What is climate change?

Climate change is a significant change in the distribution and variability of the earth’s weather patterns driven by human-induced changes to the greenhouse effect. The last major shift in the climate was at the end of the last Ice Age, approximately 15,000 years ago, when the planet experienced a ~five degree increase in temperature over 5,000 years. By the end of the 21st century, it is estimated that global warming will increase the earth's temperature by two to four degrees centigrade (IPCC Working Group III, 2007). This increase in temperature will generate significant changes in climate at the global and regional level, influencing the way that we relate to the environment.

What are the different types of climate change?

Climate change can be divided into two related atmospheric phenomena. At a broad level, climate change represents a change in blanket climate conditions. For example, the earth’s climate as a whole can become hotter or colder. But, at a more specific or local level, this blanket climate change will manifest in sporadic and inconsistent changes in local weather and environment. Depending on local conditions, some areas may become hotter, while others may become colder. Similarly, some areas may become drier, while others may become wetter.

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What causes climate change?

The causes of climate change can be divided in two categories – natural and human causes. Natural climate fluctuations have always been part of the earth’s history, but the concentration of greenhouse gases in the atmosphere today has grown due to human activities.

The natural greenhouse effect is positive and required to sustain our diversity of life. Essentially, the earth’s atmosphere operates like a greenhouse (or glasshouse) and traps heat. The gases in the atmosphere function like a piece of curved glass surrounding the earth. As the sun’s rays pass through the layer of greenhouse gases and warms up the earth, the warm earth also gives off heat energy which radiates out into space. A portion of the heat is reflected back to earth.

The enhanced or human-caused greenhouse effect was introduced during the Industrial Revolution. Since then, humans have been using energy in greater quantities (ie, car engines and power plants) typically with the use of a process called combustion. Combustion (or burning) is a chemical reaction between a fossil fuel (such as coal, gas, or oil) and oxygen which emits carbon dioxide. The carbon dioxide produced through combustion thickens the earth’s existing greenhouse gases and increases the amount of heat reflected back to earth. As more carbon dioxide and other greenhouse gases with similar qualities are emitted, more heat is trapped in the earth’s atmosphere.

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What are the effects of climate change?

The effects of climate change are substantial, impacting our environment, health, society and the economy. 

Environment

Climate change will have a devastating effect on our environment. Examples include:

Health

Climate change has an impact on people’s health around the world. The United Nations World Health Organization reports that more than 150,000 people die each year from factors related to climate change (Shigeru Omi, WHO, Manila 2007). Climate change is anticipated to affect people in developing nations more severely. Examples include:

Society

Changes in weather patterns are likely to increase dependence on social and government resources especially in developing countries. These countries will experience a disproportionate impact due to poor physical and social infrastructure. As these populations and governments become strained, communities or climate refugees will start to migrate to countries with more stability and resources.

Economy

Warm temperatures will increase the physical risks to many industries, specifically infrastructure intensive sectors such as oil and gas, mining and forestry. Sectors that depend on sustainable environmental conditions, such as agriculture, are also likely to suffer. The regulatory response to climate change will likely impose significant costs on greenhouse gas intensive sectors. Governments, specifically in developing nations, will likely face increased economic instability as businesses shift resources towards adapting to the impacts of climate change.

What will Canada look like in the 2020's and the 2050?'s

As part of the Climate Change Adaptation Project, we partnered with the Canadian Climate Change Scenarios Network (CCCSN), a multi-stakeholder group affiliated with Environment Canada and multiple Canadian University climate research centres. CCCSN developed a series of ensemble model projections to demonstrate average temperature and precipitation scenarios in the 2020’s and 2050’s in Canada across our four seasons: spring, summer, fall and winter. These ensemble projections combine datasets from twenty-four international modelling centres to anticipate changes in the Canadian climate (CCCSN 2010).

Temperature 2020 Precipitation 2020
Temperature 2050 Precipitation 2050

Click to enlarge

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How can we adapt to climate change?

Adaptation involves making adjustments to our decisions, activities and thinking because of observed or expected changes in climate, with the goal of moderating harm and taking advantage of new opportunities. These adjustments range from improving infrastructure, switching crops to ones that better adapt to higher temperatures, etc.

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What opportunities are available through climate change adaptation?

As climate change occurs, adaptation can yield several different opportunities including:

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Did you know?

Canada's emissions of greenhouse gases, major contributors to climate change, rose 25% between 1990 and 2005.*

Driving a mid-size car about 5,000 kilometres results in about one tonne of emissions.*

In 2005, human activities released the equivalent of 747 megatonnes of carbon dioxide into the atmosphere in Canada. 1 megatonne = 1 million tonnes.*

In 2005, energy production and consumption accounted for more than 80% of greenhouse gas emissions in Canada.*

Fossil fuels are burned to move people and goods. In 2005, transportation activities accounted for 27% of all greenhouse gas emissions in Canada.*

Energy makes up one-fifth of Canada's merchandise exports.*

As worldwide demand for energy has surged since 1990, GHG emissions from the production of exported energy have jumped 146%.*

Canada has about 0.5% of the world's population, but contributes about 2% of the total global GHG emissions.*

Canada has warmed in recent decades. The trend between 1948 and 2007 shows a 1.4 °C increase in annual temperatures in Canada.*

Temperature increases between 1948 and 2007 have been greatest in the Yukon, Northwest Territories and northern British Columbia.*

Glaciers in the Rocky Mountains are receding and thinning, resulting indecreases in flow during the critical driest months of the year in some rivers.*

Of the 853 glaciers inventoried in 1975 in the North and South Saskatchewan River basins, 328 have disappeared completely.*

The spread of the mountain pine beetle in the central interior of British Columbia has coincided with warmer winter extremes.*

By 2007, 13 million hectares of British Columbia was infested by the mountain pine beetle.*

Canada has experienced heavier precipitation, intense wind storms and less predictable weather patterns over the past five years.*

The winter of 2009 was ranked in the top 10 "wettest winters" between 1948 and 2009.*

As of July 1, 2009, the median age of Canada's population was 39.5 years, up 0.2 years from the same date last year and up 3.1 years from 1999.*

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