Climate Change 101

Climate Change Effects

This figure is from the Intergovernmental Panel on Climate Change's Fifth Assessment Report (IPCC AR5). It illustrates the widespread impacts that have been attributed to climate change across the globe.

Three categories of impacts are depicted:

1. Physical systems: includes glaciers, snow, ice and/or permafrost; rivers, lakes, floods and/or drought; and coastal erosion and/or sea level effects

2. Biological systems: includes terrestrial ecosystems, wildfire and marine ecosystems

3. Human and managed systems: includes food production and livelihoods, health and/or economics

This figure illustrates the relative contribution of climate change (major or minor) to the observed impact, the confidence in attribution and regional scale impacts. Evidence is strongest in the natural systems, i.e., the physical and biological systems. For North America, climate change has had a major contribution to impacts on glaciers, snow, ice and/or permafrost and terrestrial ecosystems. Climate change has had a minor contribution to impacts on wildfires. (http://ec.gc.ca/sc-cs/Default.asp?lang=En&n=A5F83C26-1)

This image shows a colour-coded map of Canada depicting temperature trends from 1948 to 2012. It illustrates that temperatures are warming across the country. Temperature increases range from up to 3°C warmer in Canada’s North to around 1°C warmer on Canada’s eastern coast.

Sea Level Rise

Climate change leads to rising sea levels as warmer temperature cause glaciers to melt and water to expand. Sea levels are predicted to rise by about 5 cm per decade over the next 100 years.

  Extreme Weather  

Extreme weather events such as droughts, storms, floods, forest fires, and ice storms will become more frequent and severe with climate change. This may already be affecting the weather in Canada and throughout the world. (Climate Change Exhibit)
While single storm events cannot be attributed to climate change, scientists predict that climate change will affect storm patterns and result in increased storm activity. Extreme weather events such as storms, floods, hurricanes and tornadoes can have devastating consequences. In 2006 in British Columbia, record dryness in August led to water shortages for residents and tourists, while in November and December, wind and rain toppled thousands of trees in Stanley Park and led to power outages, flooding, landslides and Canada's largest-ever boil-water advisory, affecting people in the Lower Mainland for over 12 days. (http://www.statcan.gc.ca/pub/16-201-x/2007000/10542-eng.htm)

Thawing Permafrost

Permafrost is ground that remains at or below 0°C for two or more years. Most of the world's permafrost has been frozen for millennia, trapping massive amounts of carbon in organic material. As this organic material thaws and decomposes, it releases greenhouse gases back into the atmosphere, further contributing to climate change.

 (Photo: http://climatestate.com/2013/06/18/estimating-the-permafrost-carbon-feedback-on-global-warming/ )

Melting Glaciers

A glacier is a large body of ice that develops on land where the accumulation of snow exceeds its ablation (melting and sublimation) over many years. Glaciers slowly deform and flow due to stresses caused by their weight. Canada has 1% of the global glacier coverage, third after Antarctica (84%) and Greenland (12%). (http://www.nrcan.gc.ca/environment/science/indicators-change/glaciers/11005)

Glaciers play an important role in the provision of fresh water. As snow accumulates and compacts, glaciers slowly proceed downslope under the force of gravity, eventually melting and contributing to streamflow at lower elevations. Glacial streamflow peaks in the hot summer months and provides moisture during the driest times of the year.

Some glaciers in the Rocky Mountains are receding and thinning, resulting in decreases in glacial streamflow during the critical driest months of the year. For example, the total glacial area in the North Saskatchewan River Basin decreased 22% from 1975 to 1998, while glacial cover decreased 36% in the South Saskatchewan River Basin. Of the 853 glaciers documented in these basins in 1975, 328 have disappeared completely.

Decreases in glacier size are most evident for smaller glaciers. Glacier contraction is likely accelerating as a result of higher air temperatures, less precipitation in winter and albedo feedback effects. (http://www.statcan.gc.ca/pub/16-201-x/2007000/10542-eng.htm)

Mount Revelstoke and Glacier national parks are home to 147 glaciers. Current research shows that our glaciers are shrinking. In 2011 8.3% of the parks were glaciated—down from 9.5% in 2000. Between 2000 and 2011, the surface area of glaciers in the two parks decreased by 12.7%, or 19.4 km2. (http://www.pc.gc.ca/eng/pn-np/bc/glacier/natcul/natcul1/glacier.aspx)

Ocean Acidification

About one third of carbon dioxide (CO2) released by human activities since the start of the Industrial Revolution in the 1800s has been taken up by the oceans. This addition of anthropogenic CO2 has altered the basic ocean chemistry, specifically the marine carbonate system. Carbon dioxide dissolves in the surface water and forms carbonic acid which has decreased ocean pH by 0.1 units over the past 200 years. If CO2 emissions increase as projected by the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios, by 2100, the global surface ocean pH will reduce further by 0.3 to 0.5 units.

The most direct biological impact of lowed pH will be on organisms that form calcium carbonate (CaCO3) shells and skeletons, because a decline in pH decreases the saturation state of CaCO3. The surrounding seawater needs to be saturated with carbonate ions to allow shells to form and to protect shells from dissolution (or breakdown into individual ions).

 (http://www.dfo-mpo.gc.ca/science/oceanography-oceanographie/impacts/acidification-eng.html)

Forest Fire Risk

These figures are from the British Columbia Forestry and the Canadian Forest Service. There are two maps showing circles representing the number and magnitude of wildfires. The first map depicts the conditions in 1999, where there are wild fires throughout BC, with none being very large. The second map depicts conditions in 2012 and shows several concentrations of large fires in the northeast and southern areas of British Colombia. (http://ec.gc.ca/sc-cs/Default.asp?lang=En&n=A5F83C26-1)