The Quietest Fifth of Your Footprint
What a 93-million-home study found about the emissions of simply living somewhere
🏠 The category nobody logs
Food gets photographed. Flights get remembered. But the gas boiler that runs all winter and the electricity that runs everything else produce emissions with no moment of decision attached to them — nothing to log, nothing to feel. They are, for most households, one of the largest single categories, and the one people are least able to describe.
The study
In 2020, researchers at the University of Michigan published what remains one of the most detailed pictures of residential emissions ever assembled. Benjamin Goldstein, Dimitris Gounaridis and Joshua Newell used data on 93 million individual households across the contiguous United States to estimate greenhouse gases from home energy use, and to separate out what actually drives them: climate, affluence, energy infrastructure, urban form, and building attributes such as age, housing type and heating fuel.
Their starting figure sets the scale of the problem. Residential energy use accounts for roughly 20% of greenhouse gas emissions in the United States. That is the electricity, gas, propane and heating oil consumed inside homes — before anyone has eaten a meal or driven anywhere.
Goldstein, Gounaridis & Newell (2020) — PNAS
“The carbon footprint of household energy use in the United States”
Reported findings:
- Residential energy use is roughly 20% of US greenhouse gas emissions
- Emissions per unit of floor space are lowest in Western states, highest in Central states
- Wealthier Americans have per capita footprints about 25% higher than lower-income residents, primarily because of larger homes
- In especially affluent suburbs, emissions can be 15 times higher than in nearby neighbourhoods
Proceedings of the National Academy of Sciences, 117(32), 19122–19130.
Geography does a lot of the work
The finding that is hardest to act on individually is also the most clarifying: ranked by state, emissions per unit of floor space were lowest in the Western US and highest in Central states. Two identical houses, identically occupied, produce very different numbers depending on the climate they sit in and the fuel mix of the grid they draw from. A kilowatt-hour is not a fixed quantity of carbon — it is whatever the local generating stock happens to be burning.
This is why a household footprint estimate that ignores location is close to meaningless, and why national averages are worth knowing before you judge your own number. It is also why the same efficiency measure pays back very differently in different places.
Floor space, not lifestyle
The affluence result is worth reading carefully. Wealthier Americans were found to have per capita footprints roughly 25% higher than lower-income residents — and the paper attributes this primarily to larger homes, not to some separate set of profligate habits. Space is the mechanism. More square metres is more volume to heat, cool and light, and the effect compounds with the building attributes that tend to travel with it.
At the extreme, the authors report that emissions in especially affluent suburbs can be 15 times higher than in nearby neighbourhoods. Fifteen times, within the same metropolitan area, under the same weather, on the same grid. Very little of personal-emissions variation is that stark.
A clean grid is not enough
The paper’s scenario modelling produced a split verdict. If the electrical grid is decarbonized, the residential housing sector can meet the 28% emission reduction target for 2025 under the Paris Agreement. But grid decarbonization alone was found insufficient to meet the 80% reduction target for 2050, for two reasons the authors name directly: a growing housing stock, and the continued use of fossil fuels — natural gas, propane and fuel oil — inside homes.
Meeting the 2050 target, they conclude, will also require deep energy retrofits, a transition to distributed low-carbon energy sources, reduced per capita floor space, and zoning for denser settlement patterns. In other words: cleaning up the electricity supply solves the electricity half. The combustion happening inside the building is a separate problem, and it is one that gets settled by heating systems and building fabric rather than by the utility.
What this means for tracking your own footprint
The study is about the United States, and its state rankings do not transfer elsewhere. What does transfer is the structure of the finding: home energy is a large share of the total, it is dominated by heating fuel and grid mix rather than by daily behaviour, and it is invisible unless you deliberately count it. Anyone building a personal footprint estimate from food and travel alone is leaving out a category of comparable size to the ones they are measuring most carefully.
That is the argument for tracking heating and electricity alongside everything else, rather than treating them as fixed background — see how they sit next to the reductions that actually move the number, and why intuition about emissions is such a poor guide.
📈 Counting the whole house, not just the plate
Decarbonr tracks 12+ lifestyle categories — heating, electricity, water, waste, digital and more — each colour-coded by impact, alongside food and 9 transport modes. Everything rolls into one daily number you can compare against national averages worldwide and against the 2-tonne annual target aligned with 1.5°C.
All of it stays on your iPhone — no account, no analytics, no ads. Read more about tracking home energy in the app, or the full list of sources behind the emission factors.
⚠️ Important note
The figures above are those reported by Goldstein, Gounaridis and Newell (2020) for the contiguous United States; they are not global values and should not be read as such. Decarbonr produces estimates, not measurements — emission factors are averages that vary by region, grid mix, season and building. This page is general information, not personalized environmental, financial or energy advice.