The sad thing is that Canada is actually in one of the best places to make it's individual targets compared to most other countries. We're a rich nation with plentiful resources and all our needs are met domestically. Our major sources of greenhouse emissions are well known and clearly defined. They are also things that all have existing solutions to.
Even if complete elimination isn't possible, at least doing enough to reach our climate goals should've been easy. Heating and fossil fuel production account for more than 30% of our CO2 emissions, both things that could be replaced with electricity from clean sources like nuclear.
What we need isn't thousands of detached single family homes, but hundreds of low and mid-rise buildings that each house dozens. There is no system in the world that'll make single detached homes viable for the entire population. Not to mention that suburbs cost the government more in taxes than they take in, whereas high density neighbourhoods with mixed use buildings are second in economic revenue to downtown cores while providing massive amounts of housing.
I work at a place that spends over a million a year in rent because it uses space from the mixed use first floor of a 30 floor condo. There's dozens of stores like mine that do the same in the area. Imagine how much property tax the city gets from this? How much money must pass through each and every store to be able to afford such rent? And how pretty much every store in the area is doing pretty well despite stores just a few blocks away are crumbling and dying off because there's almost no housing in the area unlike this neighbourhood.
People wanting detached homes is fine. But what about us that don't care about such things? Why don't we get an option for a small but low cost home?