. Jeuland, A. Kar, J. J. Lewis, S. K. Pattanayak, N. Ramanathan, V. Ramanathan, & I. H. Rehman (2014) How
do People in Rural India Perceive Improved Stoves and Clean Fuel? Evidence from Uttar Pradesh and Uttarakhand, INT. J. ENVIRON. RES.
PUBLIC HEALTH 11:1341-1358.
An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine
Particulate Matter Exposure
Abstract - Background: Estimating the burden of disease attributable to long-term exposure to fine particulate matter
(PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk function (RR). However,
there is inadequate direct evidence to identify the shape of the mortality RR functions at high ambient concentrations
observed in many places in the world. Objective: Develop relative risk (RR) functions over entire global exposure range for
causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary
disease (COPD), and lung cancer (LC). In addition, develop RR functions for the incidence of acute lower respiratory
infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children less than 5 years old.
Methods: An Integrated Exposure-Response (IER) model was fit by integrating available RR information from studies of
ambient air pollution (AAP), second hand tobacco smoke (SHS), household solid cooking fuel (HAP), and active smoking
(AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass.
Population attributable fractions (PAF) were derived for every country based on estimated world-wide ambient PM2.5
concentrations. Results: The IER model was a superior predictor of RR compared to seven other forms previously used in
burden assessments. The PAF (%) attributable to AAP exposure varied among countries from: 2-41 for IHD, 1-43 for
stroke, < 1-21 for COPD, < 1-25 for LC, and < 1-38 for ALRI. Conclusions: We developed a fine particulate mass-based
RR model that covered the global range of exposure by integrating RR information from different combustion types that
generate emissions of particulate matter. The model can be updated as new RR information becomes available.
Burnett, R. T., C. A. Pope III, M. Ezzati, C. Olives, S. S. Lim, S. Mehta, H. H. Shin, G. Singh, B. Hubbell, M. Brauer, H. R.
Anderson, K. R. Smith, J. R. Balmes, N. G. Bruce, H. Kan, F. Laden, A. Prüss-Ustün, M. C. Turner, S. M. Gapstur, W. R.
Diver, & A. Cohen (2014) An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine
Particulate Matter Exposure, ENVIRONMENTAL HEALTH PERSPECTIVES.
Where there’s smoke . . . Poor air quality is an important contributor to cardiovascular risk
Introduction - Air pollution has received much attention in the past year. The Global Burden of Disease Study estimated
that 3.2 million deaths a year are attributable to particulate matter in outdoor air, the International Agency for Research on
Cancer classified polluted outdoor air as carcinogenic, and we witnessed extreme episodes in Beijing and Shanghai. While
effects on respiratory health have long been recognised, it is the impacts on cardiovascular disease that are responsible for
most of the disease burden attributable to air pollution. Two linked papers provide new insight into the role of air pollution
on cardiovascular disease and subsequent impacts on population health.
Brauer, M., & G. B. J. Mancini (2014) Where there’s smoke . . . Poor air quality is an important contributor to cardiovascular risk, BMJ
348:40.
Data Mashups: Potential Contribution to Decision Support on Climate Change and Health
Abstract - Linking environmental, socioeconomic and health datasets provides new insights into the potential associations
between climate change and human health and wellbeing, and underpins the development of decision support tools that will
promote resilience to climate change, and thus enable more effective adaptation. This paper outlines the challenges and
opportunities presented by advances in data collection, storage, analysis, and access, particularly focusing on “data mashups”.
These data mashups are integrations of different types and sources of data, frequently using open application programming
interfaces and data sources, to produce enriched results that were not necessarily the original reason for assembling the raw
source data. As an illustration of this potential, this paper describes a recently funded initiative to create such a facility in the
UK for use in decision support around climate change and health, and provides examples of suitable sources of data and the
purposes to which they can be directed, particularly for policy makers and public health decision makers.
Fleming, L. E., A. H. B. Golding, A. Kessel, A. Cichowska, C. E. Sabel, M. H. Depledge, C. Sarran, N. J. Osborne, C. Whitmore, N.
Cocksedge, & D. Bloomfield (2014) Data Mashups: Potential Contribution to Decision Support on Climate Change and Health, INT. J.
ENVIRON. RES. PUBLIC HEALTH 11(2):1725-1746.
The Health Implications of Fracking
Intro - What is known about the health effects of gas extraction by induced hydraulic fracturing of gas-bearing rock — ie,
fracking? A workshop held on Nov 15, 2013, at the London School of Hygiene and Tropical Medicine and attended by
scientists, public health professionals, and decision makers addressed this question.
Kovats, S., M. Depledge, A. Haines, L. E Fleming, P. Wilkinson, S. B Shonkoff, & N. Scovronick (2014) The Health
Implications of Fracking, THE LANCET 383(9919):757-758.
Transport for Health: The Global Burden of Disease From Motorized Road Transport
Executive Summary - This report quantifies, for the first time, the global health loss from injuries and air pollution that can
be attributed to motorized road transport. It combines estimates of the global burden of road injuries based on a large pool
of new data from the most information-poor regions with estimates of the health effects of pollution from vehicles. The
results of this analysis show the following: Pollution from vehicles is the cause of 184,000 deaths globally, including 91,000
deaths from ischemic heart disease, 59,000 deaths from stroke, and 34,000 deaths from lower respiratory infections, chronic
obstructive pulmonary disease, and lung cancer.
WORLD BANK & INSTITUTE FOR HEALTH METRICS AND EVALUATION, TRANSPORT FOR HEALTH: THE GLOBAL BURDEN
OF DISEASE FROM MOTORIZED ROAD TRANSPORT (2014) (lead authors: Kavi Bhalla, Marc Shotten, Aaron Cohen, Michael
Brauer, Saeid Shahraz, Richard Burnett, Katherine Leach-Kemon, Greg Freedman, Christopher J.L. Murray).
Effects on Well-Being of Investing in Cleaner Air in India
Abstract - Over the past decade, India has experienced rapid economic growth along with increases in levels of air pollution.
Our goal is to examine how alternative policies for air pollution abatement affect well-being there. In particular, we estimate
the effects of policies to reduce the levels of ambient fine particulates (PM2.5), which are especially harmful to human health,
on well-being, quantified using the United Nation’s human development index (HDI). Two of the three dimensions of this
index are based on the gross domestic product (GDP) per capita and life expectancy. Our approach allows reductions in
PM2.5 to affect both of them. In particular, economic growth is affected negatively through the costs of the additional
pollution control measures and positively through the increased productivity of the population. We consider three scenarios
of PM2.5 abatement, corresponding to no further control, current Indian legislation, and current European legislation. The
overall effect in both control scenarios is that growth in GDP is virtually unaffected relative to the case of no further
controls, life expectancy is higher, and well-being, as measured by the HDI, is improved. In India, air pollution abatement
investments clearly improve well-being.
Sanderson, W., E. Striessnig, W. Schopp, & M. Amann (2013) Effects on Well-Being of Investing in Cleaner Air in India,
ENVIRONMENTAL SCIENCE & TECHNOLOGY.
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METHANE
Addressing the Underreporting of Methane Emissions from Natural Gas Production and Thawing
Permafrost
Abstract - Reductions of methane, black carbon and tropospheric ozone could halve warming during the 2030s, while a
fairly aggressive strategy to reduce carbon dioxide would do little over the next 20–30 years. Concerning methane,
governments must act quickly to take advantage of this opportunity. Production of ‘unconventional’ natural gas, such as
shale gas, has increased significantly and with conventional sources could meet current consumption levels for over 240
years. However, the benefit of methane as a transitional fuel from coal to renewables is questionable due to methane leakage
during production. Also, rising temperatures are releasing methane from melting permafrost, but governments are not
required to report these emissions. Thus, countries are farther from meeting their targets and the global community is farther
from reaching the goal of limiting warming to 2°C above pre-industrial levels than emissions data suggest. This article
establishes an agenda for fuller accounting of methane in the climate change regime.
Wold, C., V. Johnson, & B. Saver (2014) Addressing the Underreporting of Methane Emissions from Natural Gas Production and
Thawing Permafrost, REVIEW OF EUROPEAN, COMPARATIVE & INTERNATIONAL ENVIRONMENTAL LAW (Early view).
Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential
of spaceborne lidar observations
Abstract – We investigate the sensitivity of future spaceborne lidar measurements to changes in surface methane emissions.
We use surface methane observations from nine European ground stations and a Lagrangian transport model to infer
surface methane emissions for 2010. Our inversion shows the strongest emissions from the Netherlands, the coal mines in
Upper Silesia, Poland, and wetlands in southern Finland. The simulated methane surface concentrations capture at least half
of the daily variability in the observations, suggesting that the transport model is correctly simulating the regional transport
pathways over Europe. With this tool we can test whether proposed methane lidar instruments will be sensitive to changes in
surface emissions. We show that future lidar instruments should be able to detect a 50% reduction in methane emissions
from the Netherlands and Germany, at least during summer.
Weaver, C., C. Kiemle, S. R. Kawa, T. Aalto, J. Necki, M. Steinbacher, J. Arduini, F. Apadula, H. Berkhout, & J. Hatakka,
Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential of spaceborne lidar observations, ATMOS.
CHEM. PHYS. 14:2625-2637 (2014).
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BLACK CARBON
Explosive growth in African combustion emissions from 2005 to 2030
Abstract - Emissions of gases and particles from the combustion of fossil fuels and biofuels in Africa are expected to
increase significantly in the near future due to the rapid growth of African cities and megacities. There is currently no
regional emissions inventory that provides estimates of anthropogenic combustion for the African continent. This work
provides a quantification of the evolution of African combustion emissions from 2005 to 2030, using a bottom-up method.
