AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Estimation for Location-specific Marginal Benefits for Primary and Precursor PM2.5 Emissions using the Adjoint of CMAQ
Amanda Pappin, Shunliu Zhao, Marjan Soltanzadeh, Burak Y. Oztaner, AMIR HAKAMI, Masoud Naseri, Mieczyslaw Szyszkowicz, Rick Burnett, Matt Turner, Shannon Capps, Daven Henze, Peter B. Percell, Jaroslav Resler, Jesse Bash, Sergey Napelenok, David Fahey, Rob Pinder, Armistead G Russell, Athanasios Nenes, Jaemeen Baek, Gregory Carmichael, Charles Stanier, Adrian Sandu, Tianfeng Chai, Daewon Byun, Carleton University
Abstract Number: 492 Working Group: Regional and Global Air Quality and Climate Modeling
Abstract Quantitative assessment of air pollution health impacts plays a key role in air quality regulation and decision-making. One metric with broad policy applications is marginal benefit or benefit-per-ton (BPT), which estimates the monetized public health benefit of reducing emissions by an additional ton of emissions at each location. Various models and methods have been used to quantify source-specific BPTs, but as a trade off to source-specificity, past estimates have been based on simplified models or simplifying assumptions. We use a backward sensitivity analysis approach, i.e. the adjoint method, to estimate BPTs on a source by source basis while accounting for all atmospheric processes as represented in a state-of-the-science air quality model.
Gridded emissions from SMOKE and meteorological fields from WRF are fed into the U.S. EPA’s CMAQ model v5.0 and it’s adjoint. Epidemiological concentration response functions (CRFs) considered for PM2.5 chronic exposure mortality include traditional effect estimates in Canada and the U.S., as well as the recently developed supra-linear CRFs from the Canadian Census Health and Environment Cohort (CanCHEC).
Our initial results for Canada estimate more than 9400 deaths annually to sources in Canada and the U.S., with a majority of impact coming from primary (organic and elemental) carbon emissions. For Toronto, we find BPTs of $820,000 and $650,000/ton for primary organic and elementary carbon emissions, respectively. Overall, emission-weighted averages of PM2.5 in Canada can be as high as $500,000/ton. We also combine our calculated BPTs with source-specific CO2 emission rates to estimate co-benefits of CO2 reduction from select sources. We find co-benefit estimates well above the social cost of carbon or its market price. For example, co-benefits from light-duty gasoline and heavy-duty diesel vehicles in large urban areas in Canada, are often in excess of $500 and $1000 per ton of CO2, respectively.