Canada is the world’s third largest producer of greenhouse gases. Only Australia and the United States produce more.
Scientists agree that climate change is caused by human activities. Human activities create greenhouse gases at a faster rate than they are created naturally. The most important greenhouse gases are carbon dioxide, methane and water vapour.
Main causes
Carbon Dioxide is released into the atmosphere when fossil fuels are burned. Fossil fuels include coal, oil and gas. Fossil fuels are burned by cars and other vehicles, factories and power plants.
Methane is produced when organic matter decomposes. Methane also exists in deposits under the surface of the Earth. Sources of methane include livestock manure, garbage and rice paddies.
Water vapour is not directly created by human activities. However, when temperatures in the atmosphere increase, the amount of water vapour also increases. More water vapour then leads to warmer temperatures.
Deforestation also contributes to climate change. Trees absorb carbon dioxide from the air and release oxygen. Deforestation, or the removal of trees, is occurring around the world at a rapid rate. The more trees that are removed, the less carbon dioxide is absorbed. This leaves an excess of carbon dioxide in the atmosphere.
Climate change leads to more climate change
In the North, the snow and ice usually reflect a lot of sunlight and heat away from the land. Warmer temperatures have caused the snow and ice to melt. Sunlight and heat now reach the land and are absorbed, making the land even warmer.
Climate change is also causing the permafrost (permanently frozen land) to melt in the North. There is a lot of carbon dioxide and methane stored in permafrost. When permafrost melts, greenhouse gases are released into the atmosphere.
