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Clean Air Online

Clean Air Connections

Clean Air, Climate Change and Stratospheric Ozone Depletion

Clean air, climate change and stratospheric ozone depletion are all part of a family of air-related issues.

As part of this family they share a number of similarities, or linkages, including:

It is important to understand the similarities and differences between clean air, climate change and stratospheric ozone depletion, especially as we hear about them in the news, experience them in our own lives, and try to make sense of it all. Sometimes it can be overwhelming and confusing, but it doesn't have to be.

Understanding the similarities can lead to opportunities that address, or co-benefit, all of these issues at the same time with the same approaches and policies.

Clean Air

Clean air issues, such as smog and acid rain, are issues that primarily influence the lowest part of the atmosphere, which is also the zone of air we breathe. Clean air is compromised by the presence of air pollutants that come from a variety of sources such as industries and our vehicles, and can have significant direct and indirect impacts on our health, the environment and the economy. These impacts may be experienced in the area near the source or sources of the pollution. Alternatively, some pollutants can be transformed and transported great distances by the wind, even across political boundaries, before falling back to the ground, water or within our communities.

Climate Change

Climate change refers to changes in the climate or long-term, average weather for a particular location. Climate change can be caused by natural processes, such as the change in the sun’s strength, and also by human activities, in particular those that alter the chemical composition of the atmosphere through the build-up of greenhouse gases (GHGs).

Collectively, GHGs act like a blanket and trap heat that comes from the earth. This blanket effect is natural and an essential part of life on earth. However, atmospheric concentrations of GHGs have grown significantly since pre-industrial times largely because of fossil fuel use and permanent forest loss, and are leading to accelerated changes in our climate. Wind patterns, precipitation, storm events, and temperatures will all be affected and will, in turn, impact life on earth.

Stratospheric Ozone Depletion

Stratospheric ozone depletion refers to the degradation of the earth's ozone layer and its ability to shield ultraviolet (UV) radiation from the Earth’s surface. Pollutants, such as chlorofluorocarbons (CFCs), destroy ozone (O3) in the stratosphere. These pollutants were more widely used in the past, but continue to be accidentally released from refrigeration and air conditioning systems, or come from using some solvents and foams.

The result is a thinning of the ozone layer, particularly in the Polar Regions. Any loss of ozone in the stratosphere will allow more ultraviolet radiation to reach the earth's surface, which has many significant impacts on human and environmental health, such as increased incidence of sun burns.

Stratospheric ozone depletion is a different issue than ground level ozone. In the case of stratospheric ozone, the concern is the loss of ozone in the upper atmosphere which protects us from ultraviolet radiation. However, the concern for ground level ozone is quite the opposite as we wish to reduce its abundance in the lower atmosphere. Ground level ozone degrades our air quality, impacting human and plant health, and is major component of smog. Unfortunately, ground level ozone cannot move or be shipped to the stratosphere.

Air Issues Matrix

Below is a table that highlights some important similarities and differences between clean air, climate change and stratospheric ozone depletion. This table is not exhaustive and does not fully reflect the complexities of each issue. Follow the links for more detailed information.

Clean AirClimate Change
 Stratospheric Ozone Depletion
General Issue Description
  • Clean air issues relate to the zone of air that we live in and breathe. They also impact soil and water systems.
  • Air pollutants degrade the quality of the air (i.e. air quality) and, in turn, compromise the goal of having clean air.
  • Air pollutants and their impacts can be localized around a source or travel great distances globally.
  • Smog and Acid Rain are key air quality issues.
  • Human-induced changes to the earth's natural greenhouse effect and its resulting impact on global climatic conditions.
  • Impacts are felt globally, but will vary from region to region. In particular, polar regions will see relatively higher temperature increases and can expect more significant climate impacts.
  • Human induced impacts on the earth's stratospheric ozone layer which reduces its ability to shield ultraviolet radiation from the earth's surface
  • Impacts that are experienced globally include a thinning of the ozone layer over middle and high latitudes as well as severe springtime depletion over the Antarctic, and in some years, over the Arctic.
  • Despite considerable action to protect the ozone layer, there is no clear evidence of a recovery.
  • Climate change may now be contributing to ozone depletion.
Impacts on Human Health and the Environment
  • Adversely affects human and wildlife respiratory, immune and circulatory systems leading to an increase in respiratory diseases such as asthma and possible premature death.
  • Individuals who are sick, elderly or very young are particularly vulnerable to air pollution.
  • Adversely affects many plant functions
  • Increases in temperature are expected to lead to increased frequency and severity of heat waves, droughts, floods and storms, changes to water levels and water quality and in the distribution of diseases.
  • Plants and animals become stressed and may not able to adapt - leading to reduced biodiversity and agricultural viability
  • Increased levels of ultraviolet radiation can lead to increased incidence of sun burns, skin cancer, and eye damage.
  • Plants and animals sensitive to ultraviolet radiation become stressed leading to reduced biodiversity and agricultural viability
  • Increased damage to freshwater and marine ecosystems
Key Pollutants
  • Greenhouse gases (e.g. carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), sulphur hexafluoride (SF6), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), chlorofluorocarbons (CFCs), and ozone (O3)
  • Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and halons (e.g. bromine)
Pollution Sources
  • Primarily, combustion of fossil fuels including coal, oil and gas within transportation (e.g. cars), energy production, industrial processes and many others.
  • Leaks and releases from certain synthetic chemicals.
  • Agriculture, livestock and chemical fertilizers
  • Waste and landfill material decomposition
  • Leaks and releases of synthetic chemicals from such things as older refrigeration systems, air conditioning, foams and cleaning solvents.
Time Scale of Effect (see Linking Today into Tomorrow)
  • Pollutants that contribute to poor air quality can be cycled out of the local environment in short periods of time (within a day) or persist over multiple days to weeks depending on the lifetime of the pollutant in the atmosphere and contributing factors such as weather.
  • Actions to reduce the amount of pollutants released or emitted can lead to air quality improvements on a relatively short time scale.
  • However, a few air quality pollutants such as heavy metals and POPs, can persist for much longer periods of time (e.g., hundreds to thousands of years).
  • Climate change effects tend to be more gradual and generalized, and so difficult to see. Observable effects may become apparent as trends across multiple years and decades, but will develop for possibly thousands of years and longer.
  • The effects or benefits of taking action today may not be seen for many to hundreds of years.
  • However, there is concern that the impacts of climate change will become more readily apparent in relatively shorter periods of time.
  • There is no evidence of ozone depletion prior to 1970. Models estimate that the recovery of the ozone layer can be achieved in about 50 years if all countries comply with the Montreal Protocol and its Amendments.
  • Climage change may also delay the rate of recovery.


For further information on understanding the linkages between Ozone Depletion and Climate Change:

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