The provinces and the federal government have decided to back a return to the emission levels of 1990 by the year 2010, though how this would be done is unclear. Local heat generation makes it warmer in a city's downtown than at the outskirts. Projections of further warming between now and the year 2100 range from 1 to 5 degrees Celsius and are based on models. A mid-range or consensus estimate from the various models is 2 degrees. They can err because all theoretical aspects cannot, by definition, be taken into account.
Scientists admit that their weather models are still relatively crude.
Others claim the models could be completely misleading. Thus wood, coal, gasoline and natural gas used for heating, power generation, or in automobiles and trucks all produce carbon dioxide. Each sector has been reducing emissions, using improved technologies. But we all work somewhere. Industrial expansion is needed to keep up employment.