Date/Time
Date(s) - 20/07/2022
11:00 am - 12:00 pm

Zoom link available from gsamcgss@mcmaster.ca or chemrad@mcmaster.ca

Dr. Sumi Wren completed her PhD in Environmental Chemistry at the
University of Toronto under the supervision of Dr. Jamie Donaldson, where
she investigated the physical and chemical properties of ice surfaces, as
relevant to atmospheric processes. She then completed a short postdoc at
the University of Oregon under the supervision of Dr. Geri Richmond, where
she studied water surfaces relevant to atmospheric aerosol. In 2015, she
joined the Air Quality Research Division at Environment and Climate Change
Canada as a postdoctoral research fellow, where her research has focused on
quantifying vehicle emissions of air pollutants, and studying air quality and
climate impacts of oil sands emissions.

Are oil sands emissions of carbon dioxide
underestimated in official inventories?

The first part of the talk will provide and brief overview of Dr. Sumi Wren’s
educational and career path to her current position as a postdoctoral research
fellow at ECCC. The second part of the talk will focus on her current research on
quantifying CO2 emissions from the Athabasca oil sands region (AOSR). The oil
sands represent a significant and growing source of greenhouse gas (GHG)
emissions. Each year, oil sands facilities report their GHG emissions to the
Greenhouse Gas Reporting Program (GHGRP), which in turn informs the national
inventory report (NIR) submitted annually to the United Nations. These facility reported
emissions are so-called “bottom-up” emissions, which means they have
been calculated using emission factors, activity data, and expert judgement, but
how accurate are they? In 2018, the Air Quality Research Division conducted an
intensive aircraft campaign which measured pollutant emissions from surface
mining and in situ extraction operations in the AOSR. A new method for
estimating so-called “top-down” emissions of CO2 using the aircraft observations
in combination with reported and satellite (OMI and TROPOMI) derived emissions
of nitrogen oxides (NOx), which are co-emitted with CO2 during combustion, is
presented. The results indicate that CO2 emissions from both mining and in situ
operations are under-reported in official inventories, and a reconstruction of
historical emissions shows that this reporting gap has persisted for at least the
past 15 years. The size of the reporting gap is large (>65%) and reveals the need
for periodic validation of emissions inventories (and the “bottom-up” methods
used to produce them), which play a fundamental role in assessing the results of
climate action and in developing climate policy.