Proposals for new mines, power plants, pipelines or railways in Canada will have to include plans to hit "net zero" emissions by 2050 if they have any hope of getting approved.
What began as a friendly rivalry between two southern Alberta towns has ended with what may be one of the most extensive programs of solar power anywhere in the country.
Canadian cities hoping to lead the charge on climate change action should be taking notes from the Texan capital of Austin, writes columnist Hamish Stewart.