Scope 3 emissions are the indirect greenhouse gases tied to everything a city buys, builds, uses, consumes and throws away, plus the emissions released producing those things outside its borders. For a city, that means the cement in a new library, the vehicles a contractor drives to a work site, the power a supplier uses to make street signs, and the waste a department sends to landfill.
It is a different question from how much a city burns on its own. A city’s direct operational footprint, the buses it runs and the fuel its fleet uses, is usually the smaller slice. The rest sits upstream and downstream in a value chain the city has influence over but no direct control of.
Most of the pages ranking for this term explain Scope 3 for corporations. That framing is useful but incomplete for local government, because cities report against a different standard, the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories, and because a city is not a trading company. It buys to build infrastructure that lasts sixty years, and the accounting has to survive a public meeting.
Table of Contents
- What Scope 3 Emissions Mean for Cities
- How Scope 3 Differs from Scope 1 and Scope 2
- Which Emissions Count as Scope 3 in a City?
- Why Scope 3 Emissions Matter for Urban Climate Goals
- How Cities Measure Scope 3 Emissions Without Guessing
- What Can Cities Do About Their Scope 3 Footprint?
- Start with procurement rules
- Set embodied carbon limits in construction
- Treat mobility as a consumption story
- Close the loops on waste and water
- Fix the data layer before the targets
- Disclose with a tier attached
- Frequently Asked Questions
- Are Scope 3 emissions included in a city’s emissions inventory?
- Can municipal governments reduce emissions they do not directly control?
- What is the difference between citywide and city organizational Scope 3 emissions?
- Which Scope 3 sources should a city measure first?
- How are Scope 3 emissions estimated when supplier data is unavailable?
- Does reducing Scope 3 emissions require changing procurement rules?
- Conclusion
What Scope 3 Emissions Mean for Cities
In simple terms, Scope 3 emissions are all the emissions that occur as a consequence of a city’s activity but outside its own operations. If a city’s boundary is city hall, the fleet depot and the water treatment plant, then Scope 3 is everything the city caused without burning anything itself.
Consider a city that builds a bus rapid transit line. The buses themselves, the diesel or electricity they consume, belong to Scope 1 or 2. The steel in the shelters, the asphalt under the lane, the concrete in the platform and the emissions from manufacturing all sit in Scope 3. So does the eventual disposal of the old signal cabinets, and the long tail of maintenance vehicle travel over the next forty years.
That matters because a Scope 1 and 2 inventory of a city can look like progress while the city’s real climate weight is elsewhere. UNEP’s Global Status Report for Buildings and Construction puts buildings and construction at roughly 40% of global CO2 emissions, and most of that weight is embodied in materials and supply chains rather than in operating a single building.
Here is the honest framing: Scope 3 is a leverage question, not a control question. A city cannot order a cement plant to decarbonise. It can write a bid document, set a standard, publish a scorecard and change what it buys next. Practitioners on sustainability forums say this plainly, and the frustration is highest wherever Scope 3 gets presented as something a team can simply reduce.
How Scope 3 Differs from Scope 1 and Scope 2
There are only three scopes in the GHG Protocol. There is no Scope 4, and any use of that term is informal or a misreading, something that shows up often enough in public comment to be worth stating plainly. Scope 1 is direct combustion. Scope 2 is purchased energy. Scope 3 is everything else in the value chain.
| What it covers | Where the emissions occur | City example | How controllable it is |
|---|---|---|---|
| Scope 1: direct emissions | Inside sources the city owns or controls | Natural gas boilers in a recreation centre, diesel in the sanitation fleet, refrigerants leaking from chillers | High. The city can change the equipment or the fuel |
| Scope 2: purchased energy | At the power plant or district energy system that serves the city | Electricity for streetlights and offices, district heating, cooling | Medium. The city chooses a tariff and a contract, not the generation mix |
| Scope 3: value chain emissions | Anywhere in the supply chain, upstream and downstream of the city | Concrete and steel in public works, employee commuting, contracted hauling, landfill of city waste, wastewater treatment | Low to medium. Influence comes from standards, procurement and disclosure |
The practical difference is who reports it and who owns the number. Scope 1 and 2 are usually metered or billed, so a city can count them with reasonable confidence. Scope 3 is assembled from estimates, supplier disclosures and emission factors, which is why the same city’s Scope 3 figure can move substantially when the underlying factors change without a single truck driving a different route.
