The Facts about Climate Change
Greenhouse Gas Emissions (GHGs) and the "Greenhouse Effect"
- A natural system known as the "greenhouse effect" regulates the temperature on earth.
- When energy from the sun enters the Earth's atmosphere, approximately one third is reflected back to space. Of the remaining two thirds, some is captured by the atmosphere, but most is absorbed by the surface of the Earth as heat. As it warms, the Earth emits its own heat back into the atmosphere. Some of this escapes to space but, because it is emitted at longer wavelengths (infrared radiation), some of it is trapped by clouds and greenhouse gases (GHGs) such as water vapour, carbon dioxide, methane and nitrous oxide. This is the natural greenhouse effect, and by providing our planet with constant warmth and a breathable atmosphere, it is vital to sustaining life as we know it.
- Without the natural insulation provided by GHGs, the average temperature on Earth would be -18°C, instead of the current average of about 15°C, a difference of 33°C. Greenhouse effects caused by volcanic activity and bacteria allowed complex life to develop on Earth.
- We need GHGs to make our planet livable, but it is possible to have too much of a good thing. Because the concentration of GHGs in our atmosphere is increasing, our natural greenhouse is becoming more efficient at keeping the heat in.
- The most common GHG is water vapour. However, carbon dioxide (C02), methane (CH4) and nitrous oxide (N2O) are of special importance to our understanding of climate change because they are often produced by human activities.
- Each greenhouse gas affects our environment differently. Some are more effective at trapping heat, so their quantity does not have to be as great as another, although they may have a greater and longer lasting effect.
- The proportion of GHGs is less than one per cent of the total gases in the atmosphere. Although the concentrations of these gases are low, it is still possible for human-caused emissions to have drastic effects on the surface temperatures on Earth.
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Where GHGs come from
- GHGs occur naturally in our environment. When we excavate, refine, and burn fossil fuels such as coal, oil and natural gas, we release even more GHGs into the atmosphere. Since the Industrial Revolution, we have been burning ever-increasing quantities of fossil fuels to power our industries, generate electricity, heat and cool our homes, and power our vehicles.
- GHGs are naturally stored by living things and are released into the atmosphere when organic matter like wood is burned or decomposes. Other human activities such as the clearing of forested land for agriculture and urban development, and waste disposal methods such as landfill, have also led to an increase in the concentration of GHGs.
- As human societies have adopted increasingly sophisticated and mechanized lifestyles, the amount of heat-trapping gases in the atmosphere has increased. By increasing the amount of these gases, humankind has enhanced the warming capability of the natural greenhouse effect, disrupting the Earth's natural balance and causing environmental concern.
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How You Contribute to GHG Emissions
- Twenty-three per cent of Canada's greenhouse gas emissions are produced by individuals and families.
- Light-duty vehicles generate approximately 12 per cent of Canada's greenhouse gases. When an automobile burns gasoline, it produces CO2 — a major component of greenhouse gases.
- Air, rail, land (light and heavy duty traffic) and marine traffic are responsible for a total of 21 per cent of Canada's greenhouse gases.
- Canada consumes more energy (per person) than almost any other industrialized country.
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Weather
- More than a warming trend, increased temperatures and irregular weather conditions will lead to more frequent extreme conditions such as rising sea levels, droughts, hurricanes, tornadoes, thunderstorms, flooding and forest fires.
- Global warming is likely to have the greatest effect in the Polar Regions rather than at the Equator. This has detrimental implications for sensitive polar ecosystems, wild species and the human inhabitants living in and close to these regions.
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Health
- Climate change has the potential to seriously affect our health; particularly the health of young children, the elderly and those already in poor health who are vulnerable to asthma, heat stroke, dehydration, allergies, respiratory and cardiovascular illnesses.
- Warmer temperatures increase the range of parasites and the diseases they transmit such as West Nile virus, dengue fever, yellow fever, malaria and hantavirus.
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Food and Water Supply
- Warmer climates will cause warmer and shorter winters, contributing to lower water levels in our lakes and rivers, leading to poor water quality and an increase in waterborne diseases.
- Hot weather perpetuates the growth of microorganisms which can result in dangerous bacteriae and algae outbreaks at recreational beaches and infect shellfish and other marine life, making it toxic.
- Shorter and warmer winters increase the lifecycle of insects that wreak havoc on plant life and crops such as the pine beetle which are currently destroying forests on both the east and west coasts of Canada.
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What is Smog?
- "Smog" refers to a noxious mixture of air pollutants, including vapours, gases and particles that can often be seen as a yellowish-brown haze in the air – a visual indication of poor air quality. Smog is formed when the burning of fossil fuels in factories, power plants, transport vehicles and automobiles releases pollutants into the air. Some smog-forming pollutants are also greenhouse gases.
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