This inventory predicts very large increases in black carbon, organic carbon, CO, NOx, SO2 and non-methane hydrocarbon
emissions if no emission regulations are implemented. This paper discusses the effectiveness of scenarios involving certain
fuels, specific to Africa in each activity sector and each region (western, eastern, northern and southern Africa), to reduce the
emissions. The estimated trends in African emissions are consistent with emissions provided by global inventories, but they
display a larger range of values. African combustion emissions contributed significantly to global emissions in 2005. This
contribution will increase more significantly by 2030: organic carbon emissions will for example make up 50% of the global
emissions in 2030. Furthermore, we show that the magnitude of African anthropogenic emissions could be similar to African
biomass burning emissions around 2030.
Liousse, C., E. Assamoi, P. Criqui, C. Granier & R. Rosset (2014) Explosive growth in African combustion emissions from 2005 to
2030, ENVIRONMENTAL RESEARCH LETTERS 9:1-10.
Understanding the dynamics of black carbon and associated contaminants in glacial systems
Abstract - More than one billion people depend upon glaciers for water, yet this exploitation is seldom underpinned by
science-led water management practice. Previous work has detected that glaciers store and then subsequently release
contaminants to downstream ecosystems, revealing a potentially harmful legacy that needs to be managed in conjunction
with contemporary atmospheric pollution and climate change. Remarkably, while several classes of harmful organic
pollutants have been considered in this context, almost no attention has been given to black carbon, a dark aerosol that is
host to several adsorbed contaminants and that greatly increases glacier melt by enhancing the absorption of solar radiation.
The future impact of black carbon upon glacier melt and contaminant release cannot be managed until we know how much
historical black carbon is stored in Earth's glaciers. Further, as the residence time of ice within many mountain glaciers is
between 100 and 1000 years, major changes in these impacts can be anticipated in the near future. A case is therefore made
for using glacier dynamic models to understand the distribution of postindustrial, contaminated ice within glaciers, so that
their impacts upon melt water quantity and quality can be forecast. A research framework is proposed that ranges from high
flux, dynamic glaciers which are replete with postindustrial ice, to low flux, polar glaciers which are unlikely to become
replete before they disappear. Research into the processing of contaminants following their melt-out is also required, because
microbial processes will lead to their bioflocculation and biodegradation on glacier surfaces.
Hodson, A. J. (2014) Understanding the dynamics of black carbon and associated contaminants in glacial systems, WILEY
INTERDISCIPLINARY REVIEWS: WATER 1(2):141-149.
Brown carbon in the continental troposphere
Abstract - Little is known about the optical significance of light absorbing particulate organic compounds (i.e., brown
carbon, BrC), including the importance relative to black carbon (BC) and influence on direct radiative forcing by aerosols.
The vertical profile of BrC affects its radiative forcing, yet the distribution of BrC in the free troposphere is largely unknown.
In this study, BrC absorption was directly measured in solvent extracts of particulate filters obtained from aircraft sampling
over the continental USA. Excluding biomass burning plumes, BrC was observed throughout the tropospheric column
(<13 km), and its prevalence increased relative to BC with increasing altitude, indicating contributions from secondary
sources. Closure analysis showed good agreement between light absorption from BC plus BrC relative to measured total
aerosol absorption. A radiative transfer model indicated that BrC absorption reduced top of atmosphere aerosol forcing by
~20%, suggesting that it is an important component of direct aerosol radiative forcing
Liu, J., E. Scheuer, J. Dibb, L. D. Ziemba, K. L. Thornhill, B. E. Anderson, A. Wisthaler, T. Mikoviny, J. J. Devi, M. Bergin,
& R. J. Weber (2014) Brown carbon in the continental troposphere, GEOPHYSICAL RESEARCH LETTERS (Early View).
Particulate matter source apportionment in Cairo: recent measurements and comparison with previous
studies
Abstract - This paper presents results of an atmospheric particulate matter (PM) monitoring and source apportionment
study conducted during summer and fall 2010 in Cairo. These results are compared to those of similar studies in 1999 and
2002. Concentrations of PM2.5 and PM10 mass and their chemical constituents were determined and chemical mass balance
modeling was conducted to estimate the source contributions to ambient PM. Emphasis was placed on characterizing the
long-term trends in atmospheric lead (Pb) concentrations and their sources in Cairo. PM2.5 and PM10 concentrations were
highest during fall 1999 at four of the five study sites. This was also the case for open (vegetative/trash) burning
contributions, which showed a smaller increase during fall 2010. Burning of agricultural waste after the fall harvest continues
to be a major source of PM in Cairo. Both PM2.5 and PM10 mass decreased dramatically at Shobra, an industrial site, from
1999 to 2010. A reduction of lead smelting has resulted in a decrease of ambient Pb concentrations of up to two orders of
magnitude from 1999 to 2010 at Shobra, El-Zamalek, and El-Qualaly. From 1999 to 2010, the mobile source contribution
has been relatively stable at most of the study sites. Future efforts to reduce ambient PM should focus on controlling
emissions from motor vehicles and open burning and implementing mitigation strategies for reducing resuspended road and
construction dust.
Lowenthal, D. H., A. W. Gertler, & M. W. Labib (2014) Particulate matter source apportionment in Cairo: recent measurements and
comparison with previous studies, INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY 11(3):657-670.
Spatial and temporal analysis of black carbon aerosols in Istanbul megacity
Abstract - Black carbon (BC) is an important component of particulate matter due to its effects on human health and
climate. In this study, we present the first BC concentrations measured in the Istanbul megacity (~ 15 million inhabitants).
Two measurement campaigns have been conducted to measure BC and fine particulate matter (PM2.5) concentrations at four
locations, characterized by different traffic densities. In the first campaign, BC daily mean concentrations have been found to
be between 4 μg/m3 and 10 μg/m3. In the second campaign, BC and PM2.5 have been measured at the site with the highest
traffic density for an entire year. Annually averaged BC contributes by 38 ± 14% to the PM2.5 levels (annual average BC:
13 μg/m3 and PM2.5: 36 μg/m3). Diurnal variations of BC concentrations followed those of traffic density (correlation
coefficient of 0.87). These measurements are essential to identify the sources of BC and PM 2.5 concentrations in Istanbul and
develop mitigation measures.
Ozdemir, H., L. Pozzoli, T. Kindap, G. Demir, B. Mertoglu, N. Mihalopoulos, C. Theodosi, M. Kanakidou, U. Im, A. Unal
(2014) Spatial and temporal analysis of black carbon aerosols in Istanbul megacity, SCIENCE OF THE TOTAL ENVIRONMENT 473–
474:451-458.
Optimized method for black carbon analysis in ice and snow using the Single Particle Soot Photometer
Abstract - In this study we attempt to optimize the method for measuring black carbon (BC) in snow and ice using a single
particle soot photometer (SP2). Beside the previously applied ultrasonic (CETAC) and Collison-type nebulizers we introduce
a jet (APEX-Q) nebulizer to aerosolize the aqueous sample for SP2 analysis. Both CETAC and APEX-Q require small
sample volumes (few milliliters) which makes them suitable for ice core analysis. The APEX-Q shows the least sizedependent nebulizing efficiency in the BC particle diameter range of 100–1000 nm. The CETAC has the advantage that air
and liquid flows can be monitored continuously. All nebulizer-types require a calibration with BC standards for the
determination of the BC mass concentration in unknown aqueous samples. We found Aquadag to be a suitable material for
preparing calibration standards. Further, we studied the influence of different treatments for fresh discrete snow and ice
samples as well as the effect of storage. The results show that samples are best kept frozen until analysis. Once melted, they
should be sonicated for 25 min, immediately analyzed while being stirred and not be refrozen.
Wendl, I. A., J. A. Menking, R. Färber, M. Gysel, S. D. Kaspari, M. J. G. Laborde, & M. Schwikowski (2014) Optimized method
for black carbon analysis in ice and snow using the Single Particle Soot Photometer, ATMOS. MEAS. TECH. DISCUSS. 7:3075-3111.
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HYDROFLUOROCARBONS & ALTERNATIVES
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 emission 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.
A thermodynamic analysis of refrigerants: Possibilities and tradeoffs for Low-GWP refrigerants
Abstract - We explore the possibilities for refrigerants having low global warming potential (GWP). A set of about 1200
candidate fluids is identified from more than 56 000 small molecules examined by applying screening criteria to estimates for
GWP, flammability, stability, toxicity, and critical temperature. Methodologies for this screening have been presented in
earlier works and are summarized here. The fluids with critical temperatures between 300 K and 400 K (i.e., those that could
be used in current types of equipment with minor modifications) number 62. The fluids include halogenated olefins;
compounds containing oxygen, nitrogen, or sulfur; as well as carbon dioxide. We discuss the tradeoffs presented by these 62
candidates, considering their thermodynamic properties and their stability and toxicity characteristics. No fluid is ideal in all
regards—all have one or more negative attributes: poor thermodynamic properties, toxicity, chemical instability, low to
moderate flammability, or very high operating pressures.
McLinden, M. O., A. F. Kazakov, J. S. Brown, & P. A. Domanski (2014) A thermodynamic analysis of refrigerants: Possibilities and
tradeoffs for Low-GWP refrigerants, INTERNATIONAL JOURNAL OF REFRIGERATION 38:80-92.
