Observing the
Interrelations between
Climate, Health, and Air
Quality
LUKE, ASHER
1
Table of Contents
Abstract – 2
Introduction - 2
Relations between Climate, Air Pollution, and Health - 3
Discussion - 5
Conclusion - 5
References - 6
2
Abstract
Air pollution significantly influences health. As of 2017, air pollution has accounted for up to 7
million deaths annually with an even larger number of hospitalizations. Climate change is also a
factor that affects air pollution and public health. Climate change alters the mobility of primary
pollutants, specifically particulate matter, and contributes to the atmospheric intensity of
secondary pollutants such as near-surface ozone. This report explores the relationships between
climate change, air pollution, and air pollution-related health impacts. The purpose of this report
is to evaluate the evidence of climate change on air pollution and air pollution-related health
impacts and to identify future projections.
Introduction
Climate is a crucial factor that affects air quality. Climate is what influences the emission,
transport, dispersion, chemical transformation, and deposition of pollutants. The characteristics
of pollutants are influenced by variables such as temperature, humidity, and wind speed; factors
that all vary with climate change. In general, climate change is expected to worsen air quality in
densely populated regions such as urban or suburban cities. This is due to pollutants changing
atmospheric ventilation and dilution, this will make it more difficult for global air pollutants to
be expelled naturally. Air pollutants will also worsen air quality by changing precipitation
patterns and other air pollution removal processes (Fiore). Reduced air quality will directly affect
human health and alter ecosystems in a way that will affect human health and impact climate
change in a feedback loop (WHO, Hasse D).
Figure 1: Pollutant mobility
This report concentrates on two major forms of pollutants: the global population-weighted fine
particle concentration (PM2.5) and tropospheric ozone. Air pollution consists of many pollutants,
including particulate matter. The global population-weighted fine particle concentration (PM2.5)
is a common measure of the concentration of particulate matter in the air. These particles can
penetrate deeply into the respiratory system and pose a risk to increase mortality from respiratory
and cardiovascular diseases. Ozone is a molecule made from three oxygen atoms. Ozone in the
stratosphere protects the Earth from harmful ultraviolet rays from the Sun. However, climate
3
change has caused the formation of tropospheric ozone which acts as a greenhouse gas that is
bad for breathing and contributes to smog and greenhouse gases.
Studies suggest that climate change has already affected air quality. For example, a study
simulated that from pre-industrial (1860) to present (2020) the global population-weighted fine
particle concentration (PM2.5) increased by 5% and near-surface ozone increased by 2% due to
climate change (Fang). This change from pre-industrial to present resulted in approximately
130,000 air pollution related deaths due to climate change.
The purposes of this report are to describe the interrelations between climate change, air
pollution, and health, to evaluate projections on climate change and air pollution-related health
impacts, and to identify future projections of climate change and air pollution-related health
impacts.
Relations between Climate, Air Pollution, and Health
Climate, air pollution, and health have a relationship where climate can affect air quality, air
quality can affect climate change, and both can directly or indirectly affect health.
Figure 2: Climate, health, air quality interactions
The two major affects of climate change on air quality are the reduction of removal processes,
processes that help naturally purify the air such as rain and dispersion and amplifying
4
atmospheric chemistry which will increase the levels of pollutants (Fiore). Together, both these
factors can lead to a decrease in air quality.
As mentioned previously, climate change, health and air quality interact in a feedback loop. This
is because higher concentrations of PM2.5 from manmade sources result from changes in
emissions, meteorology, and the physical and chemical behavior of particles in the atmosphere.
However, the same changes in emissions, meteorology, and the behavior of particles in the
atmosphere are affected by an increase in temperature that is due to higher concentrations of
PM2.5, therefor creating a snowball affect the impacts the climate, air quality, and public health.
The effects of climate change due to air quality can have adverse effects on the environment. For
example, more frequent and larger wildfires associated with climate change could significantly
reduce air quality over the next several years. In turn, this negative affect on the environment
will impact human health and the loop will continue to repeat itself.
The interrelations between climate, air quality, and health are direct and indirect. First, particles,
especially from combustion, have been found to increase cardiopulmonary mortality, and
respiratory disease (WHO). Research has also shown that pollutants such as ozone are related to
all-cause, circulatory, and respiratory mortalities as well as chronic respiratory diseases such as
asthma (WHO).
Overall, pollutants such as PM2.5 and ozone can boost climate change and in turn affect public
health through more extreme temperatures. Pollutants such as ozone can also affect crop yields
that, in addition to climate, can affect food security and health. One study concluded that climate
change could reduce global crop yields by over 10% by 2050, significantly affecting public
health indirectly.
Overall, climate is expected to increase PM2.5 and ozone related mortalities (Fang).
Figure 3: Climate deaths projection
Figure 3 projects the rise in heat and cold related deaths from 2020 till 2080.
5
Discussion
One of the challenges with this report is that the results of studies are often projected under
unknown future scenarios. Therefore, there are underlying uncertainties relating to future
emissions and climate change that will impact future air-quality related health projections. In
addition, there is little consistency across studies in terms of what assumptions were made. For
example, almost all the studies evaluated use different scenarios of climate change, air pollution
emissions, time periods and base data. This makes it evident that comparisons of the studies are
very difficult because the studies used various possible greenhouse gas emission scenarios to
project future climate change and air pollution.
Conclusion
In general, climate change is expected to increase air pollution in the future. Studies have
projected larger increases in PM2.5 than ozone related health effects; PM2.5 being the main health
burden with air pollution. As climate change impacts vary globally, more studies are needed in
especially in regions that have higher concentrations of air pollutants.
6
References
Fang Y, Naik V, Horowitz LW, Mauzerall DL. Air pollution and associated human mortality: the
role of air pollutant emissions, climate change and methane concentration increases from the
preindustrial period to present. Atmos Chem Phys. 2013;13(3):1377–1394. doi: 10.5194/acp-131377-2013. [CrossRef] [Google Scholar]
Fiore AM, Naik V, Leibensperger EM. Air quality and climate connections. J Air Waste Manag
Assoc (1995) 2015;65(6):645–685. doi: 10.1080/10962247.2015.1040526. [PubMed] [CrossRef]
[Google Scholar]
Haase D, Larondelle N, Andersson E, Artmann M, Borgström S, Breuste J, et al. A quantitative
review of urban ecosystem service assessments: concepts, models, and implementation. Ambio.
2014;43(4):413–433. doi: 10.1007/s13280-014-0504-0. [PMC free article] [PubMed] [CrossRef]
[Google Scholar]
WHO . Review of evidence on health aspects of air pollution—REVIHAAP project: technical
report. Copenhagen: WHO Regional Office for Europe; 2013. [Google Scholar]
Tai APK, Martin MV, Heald CL. Threat to future global food security from climate change and
ozone air pollution. Nat Clim Chang. 2014;4(9):817–821. doi: 10.1038/nclimate2317.