Carbon dioxide is a colourless, odourless, tasteless gas found naturally in the earth’s atmosphere. It is produced by natural sources like volcanoes, hot springs and geysers, people and animals (including fish), decay of organic materials, the combustion (i.e. burning) of fossil fuels, and as a by-product of some industrial processes like baking and brewing. Plants and algae use light to photosynthesize a compound called carbohydrate from carbon dioxide and water. Carbon dioxide is the primary source of carbon life; in other words, without carbon dioxide, there would be no life on earth.   Carbon dioxide is an essential element in human respiration; people breathe out about 40,000ppm (parts per million) CO2 with every breath. The quality of the air we breathe is sometimes impaired by certain contaminants, and it helps to know what these are. The main ones are:

• Particulate matter: Particulates are tiny drops of liquid and sold particles, the size of dust or smaller, suspended in the air. They come mainly from agriculture, construction and dust from roads, although various industrial sources play a role. Along with ozone, it is a major component of smog and, at high levels, can harm human health. (Often referred to as PM2.5 or PM10 – meaning Particulate Matter smaller than 2.5 or 10 microns in size.)
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  Chart showing diverse forms of airborne particulate matter according to size range.

  Nitrogen oxide: Nitrogen dioxide is a reddish-brown toxic gas with an irritating smell. Exposure to high levels of nitrogen dioxide can cause breathing problems and reduced lung function, and it is a component of acid rain.

• Ground-level ozone: Low-level ozone is a colourless gas that is formed through a chemical reaction of nitrogen oxides and volatile organic compounds in sunlight. The major sources of nitrogen oxides and volatile organic compounds are transportation, oil and natural gas production, electricity generation, home heating and even the burning of firewood. At high levels, ground-level ozone can cause breathing problems, lung damage, and asthma attacks in humans and damage to sensitive vegetation.
• Sulphur dioxide: Sulphur dioxide is a colourless and toxic gas that smells bad. It is caused both by natural sources and by human activity, the most important of which are smelting and refining, electricity generation, heating, and oil and gas production and other industries. Sulphur dioxide in high concentrations can contribute to breathing and heart problems, especially among infants and the elderly.
• Carbon monoxide: Unlike carbon dioxide, carbon monoxide is a highly toxic gas that is caused by the incomplete burning of oil, natural gas and coal. High levels of carbon monoxide can cause dizziness, unconsciousness, and even death.

      So, carbon dioxide does not affect air quality. It is, in effect, plant food. Those who call it air pollution are trying to present carbon dioxide as something it is not, in order to further a political agenda. Time lapse of plants with different CO2 concentrations: ~~~~ More resources: National Air Pollution Surveillance Program (NAPS) – Air quality in Canada is consistently monitored: “Today there are 286 sites in 203 communities located in every province and territory.” Provinces require reporting from industrial emitters at regular intervals; those who exceed air quality standards can be fined. https://www.ec.gc.ca/rnspa-naps/ Canada-wide, the GEM-MACH modelling system forecasts air quality based on diverse emissions input data including daily satellite data. https://weather.gc.ca/aqfm/index_e.html YourEnvironment – 100 year temperature data, air quality emissions and water quality are available for most communities in Canada at: www.YourEnvironment.ca Mother Nature also creates many air pollutants – including wildfire smoke, dust, pollens, spores and molds.  Aerobiology Research Labs provides monitoring and data for most locations across Canada (i.e. daily weather reports often include pollen counts) http://www.aerobiology.ca/  A plain language report by Dr. Thoenes, Emeritus Professor of Chemical Engineering, Eindhoven University of Technology, The Netherlands, on his view of carbon dioxide and climate change: https://www.friendsofscience.org/assets/documents/Thoenes_Views_CO2_Climate.pdf This article appeared on Friends of Science Calgary website at http://blog.friendsofscience.org/2017/10/22/the-carbon-dioxide-word-game/]]>