Which Emissions Count as Scope 3 in a City?
The GHG Protocol defines 15 Scope 3 categories, eight upstream and seven downstream. A city’s inventory maps onto them unevenly. Some categories are enormous for a municipality, others barely register, and a few that dominate corporate inventories barely exist in local government.
| # | Category | What it looks like for a city |
|---|---|---|
| 1 | Purchased goods and services | Office supplies, IT hardware, cleaning contracts, catering, professional services |
| 2 | Capital goods | Concrete, asphalt, steel and equipment for roads, bridges, buildings and transit projects |
| 3 | Fuel and energy related | Transmission and distribution losses for electricity, and upstream refining and delivery of fuel |
| 4 | Upstream transportation and distribution | Freight moving materials and supplies to city facilities and work sites |
| 5 | Waste generated in operations | Paper, electronics, and debris from city operations and maintenance work |
| 6 | Business travel | Flights and rail for council, staff and officials travelling on city business |
| 7 | Employee commuting | Staff driving, cycling or taking transit to municipal workplaces |
| 8 | Upstream leased assets | Emissions from leased offices, depots and equipment the city does not own |
| 9 | Downstream transportation | Hauling of city waste, and delivery of goods to residents and businesses |
| 10 | Use of sold products | Emissions from products a city hands over, such as efficient appliances given away in a rebate program |
| 11 | Use of sold services | Services delivered to residents, such as transit trips powered by the city’s own fleet |
| 12 | End of life treatment | Landfill methane, incineration and recycling processing of city-generated waste |
| 13 | Downstream leased assets | Tenant energy in commercial property the city leases |
| 14 | Franchises | Emissions from concessionaire operations inside city facilities, such as a contracted parking garage |
| 15 | Investments and financed emissions | The share of a pension or reserve fund portfolio attributed to the city |
For most cities, categories 2, 1, 12 and 7 do the heavy lifting. Capital goods and purchased goods are the largest because public works dwarf the operating footprint of most organisations. Waste treatment matters more than teams expect, since methane from landfill is a potent gas and a city both generates and disposes of waste. Commuting is a smaller share than people assume, though it is the easiest to move with a modest policy change.
Two categories deserve a note. Category 15 has no direct operational equivalent, but a city that invests in funds can calculate an attributed share of financed emissions. And a city that publishes only the corporate categories is leaving out the ones that describe its own community, which is where the next section comes in.
Why Scope 3 Emissions Matter for Urban Climate Goals
Scope 3 typically accounts for 70 to 90% of a footprint once supply chains are counted, and upstream Scope 3 emissions run on average about 11.4 times larger than operational emissions, according to World Economic Forum analysis. For cities the share is even harder to dismiss, because so much of what a city does is procurement.
That raises the accounting question that matters most for city climate teams. Territorial accounting assigns emissions to where they physically happen, which lines up with Scope 1 and 2 and with the levers a government directly pulls. Consumption-based accounting follows the goods and services a place consumes, which pulls emissions from other regions into the city’s total and shows how much of a city’s footprint is actually produced elsewhere.
| Territorial accounting | Consumption-based accounting |
|---|---|
| Counts emissions released inside the boundary | Counts emissions released anywhere to produce what the city consumes |
| Maps to Scope 1 and Scope 2, and to city operations | Maps largely to Scope 3, and to consumption patterns |
| Points at fleet electrification, building efficiency, transit operations | Points at procurement standards, embodied carbon, housing and food policy |
| Matches the authority a city has | Matches the influence a city has through purchasing and land use |
Neither view is the correct one. C40 Cities and academic work on city footprints have estimated that urban areas account for roughly 87% of consumption-based emissions, which tells you how much of the problem happens in the places people buy and live rather than where things are produced. A city that only reports territorially looks cleaner than its residents’ actual consumption warrants, and that gap is the emissions leakage argument in its simplest form.