Experimental and theoretical analysis of a heat pipe heat exchanger operating with a low global warming
potential refrigerant
Abstract - In the present paper the experimental and theoretical analysis of a Heat Pipe Heat Exchanger (HPEH) is
reported. The HPHE consists of 54 horizontal 12.7 mm micro-fin copper tubes 700 mm in length and aluminium
continuous fins 0.115 mm in thickness with 3 mm of fin spacing. The HPHE presents an evaporator section of 270 mm, a
condenser section of 270 mm and adiabatic section of 160 mm. The performance of the heat exchanger operating with the
well-known hydrofluorocarbon refrigerant HFC134a is compared with the results obtained using the new low global
warming potential hydrofluoro-olefin HFO1234ze(E). Tests were run in a double wind channel with air operating conditions
typical for air-conditioning in European countries for both summer and winter seasons. The consistency of the experimental
results is proved by the comparison with a semi-empirical model of the heat exchanger based on heat transfer correlations
available in literature.
Longo, G. A., G. Righetti, C. Zilio, & F. Bertolo (2014) Experimental and theoretical analysis of a heat pipe heat exchanger operating
with a low global warming potential refrigerant, APPLIED THERMAL ENGINEERING 65(1-2):361-368.
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TROPOSPHERIC OZONE
Interactive ozone induces a negative feedback in CO2-driven climate change simulations
Abstract - Interactively coupled climate chemistry models (CCMs) extend the number of feedback mechanisms in climate
change simulations by including chemical feedback. In this study the radiative feedback from ozone changes on climate
response and climate sensitivity is quantified for a series of simulations driven by CO 2 increases on top of a present-day
reference concentration level. Other possibly relevant feedback via atmospheric chemistry, e.g., via CH4 and N2O, is not fully
quantified in the CCM setup as their concentrations are essentially fixed at the surface. In case of a CO 2-doubling simulation,
the ozone feedback reduces the climate sensitivity parameter by 3.4%, from 0.70 K/(W m−2) without interactive chemistry to
0.68 K/(W m−2). In case of a 4*CO2 simulation, the reduction of the climate sensitivity parameter increases to 8.4%. An
analysis of feedback reveals that the negative feedback of stratospheric ozone and the associated negative feedback change in
stratospheric water vapor are mainly responsible for this damping. The feedback from tropospheric ozone changes is
positive but much smaller. The nonlinearity in the climate sensitivity damping with increased CO2 concentrations is shown to
be due to nonlinear feedback of ozone and stratospheric water vapor.
Dietmüller, S., M. Ponater, & R. Sausen (2014) Interactive ozone induces a negative feedback in CO2-driven climate change simulations,
JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES 119(4):1796-1805.
Long-term exposure to elevated CO2 and O3 alters aspen foliar chemistry across developmental stages
Abstract - Anthropogenic activities are altering levels of greenhouse gases to the extent that multiple and diverse ecosystem
processes are being affected. Two gases that substantially influence forest health are atmospheric carbon dioxide (CO2) and
tropospheric ozone (O3). Plant chemistry will play an important role in regulating ecosystem processes in future
environments, but little information exists about the longitudinal effects of elevated CO2 and O3 on phytochemistry, especially
for long-lived species such as trees. To address this need, we analysed foliar chemical data from two genotypes of trembling
aspen, Populus tremuloides, collected over 10 years of exposure to levels of CO2 and O3 predicted for the year 2050. Elevated
CO2 and O3 altered both primary and secondary chemistry, and the magnitude and direction of the responses varied across
developmental stages and between aspen genotypes. Our findings suggest that the effects of CO2 and O3 on phytochemical
traits that influence forest processes will vary over tree developmental stages, highlighting the need to continue long-term,
experimental atmospheric change research.
Couture, J. J., L. M. Holeski, & R. L. Lindroth (2014) Long-term exposure to elevated CO2 and O3 alters aspen foliar chemistry across
developmental stages, PLANT, CELL & ENVIRONMENT 37(3):758-765.
The role of precursor gases and meteorology on temporal evolution of O3 at a tropical location in northeast
India
Abstract - South Asia, particularly the Indo-Gangetic Plains and foothills of the Himalayas, has been found to be a major
source of pollutant gases and particles affecting the regional as well as the global climate. Inventories of greenhouse gases for
the South Asian region, particularly the sub-Himalayan region, have been inadequate. Hence, measurements of the gases are
important from effective characterization of the gases and their climate effects. The diurnal, seasonal, and annual variation of
surface level O3 measured for the first time in northeast India at Dibrugarh (27.4°N, 94.9 E, 111 m amsl), a sub-Himalayan
location in the Brahmaputra basin, from November 2009 to May 2013 is presented. The effect of the precursor gases NO x
and CO measured simultaneously during January 2012–May 2013 and the prevailing meteorology on the growth and decay
of O3 has been studied. The O3 concentration starts to increase gradually after sunrise attaining a peak level around 1500
hours LT and then decreases from evening till sunrise next day. The highest and lowest monthly maximum concentration of
O3 is observed in March (42.9 ± 10.3 ppb) and July (17.3 ± 7.0 ppb), respectively. The peak in O3 concentration is preceded
by the peaks in NO x and CO concentrations which maximize during the period November to March with peak values of
25.2 ± 21.0 ppb and 1.0 ± 0.4 ppm, respectively, in January. Significant nonlinear correlation is observed between O 3 and
NO, NO2, and CO. National Atmospheric and Oceanic Administration Hybrid Single-Particle Lagrangian Integrated
Trajectory back-trajectory and concentration weighted trajectory analysis carried out to delineate the possible airmass
trajectory and to identify the potential source region of NOx and O3 concentrations show that in post-monsoon and winter,
majority of the trajectories are confined locally while in pre-monsoon and monsoon, these are originated at the IndoGangetic plains, Bangladesh, and Bay of Bengal.
Bhuyan, Pradip Kumar, Chandrakala Bharali, Binita Pathak, & Gayatry Kalita, The role of precursor gases and meteorology on
temporal evolution of O3 at a tropical location in northeast India, ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH (2014).
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AIR POLLUTION AND HEALTH
World Health Organization – Burden of Disease From the Joint Effects of Household and Ambient Air
Pollution for 2012
In new estimates released, WHO reports that in 2012 around 7 million people died - one in eight of total global deaths – as a
result of air pollution exposure. This finding more than doubles previous estimates and confirms that air pollution is now the
world’s largest single environmental health risk. Reducing air pollution could save millions of lives.
World Health Organization, FREQUENTLY ASKED QUESTIONS – AMBIENT AND HOUSEHOLD AIR POLLUTION AND
HEALTH UPDATE 2014 (2014).
Ambient Air Pollution - Globally, 3.7 million deaths were attributable to ambient air pollution (AAP) in 2012. About 88%
of these deaths occur in low- and middle-income (LMI) countries, which represent 82% of the world population. The
Western Pacific and South East Asian regions bear most of the burden with 1.67 million and 936’000 deaths, respectively.
About 236’000 deaths occur in the Eastern Mediterranean region, 200’000 in Europe, 176’000 in Africa, and 58’000 in the
Americas. The remaining deaths occur in high-income countries of Europe (280’000), Americas (94’000), Western Pacific
(67’000), and Eastern Mediterranean (14’000).
AAP Effects Results Summary Available here
Household Air Pollution - Globally, 4.3 million deaths were attributable to household air pollution (HAP) in 2012, almost
all in low and middle income (LMI) countries. The South East Asian and Western Pacific regions bear most of the burden
with 1.69 and 1.62 million deaths, respectively. Almost 600’000 deaths occur in Africa, 200’000 in the Eastern Mediterranean
region, 99’000 in Europe and 81’000 in the Americas. The remaining 19’000 deaths occur in high income countries.
HAP Effects Results Summary Available here
Joint Effects of HAP & AAP - Globally, 7 million deaths were attributable to the joint effects of household (HAP) and
ambient air pollution (AAP) in 2012. The Western Pacific and South East Asian regions bear most of the burden with 2.8
and 2.3 million deaths, respectively. Almost 680’000 deaths occur in Africa, about 400’000 in the Eastern Mediterranean
region, 287’000 in Europe and 131’000 in the Americas. The remaining deaths occur in high-income countries of Europe
(295’000), Americas (96’000), Western Pacific (68’000), and Eastern Mediterranean (14’000).
Joint Effects Results Summary Available here
Ground level ozone (O3) associated with radon (222Rn) and particulate matter (PM) concentrations in
Bucharest metropolitan area and adverse health effects
Abstract - The aim of this paper is to contribute with new information in the application of ground based radon ( 222Rn)
observations to atmospheric research, namely its relation with air pollution due to ground-level ozone (O3) and particle
matter in two size fractions (PM10 and PM2.5) for Bucharest metropolitan area in Romania. During January 1–December
31, 2011, ground levels of radon, ozone and particulate matter (PM) have been continuously monitored in synergy with the
main meteorological parameters (air temperature, humidity and pressure), and daily global air quality indices. A systematic
analysis of surface ozone observations of ground level radon, ozone and PM is presented. Observational results indicate the
following yearly daily mean ground level concentrations: 40.26 ± 7.54 Bq/m3 for radon, 90.51 μg/m3 for ozone,
35.96 μg/m3 for PM2.5, and 40.91 μg/m3 for PM10. The assessment of the results showed the influence of local and
meteorological conditions on the daily mean radon, ozone and PM concentrations. However, in densely populated
metropolitan area of Bucharest the mean daily values of ozone, PM2.5, PM10, and attached 222Rn are sometimes higher than
European Community limit values leading to serious public concern during the last years. Due to the high risk of increased
levels of O3, PM2.5, PM10, and attached 222Rn on human health respiratory function (especially for children and older
persons), and urban green, the results are very useful for atmospheric, radiological protection, epidemiological and
environmental studies.
Zoran, M., M. R. Dida, R. Savastru, D. Savastru, A. Dida, & O. Ionescu (2014) Ground level ozone (O3) associated with radon
(222Rn) and particulate matter (PM) concentrations in Bucharest metropolitan area and adverse health effects, JOURNAL OF
RADIOANALYTICAL AND NUCLEAR CHEMISTRY.
