Cars versus homes: A Q&A about greenhouse gas emissions in Edmonton

Gas-powered vehicles could be reaching the end of their lifecycle in Canada.

The federal government is giving automakers until 2035 to phase out the sale of new passenger vehicles powered by gasoline or diesel to increase more battery-powered cars and trucks.

While gas-powered vehicles are being phased out by their electric counterparts, a new study from the University of Alberta suggests that houses are bigger polluters.

On Monday,Edmonton AMhost Mark Connolly spoke withSandeep Agrawal, a professor at the university's school of urban and regional planning, who co-authored the study withpostdoctoral researcher Nilusha Welegedara.

His study was published in ScienceDirect.

What did you look at?

We wanted to look at the energy consumption by households across Edmonton and see whether it's the housing topology that's leading to greenhouse gas emissions versus transportation vehicles that they use.

What did you find?

What we found is buildings produce about 45 per cent more greenhouse gas emissions than personal transportation, which is opposite of what we think.

We also found that single-family detached homes consume more energy than any other type. When we look at our suburbs and neighbourhoods on the outskirts of Edmonton, they're generally more energy efficient.

But per capita greenhouse gas emission is much higher in the suburbs. And this is partly because of the increase in floor area for heating and cooling purposes. If you look at the suburbs, the single detached homes have much larger floor area, about 1,900 sq. ft compared to more mature neighbourhoods where the average is about 1,400 sq. ft.

There's a 40 per cent increase in the floor area which has to be heated and nowadays, it has to be cooled as well. A bigger house is going to cost you more, therefore more greenhouse gases.

Edmonton AM7:18Greenhouse gas emissions

A local researcher has found that the majority of your greenhouse gas emissions in Edmonton probably don't come from your car.

What made you want to explore this topic? What are you comparing it to?

We started off with Edmonton, but it essentially started from our own intellectual curiosity to see what happens vis-a-vis the greenhouse gas emissions and the primary drivers of greenhouse gas emissions in high latitude cities such as Edmonton.Now there is no exact definition of high latitude city, but we consider any city about 52 or 53 degrees parallel north. If you take this panel all across the globe, the other cities like this are Helsinki, Oslo, and Stockholm. These are the places which are facing a significant effect of climate change. They are warming at twice the global warming average and the surface temperature is tending to be much higher. We are also seeing more extreme weather events in Edmonton where summers have become so hot.

Are the bigger houses in the suburbs where most of theemissions arecoming from?

I wouldn't say that most of the emissions are coming from [them], but I will certainly say that usually we consider suburbs to be energy efficient, which is true. But if you look at the per capita emission, then suburbs are still emitting more emissions, partly because the houses have become much larger and they need more energy to be heated and to be cooled, and that is leading to quite a bit of greenhouse gas emissions.

So it seems like in this drive to make things more energy efficient, which we certainly have, not much attention has been paid to square footage and howbigger buildings are going to emit more greenhouse gas emissions. Is that true?

I would think so. I would preface that by saying that a lot of work has been done in making homes more energy efficient. A lot of attention is being paid, for instance, in solar panels and heat pumps and things like that, that the government is trying to incentivize.

But yes, I think our lifestyle now is such that we need bigger homes. The pandemicpartly contributed to it as well because now we need a space for users to have an office and things of that nature. So yes, over time, the floor area has increased quite a bit and with the changing weather patterns, not only do we need this way for heating, but also for cooling during the summer time.

What do you think we can do to reduce the emissions from our homes?

We should continue on the path of making homesmore energy efficient with solar panels, heat pumpsand energy efficient doors and windows. Those are absolutely the key.

We need to avoid the construction of monster homes. Constructing homes of smaller footprints, retro-fitting existing buildings which might not be so energy efficient and obviously utilizing more green resources. I think that's absolutely the key, especially for high latitude cities such as Edmonton.

I'm not in any way devaluing the importance of the use of personal vehicles. I mean, definitely reduction on the dependence of personal vehicles is another way of increasing public transportation systems. Making it more accessible to people is also important.

This interview has been edited for length and clarity.