There is a third reason it matters. A climate action plan built only on Scope 1 and 2 will hit its numbers while the concrete keeps getting poured the same way. Adding Scope 3 changes which policies look worth funding, which is the argument a budget office needs to hear.
How Cities Measure Scope 3 Emissions Without Guessing
Cities use the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories, commonly called the GPC. It comes in two levels. GPC Basic asks for emissions sources within the boundary, in scope 1 and 2 terms. GPC Comprehensive adds scope 3, so a city can report what it consumes as well as what it emits.
The EPA’s Local Greenhouse Gas Inventory Tool, including its Government Operations Module, offers a lighter path for municipal operations specifically, and handles commuting and city solid waste without a full consultant engagement. For a first inventory, that starting point beats an attempt to cover all 15 categories at once. Practitioners consistently say the same thing on sustainability forums: start narrow with categories 1, 6 and 7, then widen.
Here is the workflow that holds up in a public report.
- Set the boundary. Decide whether the inventory covers municipal operations only or the whole community, and write the decision down. The two are frequently confused in public comment and the distinction decides which categories even apply.
- Pick the material categories. Run a screening pass across the 15 and keep the ones large enough to change a decision. Not every category needs a number in year one.
- Collect activity data. Tonnage of asphalt paved, litres of diesel purchased, tonnes sent to landfill, kilometres driven by staff. This is procurement, fleet and public works data, and most cities hold more of it than they think.
- Request supplier-specific data. Ask contractors and suppliers for product-specific emission data on the same specs you would ask for recycled content or delivery windows. The request is routine, and a data request from a public buyer is often the thing that gets a supplier to start tracking.
- Apply emission factors. Combine activity data with published factors, such as the EPA factors or the DEFRA conversion factors, and record which source and version you used.
- Estimate the gaps and label them. Spend-based estimates fill the remainder. State the tier out loud, because a number built from average factors should never be read as a measured one.
- Document, publish and revisit. Record assumptions, keep a base year, and improve the weakest categories each cycle.
The data quality hierarchy is the part that determines whether anyone trusts the result. Supplier-specific data sits at the top, average secondary data in the middle, and spend-based estimates at the bottom. Roughly half of large organisations report no Scope 3 figure at all, and the ones that do are frequently relying on the bottom tier. A city that publishes its tier with each number is doing something most reporters skip.
Why is it so hard, then? Five reasons recur. The emissions happen outside the city, so nobody is measuring them. Suppliers have no incentive to produce data a buyer has never asked for. Most results are estimates rather than measurements. Ownership is fragmented across procurement, HR, facilities, public works and finance, so no one team holds the whole picture. And the scope is incomplete by construction, because some of a city’s footprint, category 15 in particular, is genuinely impractical to attribute. Practitioners on ESG and small business forums describe spend-based estimates as unsatisfying and potentially misleading, and the better response is disclosure of the tier than pretending the precision is there.
What Can Cities Do About Their Scope 3 Footprint?
Order these by how much authority a city actually holds over the result. Procurement comes first because it is the one lever a city owns outright, and because public purchasing is large enough to move a market.
Start with procurement rules
A bid document can require environmental product declarations, recycled content thresholds, or take-back clauses. None of that needs new legislation if the purchasing ordinance already lets the city weigh sustainability criteria. Several cities have added embodied carbon limits to public works bids, and the shift lands in Scope 3 category 2 without anyone burning anything differently.
Set embodied carbon limits in construction
Because capital goods dominate a city’s Scope 3, building codes, low-carbon concrete specifications and material reuse targets move more of the city’s footprint than most efficiency programs do. Ask contractors for quantities of cement, steel and asphalt alongside costs.
Treat mobility as a consumption story
Transit service is usually counted as Scope 1 or 2, but the commuting, business travel and freight a city enables sits in Scope 3. Pricing parking, tightening low-emission zones and protecting bus priority move consumption patterns as well as vehicle miles.