Toward refined estimates of ambient PM2.5 exposure: Evaluation of a physical outdoor-to-indoor transport
model
Abstract - Because people spend the majority of their time indoors, the variable efficiency with which ambient PM 2.5
penetrates and persists indoors is a source of error in epidemiologic studies that use PM 2.5 concentrations measured at
central-site monitors as surrogates for ambient PM2.5 exposure. To reduce this error, practical methods to model indoor
concentrations of ambient PM2.5 are needed. Toward this goal, we evaluated and refined an outdoor-to-indoor transport
model using measured indoor and outdoor PM2.5 species concentrations and air exchange rates from the Relationships of
Indoor, Outdoor, and Personal Air Study. Herein, we present model evaluation results, discuss what data are most critical to
prediction of residential exposures at the individual-subject and populations levels, and make recommendations for the
application of the model in epidemiologic studies. This paper demonstrates that not accounting for certain human activities
(air conditioning and heating use, opening windows) leads to bias in predicted residential PM 2.5 exposures at the individualsubject level, but not the population level. The analyses presented also provide quantitative evidence that shifts in the gasparticle partitioning of ambient organics with outdoor-to-indoor transport contribute significantly to variability in indoor
ambient organic carbon concentrations and suggest that methods to account for these shifts will further improve the
accuracy of outdoor-to-indoor transport models.
Hodas, N., Q. Meng, M. M. Lunden, & B. J. Turpin (2014) Toward refined estimates of ambient PM2.5 exposure: Evaluation of a
physical outdoor-to-indoor transport model, ATMOSPHERIC ENVIRONMENT 83:229-236.
Acute effects of black carbon and PM2.5 on children asthma admissions: A time-series study in a Chinese
city
Abstract - Epidemiologic evidence for an association between black carbon (BC) and health outcomes is limited. We
estimated associations and exposure–response relationships between childhood asthma admission and concentration of BC
and PM2.5 (particle less than 2.5 mm in aerodynamic diameter) in ambient air in Shanghai using a lag distributed model. The
PM2.5 and the BC were significantly associated with childhood asthma admissions in single-pollution model. However, the
effects of BC on asthma attacks were slightly stronger than those of PM 2.5 after adjusting or not adjusting for NO2 and SO2.
In conclusion, our study suggests combustion-associated particles are important in China. Black carbon should be considered
as one of the air quality indicators in China.
Hua, J., Y. Yin, L. Peng, L. Du, F. Geng, & L. Zhu (2014) Acute effects of black carbon and PM2.5 on children asthma admissions: A
time-series study in a Chinese city, SCIENCE OF THE TOTAL ENVIRONMENT 481:433-438.
Association of short-term increases in ambient air pollution and timing of initial asthma diagnosis among
medicaid-enrolled children in a metropolitan area
Abstract – Objective: We investigated associations of short-term changes in ambient ozone (O3), fine particulate matter
(PM2.5) and nitrogen dioxide (NO2) concentrations and the timing of new-onset asthma, using a large, high-risk population in
an area with historically high ozone levels. Methods: The study population included 18,289 incident asthma cases identified
among Medicaid-enrolled children in Harris County Texas between 2005–2007, using Medicaid Analytic Extract enrollment
and claims files. We used a time-stratified case-crossover design and conditional logistic regression to assess the effect of
increased short-term pollutant concentrations on the timing of asthma onset. Results: Each 10 ppb increase in ozone was
significantly associated with new-onset asthma during the warm season (May–October), with the strongest association seen
when a 6-day cumulative average period was used as the exposure metric (odds ratio [OR]=1.05, 95% confidence interval
[CI], 1.02–1.08). Similar results were seen for NO2 and PM2.5 (OR=1.07, 95% CI, 1.03–1.11 and OR=1.12, 95% CI, 1.03–
1.22, respectively), and PM2.5 also had significant effects in the cold season (November–April), 5-day cumulative lag
(OR=1.11. 95% CI, 1.00–1.22). Significantly increased ORs for O3 and NO2 during the warm season persisted in copollutant models including PM2.5. Race and age at diagnosis modified associations between ozone and onset of asthma.
Conclusion: Our results indicate that among children in this low-income urban population who developed asthma, their
initial date of diagnosis was more likely to occur following periods of higher short-term ambient pollutant levels.
Wendt, J. K., E. Symanski, T. H. Stock, W. Chan, & X. L. Du, (2014) Association of short-term increases in ambient air pollution and
timing of initial asthma diagnosis among medicaid-enrolled children in a metropolitan area, ENVIRONMENTAL RESEARCH 131:50-58.
Characteristics of indoor air pollution in rural mountainous and rural coastal communities in Indonesia
Abstract - The increased use of biomass fuel use among rural Indonesian households for years despite national program on
subsidized LPG fuel distribution pose threat of indoor air pollution for the householders. Indoor air pollution levels of PM2.5
and CO in the kitchen of 40 households using the fuelwood as the main cooking fuel were measured in the same season in
mountainous and coastal areas in Indonesia. The temporal variations of PM2.5 and its size distributions were simultaneously
measured using photoelectric UCB monitor and personal cascade impactor, respectively. While carbon monoxide (CO)
concentrations were measured using USB-CO monitors. Household indoor air pollution in the mountainous area was
generally higher than that in the coastal area. This is because the households in coastal area have higher kitchen volume
(about three times), smaller ventilation area (about 1.7 times) and shorter cooking duration with wood fuel (0.6 times) than
those in mountainous area. Yet, during cooking with fuelwood, the indoor PM2.5 concentrations at the cook site showed
almost comparable results for both sites. The wood stove burning in coastal area tended to be in flaming combustion than in
mountainous area. This can be indicated by a higher fraction of finest particles in PM2.5, a higher fraction of EC in PM2.5 and
a higher fraction of K+ and Cl− ions in PM2.5 mass concentrations. The time-averaged CO concentrations for 22-h
measurements at the mountainous area were higher than those in coastal area. The mountainous area showed higher positive
correlation relationship between the measured concentrations of CO and PM2.5 than those in the coastal area. The use of
cleaner fuel, e.g., subsidized LPG fuel in rural area should be promoted and managed intensively in mountainous area than in
coastal area to avoid people exposure of health damaging indoor air pollutants.
Huboyo, H. S., S. Tohno, P. Lestari, A. Mizohata, & M. Okumura (2014) Characteristics of indoor air pollution in rural mountainous
and rural coastal communities in Indonesia, ATMOSPHERIC ENVIRONMENT 82:343-350.
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AGRICULTURE
Climate change mitigation through livestock system transitions
Abstract - Livestock are responsible for 12% of anthropogenic greenhouse gas emissions. Sustainable intensification of
livestock production systems might become a key climate mitigation technology. However, livestock production systems
vary substantially, making the implementation of climate mitigation policies a formidable challenge. Here, we provide results
from an economic model using a detailed and high-resolution representation of livestock production systems. We project
that by 2030 autonomous transitions toward more efficient systems would decrease emissions by 736 million metric tons of
carbon dioxide equivalent per year (MtCO2e⋅y−1), mainly through avoided emissions from the conversion of 162 Mha of
natural land. A moderate mitigation policy targeting emissions from both the agricultural and land-use change sectors with a
carbon price of US$10 per tCO2e could lead to an abatement of 3,223 MtCO2e⋅y−1. Livestock system transitions would
contribute 21% of the total abatement, intra- and interregional relocation of livestock production another 40%, and all other
mechanisms would add 39%. A comparable abatement of 3,068 MtCO2e⋅y−1 could be achieved also with a policy targeting
only emissions from land-use change. Stringent climate policies might lead to reductions in food availability of up to 200 kcal
per capita per day globally. We find that mitigation policies targeting emissions from land-use change are 5 to 10 times more
efficient—measured in “total abatement calorie cost”—than policies targeting emissions from livestock only. Thus, fostering
transitions toward more productive livestock production systems in combination with climate policies targeting the land-use
change appears to be the most efficient lever to deliver desirable climate and food availability outcomes.
Havlík, P., H. Valin, M. Herrero, M. Obersteiner, E. Schmid, M. C. Rufino, A. Mosnier, P. K. Thornton, H. Böttcher, R. T.
Conant, S. Frank, S. Fritz, S. Fuss, F. Kraxner, & A. Notenbaert (2014) Climate change mitigation through livestock system transitions,
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA (early edition).
Agriculture: Steps to sustainable livestock
Summary - The need for efficient food production has never been greater. One in seven humans is undernourished1.
Urbanization and biofuel production are reducing land availability, and climate change, lack of water and soil degradation are
decreasing harvests. Over the past decade, cereal yields per hectare have fallen in one-quarter of countries. Meanwhile,
developing nations and the growing world population are demanding more animal protein…. Adopt smart supplements.
The productivity of ruminant animals can often be boosted with supplements, some of which encourage microbes in the
rumen to grow quickly and to provide better nutrition. In India, a water fern (Azolla caroliniana) cultivated in local ponds
provides extra protein to cattle and goats fed on protein-deficient elephant grass (Pennisetum purpureum). Other plant
extracts can alter the rumen microbial population to use nitrogen and energy more efficiently. This means producing more
meat and milk with proportionally less by-product greenhouse gas and ammonia. An enzyme in red clover (Trifolium
pratense), widely grown in temperate countries, increases ruminants' ability to utilize dietary protein. In field trials, dairy cows
with more clover in their diets ate more feed and produced more milk. In Australia, sheep nibble on the deep-rooted
perennial tar bush (Eremophila glabra) during dry autumns when most other pasture plants offer poor food value. Tar bush
combats gastrointestinal nematodes and acidosis, and reduces emissions of methane, a greenhouse gas 25 times more potent
than carbon dioxide…. There will be no one-size-fits-all solutions. Changing farming practices is difficult, but farm
platforms can evaluate potential for increased profits and other benefits, act as examples to follow, and provide information
for policy-makers. We hope to identify better practices to optimize the use of livestock in different regions, using local
resources, breeds and feedstuffs — and produce tangible evidence to convince local farmers.
