Canada's official greenhouse gas accounts are published in the National Inventory Report, prepared by Environment and Climate Change Canada under international guidelines and submitted annually under the United Nations framework. It is the number that matters legally, the number against which targets are assessed, and the number almost every other source on this site ultimately draws on.
It is also the source of more confusion than any other document in Canadian climate debate, for one reason: what it counts is narrower than most readers assume.
Territorial accounting
The inventory uses territorial accounting. It counts emissions released inside Canada's borders. Three consequences follow, and all three drive live political arguments.
Exported fuel is not counted. Emissions from producing, processing and transporting a barrel of oil in Canada appear in Canada's inventory. Emissions from burning it in another country appear in that country's inventory. This is not a loophole and it is not unique to Canada — it is how every national inventory works, because counting both would double-count globally.
It does mean Canada can raise production while its own inventory stays flat or falls, and that both "Canada's emissions are declining" and "Canada is increasing global emissions" can be true at once. They are statements about different quantities.
Imported goods are not counted. Emissions from manufacturing an imported product belong to the manufacturing country. Countries that deindustrialise can show improvement that is partly relocation.
International aviation and shipping sit outside national totals under separate arrangements.
How sectors are divided
The inventory divides emissions into categories that do not map cleanly onto how people talk about them, and this produces avoidable confusion.
Oil and gas covers extraction, processing, transmission and refining — not combustion of the product by consumers, which appears under transport or buildings. Electricity covers generation only. Transport splits by mode. Buildings covers on-site fuel combustion but not the electricity consumed in them, which sits under electricity.
So a claim that buildings are a small share of emissions is true within the inventory's definition and misleading as a statement about the built environment's total footprint, because the electricity is counted elsewhere. Neither the claim nor the inventory is wrong. The categories simply do not mean what the words suggest.
Where uncertainty is widest
The inventory publishes uncertainty ranges, and they vary enormously by category. This is the most under-read part of the document.
Narrow uncertainty: fuel combustion where fuel sales are metered. If you know how much diesel was sold and its carbon content, the emissions follow arithmetically.
Wide uncertainty: fugitive methane from distributed sources, and land use, land use change and forestry. Fugitive methane is estimated from emission factors multiplied by equipment counts, and repeated aerial and satellite measurement campaigns have found more methane in the atmosphere above producing basins than bottom-up inventories predict. Forest carbon accounting involves modelling growth, decay and disturbance across an enormous land area, and wildfire makes annual figures extremely volatile.
Why this matters for targets
A percentage reduction target is measured against an inventory. If the inventory understates a category, a reduction measured against it delivers less real-world abatement than the headline implies, while reporting identically on paper. This is the strongest technical argument for measurement-informed inventories, and it applies regardless of one's politics.
Recalculation is routine
Each inventory recalculates the entire historical series using current methodology. When methods improve, history is restated so the series remains internally consistent.
This means a 2005 emissions figure quoted in 2019 may differ from the 2005 figure in the current report, and neither is wrong. It also means comparisons using figures from different vintages are invalid. Always take both endpoints from the same edition — a rule that disposes of a surprising share of bad arguments.
Who relies on this number
The inventory is not an academic exercise. Four things depend directly on it, which is why its boundaries are contested rather than merely technical.
Target assessment. Canada's international commitments are measured against it. Whether the country is on track is a statement about this document.
Policy design. Sector baselines for regulation, including industrial carbon pricing benchmarks, derive from inventory categories.
Equivalency agreements. When a province administers a rule in place of the federal one, equivalence is assessed against reported figures — which is why measurement method matters as much as stringency.
Trade measures. As trading partners introduce carbon border adjustments, national and sectoral emissions figures acquire direct commercial consequence for exporters.
That last one is the reason inventory quality is becoming a competitiveness issue rather than only an environmental one, and it is an argument for better measurement that does not depend on anyone's climate politics.
Using the inventory well
State the boundary whenever you use a figure. "Canada's territorial emissions" rather than "Canada's emissions" removes most ambiguity at the cost of three words.
Give the base year. A percentage without one is not a claim.
Check the uncertainty range for the category before treating a small annual change as a trend. In wide-uncertainty categories, a two per cent year-on-year move may be methodological noise.
Do not argue about which boundary is morally correct. Territorial accounting is the international convention, it is what targets are assessed against, and it is not changing soon. If you want to make a claim about consumption or export-related emissions, say so explicitly and cite a consumption-based study — they exist, they are legitimate, and they are a different measurement rather than a correction to this one.
Sources
- Environment and Climate Change Canada, National Inventory Report and methodology annexes.
- IPCC guidelines for national greenhouse gas inventories, on territorial accounting.
- Peer-reviewed aerial and satellite methane measurement studies, Western Canadian Sedimentary Basin.
Organisational descriptions reflect each body’s own published material and independent reporting as of September 2026. Funding arrangements and mandates change; check the primary source before relying on anything here.