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The majority of greenhouse gas (GHG) emissions can be associated, in one way or another, with domestic consumption. Gasoline in our cars, steel in our appliances, beef in our chilies: extracting and manufacturing these commodities involves releasing carbon into the atmosphere.
Pinpointing domestic consumption does not mean excusing industrial polluters and state officials. Publicity promoting materialistic excess, the absence of alternatives and weak climate regulations do nothing to improve the situation.
However, seeing the problem through the lens of domestic consumption provides tools for action. This desire to change things, on an individual scale, comes up regularly in the messages that you send to the Courrier de la Planète.
A scientific article published in 2020 in the journal Environmental Research Letters, signed by Diana Ivanova, of the University of Leeds, and her colleagues, offers valuable insights. This article, quoted in the latest report of the Intergovernmental Panel on Climate Change (IPCC), quantifies the GHG reduction potential of the main “consumption options”.
Before diving into the results, let’s set the table. In 2017, each Quebecer emitted, on average, through their consumption, the equivalent of 8.0 tonnes of CO2. This is less than the North American average (13.4 tons), but more than the European (7.5 tons), world (6.3 tons) or African (1.7 tons) average.
Ms. Ivanova’s analysis looks at three main sectors: transport, food and housing. It compiles the findings of dozens of studies published between 2012 and 2019. For each consumption choice, it focuses on the average GHG reduction according to the studies consulted, but also on the range of results obtained by scientists.
Transportation
Avoid flying tops the charts for individual stocks. Not jumping on the plane for a long round trip saves 1.9 tonnes of CO emissions2 on average — between 0.7 and 4.5 tons, depending on the parameters considered.
Living without a gasoline car also has “substantial” climate potential, according to the authors. We are talking about a reduction of 2.0 tonnes of CO2 per person per year — between 0.6 and 3.6 tonnes of CO22depending on the distances traveled and the type of vehicle you stop using.
Switch to electric car reduces annual emissions by 2.0 tons of CO2 per person, on average (between 1.9 and 5.4 tons). In regions where electricity is clean, such as Quebec, the gains tend to be at the high end of the range.
Drive less, opt for active transportation and opt for public transit generate reductions ranging from 0.6 to 1.0 tonnes of CO2 per person per year. The definitions of the studies reviewed for these behaviors vary, but the idea is generally to avoid the car for short trips in the city.
Telecommuting, which reduces daily commuting, reduces emissions by an average of 0.4 tonnes of CO2 per person. However, the gains obtained in this way vary enormously from one study to another, according to this review carried out before the pandemic.
Carpooling and eco-driving provide modest reductions of around 0.3 tonnes of CO2 per person per year.
Feed
Adopt a vegan diet reduces its emissions by 0.9 tons of CO2 per year — between 0.4 and 2.1 tons — compared to the average omnivore.
Adopting a vegetarian or Mediterranean diet or opting for less carbon-emitting meats reduces its emissions by 0.5 tonnes per year, on average, according to the studies reviewed.
Eat organic reduced its emissions by 0.5 tonnes per year, mainly through agricultural practices that promote carbon sequestration in the soil and the abandonment of chemical fertilizers.
Choose local and seasonal foods generates annual reductions of 0.4 and 0.2 tons of CO2, respectively. The authors warn that the gains can evaporate if eating local requires heating a greenhouse or using heavy fertilizers.
Reduce food waste implies an annual reduction of 0.3 tons of CO2 per person, on average. Proper management of food waste that remains after this reduction—through compost, for example—is associated with negligible GHG reductions.
Housing and other consumer habits
Using electricity from renewable sources at home is associated with significant CO reductions2 in Ms. Ivanova’s study: 1.5 tonnes of CO2 per person per year, on average. In the Quebec context, where all homes are connected to clean hydroelectricity, this is already settled.
The use of heat pumps, the shift to a passive house or the use of smart thermostats are also associated with GHG savings, but this does not apply in a house heated with clean electricity.
Do not have a pet is typically associated, according to studies, with an annual reduction of 0.3 tons of CO2 per person.
Other drinking habits — such as using less textiles and plastic, using recyclable materials, recycling — generate negligible GHG reductions, according to the studies reviewed. This obviously does not mean that these behaviors do not have other environmental benefits…