Eisler, M. C., M. R. F. Lee, J. F. Tarlton, G. B. Martin, J. Beddington, J. A. J. Dungait, H. Greathead, J. Liu, S. Mathew, H.
Miller, T. Misselbrook, P. Murray, V. K. Vinod, R. Van Saun, & M. Winter (2014) Agriculture: Steps to sustainable livestock,
NATURE 507(7490):32-34.
Stable carbon isotopes of methane for real-time process monitoring in anaerobic digesters
Abstract - Efficient operation and stability of biogas plants requires continuous monitoring of the digester content.
Traditional laboratory analysis of digester sludge is often complex and time-consuming and shows a delayed response to
disruptions within the fermentation process. As a new approach, we applied an online measurement technique (laser
absorption spectroscopy) for real-time monitoring of stable carbon isotopes of methane in a pilot-scale biogas digester (3500
L) regularly fed with maize silage. Generally, isotopic composition of methane gives information about specific substrate
degradation, that is, methanogenic pathways that reflect the actual digester state. First results of a 2-wk monitoring
experiment show that stable carbon isotopes of methane respond promptly and highly dynamic to changes in the process
state of the digester. In combination with other monitoring parameters (methane production rate, concentration of volatile
fatty acids, and pH) the fluctuations in can be interpreted as a change in methanogenic pathways due to a high organic
loading rate. In this context, might be used as a new parameter tool for monitoring and characterization of the process state
of the digester.
Polag, D., L. C. Krapf, H. Heuwinkel, S. Laukenmann, J. Lelieveld, & F. Keppler (2014) Stable carbon isotopes of methane for realtime process monitoring in anaerobic digesters, ENGINEERING IN LIFE SCIENCES 14(2):153-160.
Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation
Abstract - Effect of cashew nut shell liquid (CNSL), a methane inhibitor, on bovine rumen fermentation was investigated
through analysis of the metabolic hydrogen flow estimated from concentrations of short-chain fatty acids (SCFA) and
methane. Three cows were fed a concentrate and hay diet without or with a CNSL-containing pellet. Two trials were
conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Methane production
was measured in a respiration chamber system, and energy balance and nutrient digestibility were monitored. The estimated
flow of metabolic hydrogen demonstrated that a part of metabolic hydrogen was used for hydrogen gas production, and a
large amount of it flowed into production of methane and SCFA in both trial 1 and 2, when CNSL was administered to the
bovine rumen. The results obtained by regression analyses showed that the effect of CNSL supply on methane reduction was
coupled with a significant (P < 0.01) decrease of acetate and a significant (P < 0.01) increase of propionate and hydrogen gas.
These findings reveal that CNSL is able to reduce methane and acetate production, and to increase hydrogen gas and
propionate production in vivo.
Mitsumori, M., O. Enishi, T. Shinkai, K. Higuchi, Y. Kobayashi, A. Takenaka, K. Nagashima, M. Mochizuki, & Y.
Kobayashi (2014) Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation, ANIMAL SCIENCE JOURNAL
85(3):227-232.
In vitro screening of selected feed additives, plant essential oils and plant extracts for rumen methane
mitigation
Abstract – BACKGROUND Ruminants produce large quantities of methane in their rumen as a by-product of microbial
digestion of feed. Antibiotics are added to ruminant feed to reduce wasteful production of methane; however, this practice
has some downsides. A search for safer and natural feed additives with anti-methanogenic properties is under way. The
objective of this research was to examine selected feed additives, plant essential oils and plant extracts for their antimethanogenic potential in the rumen using an in vitro batch fermentation system. RESULTS A significant reduction
(P < 0.05) in methane production was observed with nine feed additives (up to 40% reduction), all eight essential oils (up to
75% reduction) and two plant extracts (14% reduction) when compared to their respective controls. Amongst these, only an
algal meal high in docosahexaenoic acid, preparations of Nannochloropsis oculata, calcareous marine algae, yeast metabolites and
two tannins did not inhibit microbial gas and volatile acid production. CONCLUSIONS The current study identified some
potent dietary ingredients or plant compounds that can assist in developing novel feed additives for methane mitigation from
the rumen.
Durmic, Z., P. J Moate, R. Eckard, D. K Revell, R. Williams, & P. E Vercoe (2014) In vitro screening of selected feed additives, plant
essential oils and plant extracts for rumen methane mitigation, JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 94(6):11911196.
Effect of SRI Water Management On Water Quality and Greenhouse Gas Emissions in Korea
Abstract - A feasibility study on the system of rice intensification (SRI) methods with respect to irrigation requirements,
non-point source (NPS) pollution discharge, greenhouse gas (GHG) emissions and rice yields was conducted for either 2 or
3 years depending on the treatment in Korea. Large-size runoff plots were prepared, and the necessary measuring systems
installed. The SRI methods were carried out with a Japonica variety of rice, Odaebyeo (Oryza sativa L.), and the results were
compared with those for control plots. The data indicated the high potentiality of adoption of the SRI methods for paddy
farming in Korea. The SRI methods (i.e. SRI and conventional practice with SRI water management (CS)) reduced the
irrigation requirement by 50.2 and 46.0%, respectively. For the SRI and CS plots, averaged concentration reductions of
typical NPS pollutants, relative to conventional practice (CT) plots, ranged between 15.3 and 42.6%. The GHG emissions
from the conventional practice with two forced drainages (CD) and the CS plots, in terms of their CO2 equivalents, were
reduced by 65.5 and 72.8%, respectively, compared with those from the CT plots. The rice yields from the SRI and the CS
plots were not greater than those from the CT plots. Application of SRI water management methods could help to improve
Korea's water resources and water quality management, and could thus contribute to mitigation of the negative effects of
global warming.
Choi, J., G. Kim, W. Park, M. Shin, Y. Choi, S. Lee, S. Kim, & D. Yun (2014) Effect of SRI Water Management On Water Quality
and Greenhouse Gas Emissions in Korea, IRRIGATION AND DRAINAGE (Early View).
Methane production and methanogenic archaeal communities in two types of paddy soil amended with
different amounts of rice straw
Abstract - Soil type and returning straw to the field are the important factors that regulate CH4 formation in paddy soil, and
the variations of biogeochemical parameters and methanogens communities play important roles in the formation of CH4. In
the present study, two paddy soil types [silt loam soil (JX) and silty clay loam soil (GD)] with different amounts of rice straw
additions were incubated under anaerobic conditions to investigate the relationship between CH4 production,
biogeochemical variations, and methanogenic archaeal communities. Straw incorporation significantly stimulated
CH4 production in two soil types. CH4 production in JX soil was higher than the GD soil with equal straw addition.
Significant differences between biogeochemical parameters and methanogenic archaeal communities were observed between
two soil types. Straw addition increased archaeal 16S rRNA genes and mcrA genes copy numbers, especially in JX soil.
Multiple regression analysis indicated that variations in H2, sulfate, Fe (II) concentrations, archaeal 16S rRNA genes and mcrA
genes copy numbers, methanogens diversity index, and the relative abundance of Methanosarcinaceae and
Methanobacteriaceae together influenced CH4 production in two soil types. These results indicated that methane production
was influenced by the comprehensive effects of biotic and abiotic factors in paddy soils.
Bao, Q., K. Xiao, Z. Chen, H. Yao, & Y. Zhu (2014) Methane production and methanogenic archaeal communities in two types of paddy
soil amended with different amounts of rice straw, FEMS MICROBIOLOGY ECOLOGY (Early View).
Effects of no-till duration on the methane oxidation capacity of Alfisols
Abstract - Frequent tillage negatively affects the methane (CH4) oxidation capacity of agricultural soils. The restoration of
that capacity of soils through no-tillage (NT) adoption has been suggested, but is not well documented. With the expectation
of increased CH4 oxidation with longer NT duration, a tillage chronosequence study was conducted at paired sites in Ohio
under conventional tillage (or plow till, PT) and NT for 9, 13, 36, and 48 years. Nearby deciduous forests were also included
to estimate the maximum oxidation capacity of undisturbed local soils. Surface soil samples (0–5, 5–10, 10–20, 20–30 cm)
were collected in April (soil moisture 29 %) and in August 2010 (moisture 19 %), sieved (6.3 mm), and incubated (initial CH 4
5 μl L−1) to determine the CH4 oxidation capacity. The results showed a significant effect of tillage practice on CH4 oxidation.
With the exception of the site under NT for 9 years, the CH4 oxidation rates were consistently higher (2–40 times) in NT
than in PT soils during both the April and August sampling dates. A similar effect of NT was also observed when incubation
was conducted with intact soil cores, but the rates were lower, perhaps due to restriction of CH 4 diffusion in the cores.
Across the sampling dates and depth, the CH4 oxidation capacity increased linearly with NT duration averaging 3.2, 4.2, 11.5,
and 13.6 μg CH4-C kg−1 soil day−1 at sites under NT for 9, 13, 36, and 48 years, respectively. While the CH4 oxidation rate in
PT soil was 10–12 % of the level in the forest soils, it was 36–37% at sites under NT for >30 years. These results
demonstrate the positive effect of NT on the CH4 oxidation in soils and the potential impact of continued NT maintenance
on the CH4 sink strength of agricultural soils.
