Helpful contacts and reference for the statistics and facts we share on this site.
Better Homes BC is the Province of British Columbia’s “one-stop shop” for finding all available rebates and incentives on air-source heat pumps.
The Better Homes BC website also offers a searchable tool of Heat Pump Program Registered Contractors who have completed additional training on heat pumps.
Sources, Methodologies, and Calculations
Since the climate and health risks of residential natural gas combustion are not yet widely understood, we offer the following supportive citations and calculations.
“Natural-gas kitchen appliances pollute your home with nitrogen dioxide (NO2), an air contaminant. If you cook with gas and have a child with asthma, your stovetop could be exacerbating their symptoms.”
- Zhu et al., April 2020. “Effects of Residential Gas Appliances on Indoor and Outdoor Air Quality and Public Health in California.” UCLA Fielding School of Public Health. Department of Environmental Health Sciences. [Source]
- Belanger et al., 2013. Household levels of nitrogen dioxide and pediatric asthma severity. Epidemiology 24(2):320-330 [Source]
- Delp and Singer, 2012. Performance Assessment of U.S. Residential Cooking Exhaust Hoods. Environ. Sci. Technol. 2012, 46, 11, 6167-6173 [Source]
- Garrett et al., 1997. Respiratory Symptoms in Children and Indoor Exposure to Nitrogen Dioxide and Gas Stoves. American Journal of Respiratory and Critical Care Medicine, Volume 158, Issue 3. [Source]
- Jarvis et al., 1996. Association of respiratory symptoms and lung function in young adults with use of domestic gas appliances. The Lancet, Volume 347, Issue 8999, 17 February 1996, Pages 426-431 [Source]
- Kile et al., 2014. A cross-sectional study of the association between ventilation of gas stoves and chronic respiratory illness in U.S. children enrolled in NHANES III. Environmental Health volume 13, Article number: 71 (2014) [Source]
- Singer et al., 2017. Pollutant concentrations and emission rates from natural gas cooking burners without and with range hood exhaust in nine California homes. Building and Environment, Volume 122, September 2017, Pages 215-229. [Source]
“...after an extensive review of this science, Health Canada issued new indoor NO2 safe exposure limits; they were then, and remain today, among the strictest limits in the world.”
- Health Canada. “Long-Term Residential Indoor Air Quality Guideline: Nitrogen Dioxide.” 2015-11-26. [Source]
- Brady Seals and Andee Krasner, Health Effects from Gas Stove Pollution, Rocky Mountain Institute, Physicians for Social Responsibility, Mothers Out Front, and Sierra Club, 2020. Page 19. [Source]
“Health Canada says that most existing Canadian gas ranges do not meet its long-term NO2 exposure standard.”
- Health Canada. Long-Term Residential Indoor Air Quality Guideline: Nitrogen Dioxide. 2015-11-26. [Source]
“British Columbia’s natural-gas homes together contribute the same amount of climate pollution each year as more than 870,000 vehicles.”
- FortisBC Inc. “Annual Information Form For the Year Ended December 31, 2019 Dated March 10, 2020.” Section 3.1. [Source]. (81 Petajoules of natural gas sold to residential customers in 2019.)
- Province of British Columbia. “B.C. Best Practices Methodology for Quantifying Greenhouse Gas Emissions” [Source]. (81 Petajoules of natural gas produces 4,029,750 tCO2e.)
- USEPA. “Greenhouse Gas Equivalencies Calculator” [Source]. Producing 4,029,750 tCO2e per year requires 870,602 vehicles.
- There were 3,914,217 vehicles registered in British Columbia in 2019. [Source]
“...one car, driven around the equator more than 400,000 times.”
- According to NASA, the diameter of the Earth at the equator is 12,756 kilometers (km).
Passenger vehicles are defined as two-axle four-tire vehicles, including passenger cars, vans, pickup trucks, and sport/utility vehicles.
In 2017, the weighted average combined fuel economy of cars and light trucks was 22.3 miles per gallon (FHWA 2019). In 2017, the ratio of carbon dioxide emissions to total greenhouse gas emissions (including carbon dioxide, methane, and nitrous oxide, all expressed as carbon dioxide equivalents) for passenger vehicles was 0.989 (EPA 2019).
The amount of carbon dioxide emitted per gallon of motor gasoline burned is 8.89 × 10-3 metric tons, as calculated in the “Gallons of gasoline consumed” section above.
To determine annual greenhouse gas emissions per mile, the following methodology was used: Carbon dioxide emissions per gallon of gasoline were divided by the average fuel economy of vehicles to determine carbon dioxide emitted per mile traveled by a typical passenger vehicle. Carbon dioxide emissions were then divided by the ratio of carbon dioxide emissions to total vehicle greenhouse gas emissions to account for vehicle methane and nitrous oxide emissions.
Due to rounding, performing the calculations given in the equations below may not return the exact results shown.
8.89 × 10-3 metric tons CO2/gallon gasoline × 1/22.3 miles per gallon car/truck average × 1 CO2, CH4, and N2O/0.989 CO2 = 4.03 x 10-4 metric tons CO2E/mile
- EPA (2019). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2017. Chapter 3 (Energy), Tables 3-13, 3-14, and 3-15. Environmental Protection Agency, Washington, D.C. EPA #430-R-19-001 (PDF) (113 pp, 3 MB About PDF)
- FHWA (2019). Highway Statistics 2017. Office of Highway Policy Information, Federal Highway Administration. Table VM-1. (1 pp, 12 KB About PDF)
“...nearly eight million round-trip flights between Vancouver and Toronto.”
- International Civil Aviation Organization. “ICAO Carbon Emissions Calculator” [Source]. (Per passenger CO2 emissions for this route are 1,007.6 kg.)
“Close to one million British Columbian households use natural gas... In 2019, the provincial natural gas utility connected an additional 10,000 homes to its service.”
- FortisBC Inc. “Annual Information Form For the Year Ended December 31, 2019.” March 10, 2020. Section 3.1, chart on page 7. [Source].
“Meanwhile, a recent Stanford University study found that natural gas stoves emit carbon pollution even when they are turned off.”
- Eric D. Lebel, Colin J. Finnegan, Zutao Ouyang, and Robert B. Jackson. “Methane and NOx Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes.” Environmental Science & Technology 2022 56 (4), 2529-2539 DOI: 10.1021/acs.est.1c04707 [Source]
- Jordan, Rob. "Stanford scientists find the climate and health impacts of natural gas stoves are greater than previously thought." Stanford News. January 27, 2022. Stanford Woods Institute for the Environment. [Source]
“Replacing a gas furnace with a heat pump is one of the biggest moves you can make for the climate. Depending on the age of your home, you could shrink your carbon footprint by up to 87 per cent.”
- “Upgrading natural gas heating systems to air source heat pumps represents the single greatest energy upgrade opportunity for delivering household green house gas emission reductions. Modelled data shows greenhouse gas emission reductions of 80% to 87% in homes built in 2000 or earlier and a 50% to 60% reduction in homes built after 2000." [Source: CityGreen Solutions Inc. “Energy and GHG Archetype Home Project Summary Report for the City of Vancouver.” November 2018.]
Heat pump exterior image courtesy Mitsubishi Electric Sales Canada Inc.