That's easy. All they have to do is turn down the lights - street lights that is.
Street lights are by far the greatest single electricity use in a city, more than any single industry.
Can city dwellers learn to live with a little less illumination?
It's that, or live with the consequences of global warming.
In addition, leaving the lights on just burns up existing fuel suppllies that much faster, hastening the end of the petrochemical age.
Calgary has in motion a plan to replace all their street lights, currently, those yellow sodium vapour beauties, with low wattage LED bulbs. They expect to recover the capital cost of the new bulbs with electricity savings as the program is completed in two or three years.
Ironically, Calgary buys electricty generated by burning coal while Vancouver uses Hydro-generated power.