Concentrations of ground-level ozone have also decreased.
Over the last four decades, Canada’s carbon monoxide levels have dropped by 90 per cent.
Canada’s greenhouse gas levels have been declining since 2005.
The risks that hydraulic fracturing poses to air appear to be modest and manageable with current technologies.
As pretty much everyone in the world knows by now, Pope Francis published an encyclical recently On Care for Our Common Home, which discusses all things environmental—climate change, of course, but also air pollution, water pollution, sustainable development, the precautionary principle…the list goes on through 184-pages.
At the end of March, the CEO of the Ontario Power Authority (OPA) issued a directive regarding the implementation of Ontario's "Long term energy plan," which spells out what the provincial energy regulator plans to do to spur energy conservation.