Tuesday, October 21
8:00 AM – 9:15 AM
Ken Carslaw, PhD, Institute for Climate and Atmospheric Science and School of Earth& Environment, University of Leeds, United Kingdom
Aerosol science has made enormous steps in understanding fundamental processes and in making measurements that probe ever more complex particle properties. But how much of this new knowledge is being translated into better models of how aerosols affect climate? From the third to the fifth IPCC assessment report, aerosols have remained the largest radiative forcing uncertainty. In this presentation I address two questions: firstly, whether we are working on the right processes and secondly, how we can use models and observations to slowly reduce the persistent uncertainty. Using fairly well established statistical techniques it is possible to perform essentially a Monte Carlo simulation with a complex global aerosol model. This enables the contribution of all important processes to the overall prediction uncertainty to be quantified and mapped. The list of key processes turns out to differ substantially depending on whether you want to understand the uncertainty in present-day aerosol or its effect on radiative forcing. The properties of biomass burning particles are important for present-day global CCN uncertainty but are less important for the uncertainty in forcing, although big questions remain about how these particles interact with clouds. The list also depends on whether you want to understand the sources of uncertainty in forcing since the pre-industrial period or over recent decades. Natural aerosols tend to dominate forcing uncertainty when referenced back to the pre-industrial, but uncertain anthropogenic emissions are the most important factor for recent changes in forcing, with aerosol microphysical processes being less important. Regardless, the list of most uncertain parameters enables us to begin to constrain the model uncertainty using well-chosen measurements. In this direction, I will describe a methodology that could be used to define an optimum measurement strategy if the reduction in model uncertainty is the objective.
Ken Carslaw is a professor of atmospheric science at the University of Leeds in the UK. He is director of the Institute for Climate and Atmospheric Science and holder of the Royal Society Wolfson Award. Dr. Carslaw received his BSc in physics from the University of Birmingham, UK, and his PhD from the University of East Anglia in stratospheric aerosol thermodynamics. His early career at the Max Planck Institute for Chemistry in Mainz focused on understanding polar stratospheric clouds, leading to the discovery of liquid PSCs. Since 2005 his research group at Leeds has developed the Global Model of Aerosol Processes (GLOMAP). The model has been used to tackle a diverse range of aerosol problems, notably the role of nucleation in generating global CCN. Dr. Carslaw has published 130 papers on aerosol processes with diverse topics including nucleation, aerosol-cloud interaction, global CCN, Arctic and marine processes, volcanic impacts, Earth system couplings, stratospheric aerosol and model uncertainty. He is co-founding and now executive editor of Atmospheric Chemistry and Physics.
Wednesday, October 22
8:00 AM – 9:15 AM
Fine Particulate Air Pollution and Human Health: Science, Public Policy, and Controversy
C. Arden Pope III, PhD, Mary Lou Fulton Professor of Economics, Brigham Young University, Provo, UT
There is increasingly compelling scientific evidence that breathing fine particulate air pollution contributes to human morbidity and mortality. Epidemiologic evidence suggests that short-term exposure exacerbates existing pulmonary and cardiovascular disease and increases the risk of becoming symptomatic, requiring medical attention, or even dying. Long-term repeated exposures increase the risk of chronic pulmonary and cardiovascular disease. There appears to be multiple mechanistic pathways that link exposure with adverse health outcomes including, pulmonary/systemic oxidative stress and inflammation, enhanced initiation and progression of atherosclerosis, and altered cardiac autonomic function. A recent integrated study of factors that contribute to burden of disease suggest that exposure to fine particulate air pollution contributes substantially to global burden of disease, especially in much of the developing world. There is also evidence that public policy efforts to reduce fine particulate matter air pollution can be successful, can improve air quality, and can contribute to enhanced human health. Pollution abatement efforts, however, can also be costly, challenging and controversial. This presentation will focus on the air pollution health science that motivates the public policy and will briefly discuss the most recent controversy regarding the use of “secret science” to inform public policy.
Dr. C. Arden Pope III is the Mary Lou Fulton Professor of Economics at Brigham Young University. He received his PhD from Iowa State University (economics/statistics) and was a Fellow at the Harvard School of Public Health (environmental health and public policy). He has conducted research dealing with various natural resource and environmental issues. His cross-disciplinary research in environmental economics and air pollution epidemiology has resulted in seminal studies on the health effects and costs of air pollution. Dr. Pope has conducted or collaborated on various key studies of human health effects of short- and long-term air pollution exposure, has played prominent roles in reviewing and interpreting this literature, and is one of the world’s most widely cited and recognized experts on the health effects of air pollution. He has been the recipient of various honors and awards including the Thomas T. Mercer Joint Prize from the American Association for Aerosol Research and the International Society for Aerosols in Medicine (2001), the Utah Governor’s Medal for Science & Technology (2004), BYU’s Karl G. Maeser Distinguished Faculty Lecturer (2006); Honorary Fellow of the American College of Chest Physicians (FCCP Hon, 2008),and International Society for Environmental Epidemiology Best Environmental Epidemiology Paper Award (2010).
