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The Earth's climate is a complex system in which many factors interact to produce regional climates and local weather systems. Our climate has supported life on Earth for thousands of years.  But, today, we face the reality that human activities have altered the Earth's atmosphere and changed the balance of our natural climate.
Greenhouse gases (GHGs) such as carbon dioxide, methane and nitrous oxide exist naturally in the atmosphere, trapping heat and warming the air in much the same way glass warms the inside of a greenhouse. But human activities, including fossil fuel use and deforestation, also release these gases. (For instance, it is estimated that the global consumption of fossil fuels releases over 20 billion tonnes of carbon dioxide - the key factor in climate change - into the atmosphere every year).
The Kyoto Protocol
The Kyoto Protocol is an international agreement to take action on climate change negotiated by more than 160 countries in December 1997. Under the terms of the agreement, industrialized countries undertook to reduce their collective emissions of the six most important greenhouse gases (GHGs) by 5.2 percent below 1990 levels by the period 2008-2012.* Canada was an active participant in the negotiations and, as a signatory to the Protocol, has made a commitment to reduce its GHG emissions to 6 percent below 1990 levels by the same period.
The Kyoto Protocol presents a significant challenge for Canada´s economy. Reaching our target will require major changes in the way we produce and use energy at home, work and on the road. But there will also be opportunities through the development of energy-efficient products, services and technologies.
* Carbon dioxide, nitrous oxide, methane, halocarbons (chlorofluorocarbons and hydrochlorofluorocarbons), perfluorocarbons, and sulphur hexafluoride.
Is our world getting warmer?
Scientists around the world now recognize that the Earth´s climate is changing – our world is getting warmer. Extensive data demonstrates that the global climate has warmed during the past 150 years. This change was not a steady increase in temperature, but rather a series of warming and cooling cycles over intervals of several decades. The long-term trend, however, is one of net global warming. In tandem with this warming trend, alpine glaciers have been retreating, sea levels have risen and climatic zones are shifting.
Most scientists agree that average global temperatures could rise by 1 to 3.5 degrees Celsius over this century. In Canada, this could mean an increase in annual mean temperatures in some regions of between 5 and 10 degrees Celsius.
Such changes to our climate could have unpredictable and/or far-reaching environmental, social and economic consequences.
How will climate change affect us?
Climate change is more than a warming trend. Increasing temperatures will lead to changes in many aspects of weather, including wind patterns, the amount and type of precipitation, and the frequency and types of extreme weather events in a given area.
The effects of climate change will be felt differently in various regions of the world. Low-lying and coastal regions will be forced to cope with the impacts of rising sea levels, as increasing temperatures cause the oceans to expand. The increasing temperatures will melt glaciers and ice-cover over land, ultimately increasing the volume of water in the world´s oceans.
Scientific research is also showing that the effect of climate change will be greater in the world´s polar regions than nearer the Equator. This has serious implications for the sensitive polar ecosystems, their wildlife and human inhabitants. Continental interiors will experience greater warming than coastal areas with more frequent and intense heat waves. |