Close the loops on waste and water
Municipal solid waste and wastewater are city-operated, which makes them unusual: they are Scope 3 categories the city partly controls. Composting, organics collection, landfill gas capture and sludge handling all have measurable returns.
Fix the data layer before the targets
This is where open city data and IoT telemetry come in. Smart meters, weighbridge data on inbound asphalt, fleet telematics and utility APIs replace spend estimates with real activity data. Cities that publish an inventory API let researchers, suppliers and internal teams check the numbers instead of trusting a PDF.
Disclose with a tier attached
Publishing the methodology, the base year and the quality tier of every figure builds more credibility than a round number would. It also answers the concern, raised repeatedly in practitioner forums, that Scope 3 reporting is compliance theatre. Details do the opposite of theatre.
Regulation is pushing in the same direction, and 2026 is an active year for it. The EU Corporate Sustainability Reporting Directive and the ISSB’s IFRS S2 standard push large companies to report value-chain emissions, which flows back to cities as buyers. California SB-253 sets a large-company emissions reporting deadline that cascades to suppliers. A procurement officer in any of those jurisdictions will eventually receive a supplier questionnaire, whether the city is ready or not.
Frequently Asked Questions
Are Scope 3 emissions included in a city’s emissions inventory?
Often, but not automatically. A city’s base inventory reports emissions released inside its boundary, which is Scope 1 and 2. Scope 3 is added at GPC Comprehensive level, or through the optional scopes in the EPA Local Greenhouse Gas Inventory Tool. A growing number of cities publish Scope 3 because citywide consumption-based figures show how much of a city’s footprint is produced outside it.
Can municipal governments reduce emissions they do not directly control?
Not directly, but they can change what they buy and how they build. Procurement standards, embodied carbon limits in public works bids, building codes, transit investment and landfill gas capture all reduce Scope 3 without the city owning the emitting asset. The honest framing is influence rather than control, and cities that overstate their control tend to stall once procurement hits resistance.
What is the difference between citywide and city organizational Scope 3 emissions?
City organizational Scope 3 covers the municipal government’s own supply chain: what city departments purchase, staff commute and travel, and waste they generate. Citywide Scope 3 covers the consumption of everyone living and working in the city, including residential energy, private transport and commercial activity. The two answer different questions and a city that publishes one under the label of the other invites real confusion.
Which Scope 3 sources should a city measure first?
Start with purchased goods and services, capital goods, waste generated in operations, and employee commuting. Those four cover most of a municipal footprint and all four sit on data the city already holds through finance, procurement and HR. Adding end-of-life treatment and business travel later is reasonable. Covering all 15 categories in the first cycle is how first attempts stall.
How are Scope 3 emissions estimated when supplier data is unavailable?
Using the data quality hierarchy. Multiply activity data, such as spend or tonnage, by a published average emission factor, such as the EPA or DEFRA sets, and record which factor and version you used. The result is a spend-based or average-data estimate, and it should be published at that tier rather than presented as measured. Ask suppliers for product-specific data in the next procurement cycle to raise the tier.
Does reducing Scope 3 emissions require changing procurement rules?
Not always, but it usually helps. Many cities can already weigh sustainability criteria in bid evaluation, which allows environmental product declarations, recycled content thresholds and take-back clauses without new ordinance. Where a city cannot, the levers that remain are specifications, waste and water operations, transit investment, and disclosure. Check what your purchasing authority already permits before drafting anything.
Conclusion
What Scope 3 emissions mean for cities is that the climate weight of a city sits mostly in things it bought rather than things it burned. Once supply chains are counted, Scope 3 is often the majority of the total, and it is the part a city influences through procurement, construction standards, mobility policy and honest disclosure rather than through direct control.
So the first practical action is small: map your largest Scope 3 sources before choosing reduction measures. Pull tonnage and spend from public works, procurement and fleet records, screen the 15 categories, and keep the four or five that dominate. Everything after that, the bid language, the embodied carbon limits, the disclosure format, gets sharper once you know where the mass actually sits.