Thursday, October 23
8:00 AM – 9:15 AM
Allen L. Robinson, PhD, Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA
Emissions from motor vehicles, wildfires, and other combustion processes are major contributors to atmospheric fine particle mass. These emissions are a complex mixture of organic and inorganic species. Some of these species are directly emitted as particles, but the vast majority of the emissions are gases and vapors. Upon entering the atmosphere, emissions are exposed to oxidants and sunlight, which causes them to evolve chemically and physically, generating secondary particulate matter. To develop effective control strategies one must understand the overall contribution of emissions from combustion processes to ambient particulate matter -- both direct particle emissions and particle mass formed in the atmosphere. This talk will synthesize results from source testing, tunnel experiments, ambient measurements and chemical transport modeling to investigate the atmospheric evolution of emissions from combustion processes, focusing on organic aerosols. The results reveal a dynamic picture in which secondary organic aerosol formed in the atmosphere dramatically exceeds the direct particle emissions, especially for low emitting sources. Both speciation data and mass closure analysis indicate that low-volatility vapors are an important class of secondary organic aerosol precursors. The talk concludes with a brief discussion of the implications of these findings on human exposures, climate, and the design of regulations to control pollutant emissions.
Dr. Allen L. Robinson is the Raymond J. Lane Distinguished Professor and Head of the Department of Mechanical Engineering at Carnegie Mellon University. He is also a professor in the Department of Engineering and Public Policy and a member of the Center for Atmospheric Particle Studies. Dr. Robinson’s research examines the impact of emissions from energy systems on air quality and global climate. A major focus is the atmospheric transformation of particulate matter emissions from cars, trucks, and other combustion systems. In 2012-2013 he was a faculty member at Colorado State University in the Departments of Atmospheric Science and Mechanical Engineering. In 2009-2010, he was a visiting faculty fellow at the Cooperative Institute for Research in Environmental Science at the University of Colorado in Boulder. He is currently serving on the Research Committee of the Health Effects Institute, the Environmental Protection Agency Clean Air Scientific Advisory Committee (CASAC) Air Monitoring and Methods Subcommittee. He holds a BS in civil engineering from Stanford University and an MS and PhD in mechanical engineering from the University of California at Berkeley.
Friday, October 24
8:00 AM – 9:15 AM
Tami Bond, PhD, Civil and Environmental Engineering and University Scholar, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL
Over the last 25 years, the climate research community has acknowledged that direct and cloud-related aerosol radiative forcing is one of the greatest uncertainties in understanding the trajectory of future climate. Understanding of present-day and historical aerosol forcing assists in determining climate sensitivity. Dr. Bond will discuss what is known about the historical evolution of burning biofuel to provide energy, the characteristics of emitted particles, and how these particles change with combustion technology. She will review how emission measurements made in controlled situations differ from those in real, in-use settings. She will also look forward to changes expected during the next 25 years, when aerosol concentrations will decrease or remain the same. The growing greenhouse-gas forcing is quite likely to overwhelm aerosol forcing, leaving aerosol science as a less important player in the climate arena. Nevertheless, stresses on well-being via climate and health are likely to persist, increasingly concentrated among sensitive and low-income populations. Dr. Bond argues that aerosol scientists will have a transformed but equally relevant role to play in the coming world.
Tami Bond is an associate professor in civil and environmental engineering and University Scholar at the University of Illinois at Urbana-Champaign. Her research group measures aerosol properties in the laboratory and emission rates far afield, and uses modeling to explore particle properties and their climate impact. She has BS and MS degrees in mechanical engineering, and an interdisciplinary PhD from the University of Washington. She was a NOAA Climate and Global Change Postdoctoral Researcher, received an NSF CAREER award, has been an editor of Aerosol Science & Technology, and currently serves on the U.S. Technical Advisory Group to the ISO Technical Committee on Clean Cookstoves. Her professional hobby is synthesis and integration, the most recent example being the 177-page “Bounding Black Carbon” assessment published in the Journal of Geophysical Research.