Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released by people burning fossil fuels. The concentration of greenhouse gases has increased steadily during the 20thcentury into the 21st with carbon dioxide rising from under 300 ppm to 400 ppm. Electricity generation is one of the major sources of carbon dioxide emissions, providing about one-third of the total and one-half of the increase expected 2005-30. Coal-fired generation gives rise to twice as much carbon dioxide as natural gas per unit of power at the point of use, but hydro, nuclear power and most renewables do not directly contribute any.
Different parts of the world respond in different ways to warming from increasing greenhouse gas concentrations. The weather isn’t the only thing global warming will impact: rising sea levels will erode coasts and cause more frequent coastal flooding.
The study — Canada's Changing Climate Report (CCCR) — was commissioned by Environment and Climate Change Canada. It says that since 1948, Canada's annual average temperature over land has warmed 1.7 C, with higher rates seen in the North, the Prairies and northern British Columbia. In Northern Canada, the annual average temperature has increased by 2.3 C.
Along with these temperature increases, the CCCR says Canada is experiencing increases in precipitation (particularly in winter), "extreme fire weather" and water supply shortages in summer, and a heightened risk of coastal flooding.
Some of the key takeaways from the report included:
- The observed warming of Canadian temperatures are due to "human influence."
- There has been more rain than snowfall in Canada since 1948, a trend that looks to continue over the 21st century.
- Temperature extremes have changed in Canada, meaning extreme warm temperatures are getting hotter and extreme cold is becoming less cold.
- Extreme hot temperatures will become more frequent and intense.
- Over the last 30 years, the amount of snow-covered land has decreased in Canada.
- Flooding is expected to increase in Canada because of sea-level rise.
- Freshwater shortages in the summer are expected because warmer summers will increase the evaporation of surface water.
“The science is clear – Canada’s climate is warming more rapidly than the global average, and this level of warming effectively cannot be changed,” Nancy Hamzawi, said assistant deputy minister for science and technology at Environment and Climate Change Canada. Climate change is real, and Canadians across the country are feeling its impacts," Catherine McKenna, Minister of Environment and Climate Change, said in a press release.
The effects of global warming are also being felt by Canada's neighbor, Alaska. Last weekend, parts of Alaska hit temperatures of 30 to 40 degrees above normal, shattering previous records. "Between a rapidly changing environment and lack of societal response, I'm very concerned," climate expert, Rick Thoman of National Oceanic and Atmospheric Administration's Alaska Center for Climate Assessment and Policy.
Canada currently has one of the most ambitious carbon pricing programs in the world. Under Prime Minister Justin Trudeau, the Liberal government has enacted a nationwide tax on oil, coal and gas that starts at $15 per ton of carbon dioxide this year and will rise to $38 per ton by 2022. Most of the revenue will be refunded to Canadians on their tax bills; the government estimates that these refunds will offset higher energy costs for about 70 percent of people. The tax is a core part of Mr. Trudeau’s plan to reduce Canada’s emissions 30 percent below 2005 levels by 2030. The government unveiled legislation to overhaul environmental assessments of energy projects, paying more attention to greenhouse gas emissions. Critics say this will deter future investment at a time when existing projects are already in trouble.
Our assessment is that warming is not globally uniform. It can be noted that ocean temperatures increase more slowly than land temperatures because oceans lose more heat by evaporation and they have larger heat capacity. Canada being a high latitude regions warm faster than the global average due to positive feedback from the retreats of ice and snow. We feel that Canada remains mired in a political battle over climate policy which disobliges with the current conditions.