GREENHOUSE GAS INVENTORY: ACCOUNTING FOR THE CLIMATE
If we want to protect the climate, we need to know where greenhouse gas emissions come from and how much they amount to. This is where greenhouse gas inventories (GHG inventories) come in. They show how much climate-damaging gases a company, organisation or country produces. This allows for the planning of targeted measures, the monitoring of progress and transparent communication.
Data: *mobitool; #BAFU, 2025 (Switzerland)
The image has three overlapping circles. The dark central circle carries the title “How do I calculate my emissions?” and the rule: Emissions (in CO₂e) = amount × emission factor (EF). The light circle on the left gives a car example: mid‑size gasoline car, 1,000 km to Copenhagen, EF 151 g CO₂e per passenger‑km; a road trip for two equals 302,000 g = 302 kg = 0.3 t CO₂e. The circle at the top right shows a heating‑oil example: 1 tonne consumed, EF 3.16 CO₂e per tonne; result 3.16 t CO₂e.
Overall emissions can be measured and compared by calculating the emissions caused by various specific activities. This calculation is based on emission factors (EF): these indicate how much CO₂ (or other greenhouse gases, converted into CO₂ equivalents CO₂e) is released when a certain amount of a substance is used. One example is the combustion of oil for heating. The factors are determined scientifically and collected in places like the IPCC Emission Factor Database or the ecoinvent database.
GHG inventories form the basis for transparent pricing of emissions – whether in connection with CO₂e incentive taxes, emissions trading systems or voluntary compensation payments.
Graphics: Greenhouse Gas Protocol (modif.)
The diagram presents three large yellow‑orange columns labeled Scope 1, Scope 2 and Scope 3. Scope 1 (direct emissions) covers on‑site fuel combustion for power/heat/cooling, company vehicle travel, and on‑site production processes. Scope 2 (indirect emissions from purchased energy) shows emissions occurring at suppliers to generate electricity, district heat or cooling that are attributed to the company. Scope 3 (indirect value‑chain emissions) is split into upstream and downstream: upstream includes raw materials, purchased goods and services, transport/logistics, leased assets, capital goods, employee commuting and business travel; downstream includes distribution, use of sold products, end‑of‑life and recycling, franchise operations, investments and leased assets. Explanatory notes define upstream and downstream emissions, with icons (airplane, truck, factory, power lines, bin) illustrating categories.
DIRECT AND INDIRECT EMISSIONS
GHG inventories are compiled worldwide in accordance with the Greenhouse Gas Protocol (GHG Protocol). Emissions are divided into three scopes: direct emissions (Scope 1) and indirect emissions (Scopes 2 and 3).
Scope 3 emissions are particularly challenging: they make up most of the emissions but are outside the direct influence of a company. Since many companies are involved in the same processes, these emissions are often recorded twice – by manufacturers and buyers. This can motivate both sides to work together to develop more climate-friendly solutions.
Data: #BAFU, 2025 (Switzerland); ∆Fuel Emissions Trading Act (Germany)
THE PRICE OF CO₂
The CO₂e price is a key political instrument in climate protection. Those who emit greenhouse gases should pay for them – this creates incentives to avoid emissions. The price is determined in two ways:
- Countries set the price per tonne of CO₂e within their borders to steer behaviour towards climate-friendly solutions – these are known as incentive taxes.
- The trading of emission rights – i.e. certificates representing the right to emit a certain amount of greenhouse gases – creates a market. There, the price per tonne of CO₂e is determined by supply and demand.
COMPLIANCE CARBON MARKETS
A country or an organisation such as the EU sets an upper limit for greenhouse gas emissions. Within this limit, companies must possess the certificates necessary to cover their emissions. Those who emit less can sell their surplus certificates; those who emit more must purchase additional certificates or face additional costs or penalties. The trading takes place on compliance carbon markets, e.g., in the European Emissions Trading System (EU ETS).
Companies, especially those with high emissions such as airlines or cement or steel plants, often receive certificates free of charge from the state. This protects their competitiveness, as they would otherwise be at a disadvantage compared to foreign competitors without emission targets.
As part of the climate targets, the number of certificates will be gradually reduced until it reaches zero in 2050. At the same time, the prices for the remaining certificates will rise, further increasing the incentive to reduce emissions.
VOLUNTARY CARBON MARKETS
Companies and individuals can purchase CO₂ certificates on voluntary carbon markets to offset their emissions – e.g., for air travel or products. This is mainly a tool for taking responsibility and a climate protection measure that goes beyond legal requirements.
The certificates originate from climate protection projects such as reforestation, peatland restoration or solar energy, which bind or avoid CO₂ emissions. The price per tonne of CO₂e depends on the quality of a project (e.g., how complex, permanent and measurable the savings are), how many certificates are available and how high the demand is. Independent organisations verify whether emission savings are actually taking place. This is sometimes very difficult, as additional emissions savings are not always reliably verifiable and are sometimes overestimated.