Jacinthe, P., W. A. Dick, R. Lal, R. K. Shrestha, & S. Bilen (2014) Effects of no-till duration on the methane oxidation capacity of
Alfisols, BIOL. FERTIL. SOILS. 50:477-486.
A simplified method for the design and sizing of anaerobic digestion systems for smaller farms
Abstract - Anaerobic digestion (AD) as a waste treatment practice has existed for nearly 200 years and has become an
accepted option for many farming and small-scale residential operations. Many developing countries now encourage the use
of AD in order to meet new environmental regulations and/or to provide small amounts of energy resulting from methane
generated during the process. This development has been met with some difficulty due to the lack of resources and
knowledge of the systems in many of the rural communities in which these digesters are placed. A properly designed AD
system can help prevent soil and water pollution as well as help mitigate methane emissions by capturing them for use as a
potential energy source. This paper focuses on providing guidance to the proper design and sizing of an AD system for
typical small farms, which account for the majority of dairy farms worldwide. A focus was on the implementation of such
systems as they might be applied in Central America, although the aspects studied here can be applied for AD systems
handling animal waste streams practically anywhere. We provide a method for sizing of anaerobic digester systems based on
design standards from the US National Resource Conservation Service and using field sampled data of holding pen wash
water runoff. An overview of the decision process for alternative designs is given, and simple-to-use nomographs are
presented for use in sizing of an anaerobic digester system for smaller (non-industrial)-scale farms.
Grant, W. D, & T. M. Lawrence (2014) A simplified method for the design and sizing of anaerobic digestion systems for smaller farms,
ENVIRON. DEV SUSTAIN. 16:345-360.
Abundance of Methanogens, Methanotrophic Bacteria, and Denitrifiers in Rice Paddy Soils
Abstract - Many studies have examined greenhouse gas fluxes from rice paddies, but information about microorganisms
involved in the process is limited. In this study, we used a molecular approach to identify functional genes including mcrA,
pmoA, and nirK/nirS/nosZ to quantify the abundance of methanogens, methane-oxidizing bacteria, and denitrifiers,
respectively. We also analyzed soil chemical properties such as soil organic matter, pH, and inorganic nitrogen to detect key
variables, which control the abundances of these microbes. Abundances of methanogens, methane-oxidizing bacteria, and
denitrifying genes were unchanged during the 1-year study. The abundances of methane-oxidizing bacteria and denitrifiers,
except for methanogens, were highest near the soil surface where oxygen availability was likely higher. It is noteworthy that
genes for the reduction of CH4 and N2O were particularly abundant near the soil surface. Additionally, most of gene
abundances were correlated with SOM and inorganic nitrogen especially during summer. Overall, the results indicated that
microbes responsible for CH4 or N2O dynamics were not affected by seasons, but were sensitive to oxygen availability and
soil chemical properties. We also concluded that GHG emission would be stimulated by increased C availability and
microbial activities in rice paddies, which are expected to be enhanced by global climate change.
Seo, J., I. Jang, G. Gebauer, & H. Kang (2014) Abundance of Methanogens, Methanotrophic Bacteria, and Denitrifiers in Rice Paddy
Soils, WETLANDS 34(2):213-223.
Microbial community structure of a pilot-scale thermophilic anaerobic digester treating poultry litter
Abstract - The microbial community structure of a stable pilot-scale thermophilic continuous stirred tank reactor digester
stabilized on poultry litter was investigated. This 40-m3 digester produced biogas with 57 % methane, and chemical oxygen
demand removal of 54 %. Bacterial and archaeal diversity were examined using both cloning and pyrosequencing that
targeted 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes, constituting 93 % of the clones and
76 % of the pyrotags. Of the Firmicutes, class Clostridia (52 % pyrotags) was most abundant followed by class Bacilli (13 %
pyrotags). The bacterial libraries identified 94 operational taxonomic units (OTUs) and pyrosequencing identified 577 OTUs
at the 97 % minimum similarity level. Fifteen OTUs were dominant (≥2 % abundance), and nine of these were novel
unclassified Firmicutes. Several of the dominant OTUs could not be classified more specifically than Clostridiales, but were
most similar to plant biomass degraders, including Clostridium thermocellum. Of the rare pyrotag OTUs (<0.5 % abundance),
75 % were Firmicutes. The dominant methanogen was Methanothermobacter which has hydrogenotrophic metabolism, and
accounted for >99 % of the archaeal clones. Based on the primary methanogen, as well as digester chemistry (high VA and
ammonia levels), we propose that bacterial acetate oxidation is the primary pathway in this digester for the control of acetate
levels.
Smith, A. M., D. Sharma, H. Lappin-Scott, S. Burton, & D. H. Huber (2014) Microbial community structure of a pilot-scale
thermophilic anaerobic digester treating poultry litter, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 98(5):2321-2334 (2014).
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BIOMASS BURNING & COOKING AND HEATING
How many replicate tests are needed to test cookstove performance and emissions? — Three is not always
adequate
Abstract - Almost half of the world's population still cooks on biomass cookstoves of poor efficiency and primitive design,
such as three stone fires (TSF). Emissions from biomass cookstoves contribute to adverse health effects and climate change.
A number of improved cookstoves with higher energy efficiency and lower emissions have been designed and promoted
across the world. During the design development, and for the selection of a stove for dissemination, the stove performance
and emissions are commonly evaluated, communicated and compared using the arithmetic average of replicate tests made
using a standardized laboratory-based test, commonly the water boiling test (WBT). However, the statistics section of the
test protocol contains some debatable concepts and in certain cases, easily misinterpreted recommendations. Also, there is
no agreement in the literature on how many replicate tests should be performed to ensure “confidence” in the reported
average performance (with three being the most common number of replicates). This matter has not received sufficient
attention in the rapidly growing literature on stoves, and yet is crucial for estimating and communicating the performance of
a stove, and for comparing the performance between stoves. We illustrate an application using data from a number of
replicate tests of performance and emission of the Berkeley–Darfur Stove (BDS) and the TSF under well-controlled
laboratory conditions. Here we focus on two as illustrative: time-to-boil and emissions of PM2.5 (particulate matter less than
or equal to 2.5 μm in diameter). We demonstrate that an interpretation of the results comparing these stoves could be
misleading if only a small number of replicates had been conducted. We then describe a practical approach, useful to both
stove testers and designers, to assess the number of replicates needed to obtain useful data from previously untested stoves
with unknown variability.
Wang, Y., M. D. Sohn, Y. Wang, K. M. Lask, T. W. Kirchstetter, & A. J. Gadgil (2014) How many replicate tests are needed to test
cookstove performance and emissions? — Three is not always adequate, ENERGY FOR SUSTAINABLE DEVELOPMENT 20:21-29.
Wildland fire emissions, carbon, and climate: Emission factors
Abstract - While the vast majority of carbon emitted by wildland fires is released as CO2, CO, and CH4, wildland fire smoke
is nonetheless a rich and complex mixture of gases and aerosols. Primary emissions include significant amounts of CH 4 and
aerosol (organic aerosol and black carbon), which are short-lived climate forcers. In addition to CO2 and short-lived climate
forcers, wildland fires release CO, non-methane organic compounds (NMOC), nitrogen oxides (NOx = NO + NO2), NH3,
and SO2. These species play a role in radiative forcing through their photochemical processing, which impacts atmospheric
levels of CO2, CH4, tropospheric O3, and aerosol. This paper reviews the current state of knowledge regarding the chemical
composition of emissions and emission factors for fires in United States vegetation types as pertinent to radiative forcing and
climate. Emission factors are critical input for the models used to estimate wildland fire greenhouse gas and aerosol emission
inventories.
Urbanski, S. (2014) Wildland fire emissions, carbon, and climate: Emission factors, FOREST ECOLOGY AND MANAGEMENT 317:5160.
Influence of open vegetation fires on black carbon and ozone variability in the southern Himalayas (NCOP, 5079 m a.s.l.)
Abstract - We analysed the variability of equivalent black carbon (BC) and ozone (O3) at the global WMO/GAW station
Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.) in the southern Himalayas, for evaluating the possible
contribution of open vegetation fires to the variability of these short-lived climate forcers/pollutants (SLCF/SLCP) in the
Himalayan region. We found that 162 days (9% of the data-set) were characterised by acute pollution events with enhanced
BC and O3 in respect to the climatological values. By using satellite observations (MODIS fire products and the USGS Land
Use Cover Characterization) and air mass back-trajectories, we deduced that 56% of these events were likely to be affected
by emissions from open fires along the Himalayas foothills, the Indian Subcontinent and the Northern Indo-Gangetic Plain.
These results suggest that open fire emissions are likely to play an important role in modulating seasonal and inter-annual BC
and O3 variability over south Himalayas.
Putero, D., T.C. Landi, P. Cristofanelli, A. Marinoni, P. Laj, R. Duchi, F. Calzolari, G.P. Verza, & P. Bonasoni, Influence of
open vegetation fires on black carbon and ozone variability in the southern Himalayas (NCO-P, 5079 m a.s.l.), ENVIRONMENTAL
POLLUTION 184:597-604 (2014).
