Tuesday, December 1, 2015

The Science of Climate Change - Environment Canada Report

Here are some excerpts from the presentation given to Canadian Prime Minister Justin Trudeau and the provincial Premiers at the recent summit on the eve of their departure for COP21 in Paris.

The report says that the evidence for anthropogenic warming is "unequivocal" and it suggests that Canada is already "warmer, wetter and stormier." The impacts of climate change are to be found in droughts, wildfires, and storm surges. Even more troubling is the melting of Arctic permafrost. Unchecked climate change will wreak havoc on forests, agriculture, ecosystems, and water.

Here are the five key messages contained in the report:
  1. Warming over the 20th century is indisputable and largely due to human activities.
  2. Canada’s rate of warming is about twice the global rate: a 2ºC increase globally means a 3 to 4ºC increase for Canada.
  3. Effects will persist for centuries because greenhouse gases (GHGs) are long-lived and the oceans are warming.
  4. Cumulative CO2 emissions largely determine ultimate warming. A 2ºC warming target may still be attainable, but we are already 65% of the way to the associated carbon limit or budget and global emissions must peak before mid-century.
  5. GHG emissions need to become net zero in order to stabilize climate at any temperature.

Here is the summary from the report:
  • The science is conclusive: Warming is unequivocal and human influence on the climate system is clear.
  • Impacts of a changing climate are already being felt, and they will increase with further warming. Adaptation will be needed to manage the risks.
  • The cumulative total emissions is what determines the ultimate level of warming. To avoid exceeding 2°C, global GHG emissions need to decrease rapidly.
  • GHG emissions need to become net zero in order to stabilize climate at any temperature.

To see the full presentation click here.

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