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Non-CO₂ greenhouse gases included in CO₂ Performance Ladder

Of all greenhouse gases, CO2 has by far the largest share in man-made global warming. But other greenhouse gases, such as methane and nitrous oxide, have a much greater impact on the greenhouse effect per kilogram of emissions. The new version of the CO2 Performance Ladder requires companies to also report emissions of non-CO2 greenhouse gases. In this article, Ursula Zampieri and Bob de Boer of the Central College of Experts (CCvD) explain why this was chosen and what is changing.

The new version of the CO₂ Performance Ladder - version 4.0 - requires companies to report emissions of all greenhouse gases. Until now, this obligation only applied to emissions of the greenhouse gas CO₂, says Ursula Zampieri. ‘Other greenhouse gases could be reported if relevant, but that was only a recommendation.’

Why this change?

The main reason for the change, according to Zampieri, is that reporting on all greenhouse gases is the standard worldwide. ‘The CO2 Performance Ladder was still an exception in that sense. By reporting on all greenhouse gases, the CO₂-Performance Ladder is now in line with current guidelines and legislation, such as the Corporate Sustainability Reporting Directive (CSRD) and the Paris Climate Agreement.’

For companies themselves, the alignment also adds value, says Zampieri. ‘When you are working on emission reduction as an organisation, you want to know which activities have the most impact so that you can work on them. By also including non-CO2 greenhouse gases, you can make even more of an impact.’

What exactly are greenhouse gases?

Greenhouse gases are gases amplify the rate of global warming, the greenhouse effect. Since greenhouse gases absorb energy, they slow down the rate at which energy (in the form of heat) escapes into space. The greater the amount of greenhouse gases in the atmosphere, the more heat sticks around. As a result, the earth warms up.

Types of greenhouse gases

The Intergovernmental Panel on Climate Change (IPCC) distinguishes between four categories of greenhouse gases:

  • Carbon dioxide (CO₂)
  • Methane (CH₄)
  • Nitrous oxide (N₂O), also known as laughing gas
  • Fluorinated greenhouse gases (F-gases), such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3)

Global Warming Potential (GWP) 

The contribution a greenhouse gas makes to the greenhouse effect is expressed in terms of its Global Warming Potential (GWP). This is usually considered over a 100-year period. 1 GWP is equivalent to the impact of emitting 1 kilogram of CO₂ over 100 years.

GWP and CO₂ equivalent

The GWP of a greenhouse gas can  also be translated into its CO2 equivalent, thereby equating the impact of a greenhouse gas to CO2 emissions. Methane, for example, has a GWP of 27 (non-fossil methane) and 29.8 (fossil methane). That means the emission of 1 kilogram of methane is equivalent to the emission of 27 or 29.8 kilograms of CO2. Nitrous oxide (N₂O) has a GWP of 273. For some F-gases, the GWP is even many times higher.

Emissions of non-CO2 greenhouse gases

Almost every organisation deals with CO2 emissions within its own organisation and supply chain. These include the use of grey electricity in the office and workplace and fossil fuel for transport and industrial processes.

Emissions of other greenhouse gases take place on a much more limited scale. It is estimated that about 5 percent of the current CO2 Performance Ladder certificate holders emit greenhouse gases other than CO2 within their own organisation.

Methane emissions

Examples of organisations and places that may emit methane include:

  • Water boards, e.g. when removing dredged material and digesting sewage sludge,
  • Industrial dredgers, for example when dredging or when LNG (liquefied natural gas) leaks from ships,
  • Installation companies, for example when refrigerants leak while working on installations such as air conditioners or cooling machines,
  • Agricultural companies, where methane is released from livestock manure, and
  • Landfills, where methane is released during the decomposition of organic waste.

Nitrous oxide (laughing gas) emissions

Examples of processes and places where nitrous oxide can be emitted include:

  • Burning of fossil fuels,
  • Use of fertilisers containing nitrogen, and
  • Industrial sites where nitrogen plays a role in processes, such as sewage treatment plants.

Fluorinated greenhouse gas emissions

Examples of resources or activities that can emit fluorinated greenhouse gases include:

  • Refrigerants, e.g. for car air-conditioning, heat pumps and in stationary and mobile refrigeration systems,
  • Blowing agents, extinguishing agents and solvents,
  • Aerosol propellant, and
  • Engraving gas in semiconductor production.

Reporting non-CO2 greenhouse gases

In version 4.0 of the CO2 Performance Ladder, you map out where your organisation emits greenhouse gases in your operations or where there is a risk of greenhouse gas emissions. You report these emissions per greenhouse gas in your emission accounting. In addition, you convert your emissions per greenhouse gas into kilograms of CO2 equivalent. When you add these up, you arrive at a single footprint for all greenhouse gases.

Targets and measures

You then set reduction targets and measures to reduce or prevent emissions. Bob de Boer gives a few examples of this. ‘Think about disposing of dredge spoil faster, so that there is less methane emitted. Or detecting leaks early, so that no dangerous refrigerants or gases can escape.’

Greenhouse gas emissions in scope 3

Emissions of greenhouse gases can also take place in your supply chain - scope 3 emissions. To qualify for level 2 [GT1] or higher certification in the new version of the CO2 Performance Ladder, you must also work on emissions within your supply chain. Together with your chain partners, you will map (potential) greenhouse gas emissions and take measures to reduce or prevent them.

Other influenceable emissions (OIEs)

Besides scope 1, 2 and 3 emissions, there are also other greenhouse gas emissions that you as a company can influence, known as other influenceable emissions (OIEs). OIEs can also include other greenhouse gases besides CO2. In version 4.0 of the CO2 Performance Ladder, you must also identify these - if significant and relevant.

Contributing together to achieving climate objectives

Including all greenhouse gases instead of just CO2 ensures that the CO2 Performance Ladder is from now on in line with all current legislation and guidelines on greenhouse gas emissions. De Boer: ‘This way, the CO2 Performance Ladder and all organisations using it contribute to achieving national and international climate goals and a cleaner planet.’

Getting started with CO2 Performance Ladder?

- Find out here how to get your organisation certified with the Ladder 

 - Read here how to use the Ladder in tenders