Indoor air pollution in slum neighbourhoods of Addis Ababa, Ethiopia
Abstract - An estimated 95% of the population of Ethiopia uses traditional biomass fuels, such as wood, dung, charcoal, or
crop residues, to meet household energy needs. As a result of the harmful smoke emitted from the combustion of biomass
fuels, indoor air pollution is responsible for more than 50,000 deaths annually and causes nearly 5% of the burden of disease
in Ethiopia. Very limited research on indoor air pollution and its health impacts exists in Ethiopia. This study was, therefore,
undertaken to assess the magnitude of indoor air pollution from household fuel use in Addis Ababa, the capital city of
Ethiopia. During January and February, 2012, the concentration of fine particulate matter (PM 2.5) in 59 households was
measured using the University of California at Berkeley Particle Monitor (UCB PM). The raw data was analysed using
Statistical Package of Social Science (SPSS version 20.0) software to determine variance between groups and descriptive
statistics. The geometric mean of 24-h indoor PM2.5 concentration is approximately 818 μg m−3 (Standard deviation
(SD = 3.61)). The highest 24-h geometric mean of PM2.5 concentration observed were 1134 μg m−3 (SD = 3.36), 637 μg m−3
(SD = 4.44), and 335 μg m−3 (SD = 2.51), respectively, in households using predominantly solid fuel, kerosene, and clean
fuel. Although 24-h mean PM2.5 concentration between fuel types differed statistically (P < 0.05), post hoc pairwise
comparison indicated no significant difference in mean concentration of PM2.5 between improved biomass stoves and
traditional stoves (P > 0.05). The study revealed indoor air pollution is a major environmental and health hazard from home
using biomass fuel in Addis Ababa. The use of clean fuels and efficient cooking stoves is recommended.
Sanbata, H., A. Asfaw, & A. Kumie (2014) Indoor air pollution in slum neighbourhoods of Addis Ababa, Ethiopia, ATMOSPHERIC
ENVIRONMENT 89:230-234.
Impact of operating wood-burning fireplace ovens on indoor air quality
Abstract - The use of combustion heat sources like wood-burning fireplaces has regained popularity in the past years due to
increasing energy costs. While the outdoor emissions from wood ovens are strictly regulated in Germany, the indoor release
of combustion products is rarely considered. Seven wood burning fireplaces were tested in private homes between
November 2012 and March 2013. The indoor air quality was monitored before, during and after operation. The following
parameters were measured: ultra-fine particles (5.6–560 nm), fine particles (0.3–20 μm), PM2.5, NOx, CO, CO2,
formaldehyde, acetaldehyde, volatile organic compounds (VOCs) and benzo[a]pyrene (BaP). Most ovens were significant
sources of particulate matter. In some cases, an increase of benzene and BaP concentrations was observed in the indoor air.
The results illustrate that wood-burning fireplaces are potential sources of indoor air contaminants, especially ultra-fine
particles. Under the aspect of lowering indoor air exchange rates and increasing the use of fuels with a net zero-carbon
footprint, indoor combustion sources are an important topic for the future. With regards to consumer safety, product
development and inspection should consider indoor air quality in addition to the present fire protection requirements.
Salthammer, T., T. Schripp, S. Wientzek, & M. Wensing (2014) Impact of operating wood-burning fireplace ovens on indoor air quality,
CHEMOSPHERE 103:205-211.
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WASTE
Greenhouse Gas Emission and Energy Consumption in Wastewater Treatment Plants: Impact of
Operating Parameters
Abstract - Greenhouse gas (GHG) emission and energy consumption were estimated in wastewater treatment plants using
an elaborate mathematical model that included coagulation/flocculation, anaerobic digester, nitrification/denitrification, and
biogas recovery. The examined treatment systems used aerobic, anaerobic, and hybrid biological processes. The impact of
pertinent operating parameters including reactor temperature, solid retention time (SRT), primary clarifier underflow rate,
and biochemical oxygen demand concentration on GHG emission and energy consumption were investigated, leading to the
identification of controlling operating parameters and adequate strategies to reduce GHG emission and energy consumption.
The overall GHG emission was 3152, 6051, and 6541 kg CO2-equivalent/day, while the estimated energy consumption
amounted to 4028, 2017, and 3084 MJ/day in the three examined systems, respectively. Parametric studies showed that the
best strategy to reduce GHG emission and energy consumption would result from 12% increase in the bioreactor
temperature in the aerobic system, 10% increase of the bioreactor temperature and five days increase of SRT in the
anaerobic system, and 10% increase of temperature and five days reduction of SRT in the anaerobic bioreactor of the hybrid
system. Additional reductions in the GHG emission and energy consumption would result from 50% increase of the primary
clarifier underflow rate.
Ashrafi, O., L. Yerushalmi, & F. Haghighat (2014) Greenhouse Gas Emission and Energy Consumption in Wastewater Treatment
Plants: Impact of Operating Parameters, CLEAN – SOIL, AIR, WATER 42(3):207-220.
Optimal landfill gas utilization for renewable energy production
Abstract – Landfill gas (LFG) is essentially greenhouse gas (GHG) composed predominantly of methane and carbon
dioxide produced from the anaerobic biodegradation of municipal solid waste in landfills. The amount of gas produced can
be estimated using the Intergovernmental Panel on Climate Change methodology. Most sanitary landfills flare this potential
renewable energy source, which is an unfortunate waste of a valuable resource. This study develops an optimization model
for effective LFG utilization as a sustainable energy source based on economic and environmental considerations. The mixed
integer linear programming model developed was applied to Seelong Sanitary Landfill, Malaysia, and led to profits 7.6 times
higher than those currently gained. This enormous increase is due to the incorporation of renewable energy production in
the new plan. In addition, the combined heat and power generation proposed is 2420 tons of oil equivalents, which is
0.0035% of the total energy production of Malaysia. Similarly, the LFG utilization leads to a national GHG reduction of
0.007%. Implementing this at the 14 sanitary landfills in the country will go a long way towards broadening the energy base
while simultaneously reducing the carbon footprint of the nation.
Isa, A. S., A. Johari, H. Hashim, R. Mat, J. S. Lim, N. Ngadi, & A. Ali (2014) Optimal landfill gas utilization for renewable energy
production, ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY (Early View).
Prediction of methane production in wastewater treatment facility: a data-mining approach
Abstract - A prediction model for methane production in a wastewater processing facility is presented. The model is built by
data-mining algorithms based on industrial data collected on a daily basis. Because of many parameters available in this
research, a subset of parameters is selected using importance analysis. Prediction results of methane production are presented
in this paper. The model performance by different algorithms is measured with five metrics. Based on these metrics, a model
built by the Adaptive Neuro-Fuzzy Inference System algorithm has provided most accurate predictions of methane
production.
Kusiak, A., & X. Wei (2014) Prediction of methane production in wastewater treatment facility: a data-mining approach, ANN. OPER. RES.
216:71-81.
Improving the Energy Balance of an Integrated Microalgal Wastewater Treatment Process
Abstract - The inclusion of a microalgal system in a wastewater treatment flowsheet for residual nutrient uptake can be
justified by processing the waste biomass for energy recovery. Low energy harvesting technologies and pre-treatment of the
algal biomass are required to improve the overall energy balance of this integrated system. Scenedesmus obliquus and Chlorella
sp., achieving nitrogen and phosphorus removal rates higher than 90 %, were used to compare cells recovery efficiency and
energy requirements of two energy efficient harvesting systems: dissolved air flotation (DAF) and ballasted dissolved air
flotation (BDAF). In addition, thermal hydrolysis was used as a pre-treatment to improve biogas production during
anaerobic digestion. The energy required for both systems was then considered to estimate the daily energy demand and
efficiency of two microalgae wastewater treatment plants with a capacity of 25,000 and 230,000 p.e., respectively. Overall, a
high algal cells recovery efficiency (99 %) was achieved using low energy demand (0.04 kWh m−3 for BDAF) and a coagulant
dose reduction between 42 and 50 % depending on the algal strain. Anaerobic digestion of pre-treated S. obliquus showed a
threefold increase in methane yield. Compared to a traditional activated sludge process, the additional tertiary microalgal
treatment generates an integrated process potentially able to achieve up to 76 % energy efficiency.
Ometto, F., R. Whitton, F. Coulon, B. Jefferson, & R. Villa (2014) Improving the Energy Balance of an Integrated Microalgal
Wastewater Treatment Process, WASTE AND BIOMASS VALORIZATION 5(2):245-253.
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FOSSIL FUELS
Application of in-seam directional drilling technology for gas drainage with benefits to gas outburst
control and greenhouse gas reductions in Daning coal mine, China
Abstract - Gas outburst disasters are becoming more serious as the underground coal mines become deeper in China, and a
thick zone of deformed coal provides conditions favorable to coal and gas outbursts. The Daning coal mine’s main mining
seam is the No. 3 coal seam with coal and gas outburst hazard, which often contains two normal coal sub-layers and one
deformed sub-layer. Considering both the geological conditions of the coal seam and applications of the in-seam directional
longhole drilling technology, a new schematic diagram of in-seam directional longholes for gas drainage is developed. The
two borehole layout models of longwall panel and main entries for gas outburst disasters control have been successfully
applied. The gas drainage rates of both models are >70 %, and the residual gas contents are both <8 m3/t, which can be
considered that the gas outburst disasters were effectively controlled. To better guide gas drainage, gas drainage normal and
failure modes have been obtained. Although in-seam directional longhole technology has been successfully applied for
regional gas drainage with benefits to gas outburst control, there are also some problems that are detrimental to greenhouse
gas reductions in gas drainage and gas utilization. The three main problems are air leakage failure in gas drainage, decreasing
gas concentration and a low gas utilization ratio. To address the problems mentioned above, five improvements are
suggested.
Lu, S., Y. Cheng, J. Ma, & Y. Zhang (2014) Application of in-seam directional drilling technology for gas drainage with benefits to gas
outburst control and greenhouse gas reductions in Daning coal mine, China, NATURAL HAZARDS.
