Life on Earth is possible because of the warmth of the sun. While some of this incoming solar radiation bounces back into space, a small portion of it is trapped by the delicate balance of gases that make up our atmosphere. Without this layer of insulation, Earth would simply be another frozen rock hurtling through space. Carbon dioxide (CO2) is the most important gas in this layer of insulation.

Carbon is stored all over the planet — in plants, soil, the ocean, and even us. We release it into the atmosphere as carbon dioxide through activities such as burning fossil fuels (coal, oil and gas) and cutting down trees (the carbon dioxide released into the atmosphere remains for 100 to 200 years). As a result, today's atmosphere contains 32 per cent more carbon dioxide than it did at the start of the industrial era.
 
This leads to an increasing concentration of carbon dioxide in our atmosphere, which in turn causes the average temperature on Earth to raise. Since 1990, the global average temperature has risen by 0.6 degrees Celsius, and the northern hemisphere is substantially warmer than at any point during the past 1,000 years. By disrupting the atmospheric balance that keeps the climate stable, we are now seeing extreme effects around the globe such as extreme weather events (David Suzuki, 2011).