2010 Progress Report - International Joint Commission

Progress Report 2010
the eastern parts of the country. 12 These results are
reported along with results from other modelling
studies in a synthesis report that was developed by
the U.S. EPA Global Change Research Program. 13
In Canada, modelling scenarios are underway to
evaluate a regional climate and air quality modelling
system against air quality observations for ozone and
PM 2.5
for current climate conditions. Further scenarios
planned for 2010–2011 will examine “climate change
(2050) with current emissions, and climate change
(2050) with projected future emissions.” All scenarios
are for summer months (June, July and August) over
a ten-year period.
Figure 45. Radiative Impact
of Short-lived Climate Forcers
A growing area of research involves air pollutants
(such as black carbon) that not only have adverse
health impacts, but along with other gases such as O 3
,
have a climate impact. These compounds are termed
collectively as short-lived climate forcers (SLCFs), as
their atmospheric lifetime is short in comparison to
other greenhouse gases, such as carbon dioxide (CO 2
).
A climate forcer affects the Earth’s energy balance by
either absorbing or refl ecting radiation. Some of the
shorter-lived forcers can have signifi cant impacts on
regional air quality, and their regulation can lead to
nearer-term, measurable benefi ts for air quality and
hence public health, as well as climate benefi ts.
Figure 45 illustrates the radiative impact of SLCFs.
Short-lived climate forcers such as black
carbon, methane and ozone may have
warming effects similar in magnitude to the
long-lived greenhouse gases such as CO 2
.
Estimates of the warming due to SLCFs
are still very uncertain and need to be
further refi ned.
Source: [AMAP] Arctic Monitoring and Assessment Programme. 2009. Update on
Selected Climate Issues of Concern: Observations, short-lived climate forcers,
Arctic carbon cycle, and predictive capability Oslo (NO). 23 p.
International Collaboration
International Transport of Air Pollution
In 2009, the National Academy of Sciences (NAS)
completed a study funded by the U.S. EPA, the NOAA,
the National Aeronautics and Space Administration
(NASA), and the National Science Foundation
(NSF), about the signifi cance of the international
transport of air pollutants for air quality, deposition
and radiative forcing. This study, entitled “Global
Sources of Local Pollution,” included the overarching
recommendation to develop and implement an
“integrated pollution source attribution” system. Such
a system would focus on improving capabilities within,
and integration among, emissions measurements and
estimates, atmospheric chemical and meteorological
modelling, and observations, including long-term
ground-based observations, satellite remote sensing
and process-focused fi eld studies. Figure 46 from the
NAS study shows the major atmospheric transport
pathways affecting North America.
12
Nolte, C G, Gilliland AB, Hogrefe C, Mickley LJ (2008), Linking global to regional models to assess future climate impacts on surface ozone
levels in the United States, J Geophys Res 113, D14307, doi:10.1029/2007JD008497.
13
[U.S. EPA] United States Environmental Protection Agency. 2009. Assessment of the Impacts of Global Change on Regional U.S. Air Quality:
A Synthesis of Climate Change Impacts on Ground-Level Ozone (An Interim Report of the U.S. EPA Global Change Research Program).
Washington (DC): Environmental Protection Agency. EPA/600/R-07/094F, 2009.
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