Drilling into controversy: the educational complexity of shale gas development
Abstract - Potential development of shale gas presents a complicated and controversial education problem. Research on
human learning and our own experiences as educators support the conclusion that traditional, disciplinary-focused
educational experiences are insufficient due to the nature of the concepts necessary for understanding the development of
shale gas within the energy system as a complex, contextualized phenomenon. Educators engaging in communicating
complex phenomena such as shale gas development can also increase sophistication of learner understanding by taking into
account the sociocultural and psychological mechanisms that shape one’s understanding of the change processes at work.
We therefore review an emerging body of research showing that nurturing environmental literacy requires more than the
clear explication of evidence, and instead requires interrogating one’s existing worldview and comparing alternative options
for action, as opposed to analyzing energy options in isolation. We then apply the results of this research to the challenging
task of creating meaningful learning experiences and engagement with complex issues such as emerging energy systems and
shale gas development in particular.
Henderson, J. A., & D. Duggan-Haas (2014) Drilling into controversy: the educational complexity of shale gas development, JOURNAL OF
ENVIRONMENTAL STUDIES AND SCIENCES 4(1):87-96.
The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence
from a panel of developed countries
Abstract - The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas
emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide
emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35
developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975–2012. In
order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel
cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run
relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other
emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period.
Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the
intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce
emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on
human health and the environment.
Akhmat, G., K. Zaman, T. Shukui, .F. Sajjad, M. A. Khan, & M. Z. Khan (2014) The challenges of reducing greenhouse gas emissions
and air pollution through energy sources: evidence from a panel of developed countries, ENVIRON. SCI. POLLUT. RES.
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TRANSPORT
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.
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VULNERABLE REGIONS
Climate trends in the Arctic as observed from space
Abstract - The Arctic is a region in transformation. Warming in the region has been amplified, as expected from ice-albedo
feedback effects, with the rate of warming observed to be ∼0.60 ± 0.07°C/decade in the Arctic (>64°N) compared to
∼0.17°C/decade globally during the last three decades. This increase in surface temperature is manifested in all components
of the cryosphere. In particular, the sea ice extent has been declining at the rate of ∼3.8%/decade, whereas the perennial ice
(represented by summer ice minimum) is declining at a much greater rate of ∼11.5%/decade. Spring snow cover has also
been observed to be declining by −2.12%/decade for the period 1967–2012. The Greenland ice sheet has been losing mass
at the rate of ∼34.0 Gt/year (sea level equivalence of 0.09 mm/year) during the period from 1992 to 2011, but for the period
2002–2011, a higher rate of mass loss of ∼215 Gt/year has been observed. Also, the mass of glaciers worldwide declined at
the rate of 226 Gt/year from 1971 to 2009 and 275 Gt/year from 1993 to 2009. Increases in permafrost temperature have
also been measured in many parts of the Northern Hemisphere while a thickening of the active layer that overlies permafrost
and a thinning of seasonally frozen ground has also been reported. To gain insight into these changes, comparative analysis
with trends in clouds, albedo, and the Arctic Oscillation is also presented.
Comiso, J. C., & D. K. Hall (2014) Climate trends in the Arctic as observed from space, WILEY INTERDISCIPLINARY REVIEWS:
CLIMATE CHANGE (Early View).
Annual distributions and sources of Arctic aerosol components, aerosol optical depth, and aerosol
absorption
Abstract - Radiative forcing by aerosols and tropospheric ozone could play a significant role in recent Arctic warming.
These species are in general poorly accounted for in climate models. We use the GEOS-Chem global chemical transport
model to construct a 3-D representation of Arctic aerosols and ozone that is consistent with observations and can be used in
climate simulations. We focus on 2008, when extensive observations were made from different platforms as part of the
International Polar Year. Comparison to aircraft (ARCTAS), surface, and ship cruise (ICEALOT, ASCOS) observations
suggests that GEOS-Chem provides in general a successful year-round simulation of Arctic black carbon (BC), organic
carbon (OC), sulfate, and dust aerosol. BC has major fuel combustion and boreal fire sources, OC is mainly from fires,
sulfate has a mix of anthropogenic and natural sources, and dust is mostly from the Sahara. The model is successful in
simulating aerosol optical depth (AOD) observations from AERONET stations in the Arctic; the sharp drop from spring to
summer appears driven in part by the smaller size of sulfate aerosol in summer. The anthropogenic contribution to Arctic
AOD is a factor of 4 larger in spring than summer and is mainly sulfate. Simulation of absorbing aerosol optical depth
(AAOD) indicates that non-BC aerosol (OC and dust) contributed 24% of Arctic AAOD at 550 nm and 37% of absorbing
mass deposited to the snow pack in 2008. Open fires contributed half of AAOD at 550 nm and half of deposition to the
snowpack.
Breider, T. J., L. J. Mickley, D. J. Jacob, Q. Wang, J. A. Fisher, R. Y.-W. Chang, & B. Alexander (2014) Annual distributions and
sources of Arctic aerosol components, aerosol optical depth, and aerosol absorption, JOURNAL OF GEOPHYSICAL RESEARCH:
ATMOSPHERES (Accepted Article).
An AeroCom assessment of black carbon in Arctic snow and sea ice
Abstract - Though many global aerosols models prognose surface deposition, only a few models have been used to directly
simulate the radiative effect from black carbon (BC) deposition to snow and sea ice. Here, we apply aerosol deposition fields
from 25 models contributing to two phases of the Aerosol Comparisons between Observations and Models (AeroCom)
project to simulate and evaluate within-snow BC concentrations and radiative effect in the Arctic. We accomplish this by
driving the offline land and sea ice components of the Community Earth System Model with different deposition fields and
meteorological conditions from 2004 to 2009, during which an extensive field campaign of BC measurements in Arctic snow
occurred. We find that models generally underestimate BC concentrations in snow in northern Russia and Norway, while
overestimating BC amounts elsewhere in the Arctic. Although simulated BC distributions in snow are poorly correlated with
measurements, mean values are reasonable. The multi-model mean (range) bias in BC concentrations, sampled over the same
grid cells, snow depths, and months of measurements, are −4.4 (−13.2 to +10.7) ng g−1 for an earlier phase of Aero-Com
models (phase I), and +4.1 (−13.0 to +21.4) ng g−1 for a more recent phase of AeroCom models (phase II), compared to the
observational mean of 19.2 ng g−1. Factors determining model BC concentrations in Arctic snow include Arctic BC
emissions, transport of extra-Arctic aerosols, precipitation, deposition efficiency of aerosols within the Arctic, and meltwater
removal of particles in snow. Sensitivity studies show that the model–measurement evaluation is only weakly affected by
meltwater scavenging efficiency because most measurements were conducted in non-melting snow. The Arctic (60–90_ N)
atmospheric residence time for BC in phase II models ranges from 3.7 to 23.2 days, implying large inter-model variation in
local BC deposition efficiency. Combined with the fact that most Arctic BC deposition originates from extra-Arctic
emissions, these results suggest that aerosol removal processes are a leading source of variation in model performance. The
multi-model mean (full range) of Arctic radiative effect from BC in snow is 0.15 (0.07–0.25)Wm−2 and 0.18 (0.06–0.28)Wm−2
in phase I and phase II models, respectively. After correcting for model biases relative to observed BC concentrations in
different regions of the Arctic, we obtain a multi-model mean Arctic radiative effect of 0.17Wm−2 for the combined
AeroCom ensembles. Finally, there is a high correlation between modeled BC concentrations sampled over the observational
sites and the Arctic as a whole, indicating that the field campaign provided a reasonable sample of the Arctic.
Jiao, C., M. G. Flanner, Y. Balkanski, S. E. Bauer, N. Bellouin, T. K. Berntsen, H. Bian, K. S. Carslaw, M. Chin, N. De Luca,
T. Diehl, S. J. Ghan, T. Iversen, A. Kirkevåg, D. Koch, X. Liu, G. W. Mann, J. E. Penner, G. Pitari, M. Schulz, Ø. Seland, R.
B. Skeie, S. D. Steenrod, P. Stier, T. Takemura, K. Tsigaridis, T. van Noije, Y. Yun, & K. Zhang (2014) An AeroCom
assessment of black carbon in Arctic snow and sea ice, ATMOSPHERIC CHEMISTRY AND PHYSICS 14(5):2399-2417.
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CROSS CUTTING
New Directions: Support for integrated decision-making in air and climate policies - Development of a
metrics-based information portal
Abstract - Air pollution and climate change are inextricably linked (Jacob and Winner, 2009). However, they are normally
treated separately which can lead to incoherent strategies. An example is domestic biomass heating dubbed as a climate
friendly option, however, co-emitted air pollutants, such as black carbon, decrease air quality significantly (Williams, 2012).
To support integrated thinking on air and climate policies, that is taking into account co-benefits and avoiding of trade-offs,
currently available scientific information needs to be better linked and made available in a more comparable, comprehensive
and accessible format at various decision-making levels. Here we report on the plans to develop a framework that will be
strongly grounded in the science that would relate disconnected pieces of information for discussions between scientist and
policy makers targeted at maximizing co-benefits and avoiding trade-offs in relation to existing policy targets. This proposal
is the main outcome of a workshop held in October 2013, where about 30 scientific experts and policy makers invited by the
Institute for Advanced Sustainability Studies (IASS) and the European Environment Agency (EEA) discussed how the
scientific knowledge base on air-climate interactions can be best made available to policy makers and other stakeholders, as
well as the needs of decision-makers in this arena. Participants from Europe, Asia and the USA represented climate,
atmospheric, and health sciences, environmental agencies, national and regional policy makers, NGOs, and international
organizations.
Schmale, J., J. van Aardenne, E. von Schneidemesser (2014) New Directions: Support for integrated decision-making in air and climate
policies - Development of a metrics-based information portal, ATMOSPHERIC ENVIRONMENT (Accepted Manuscript).