Do you know the CO₂-footprint of your dialysis facility?

We, GreenTec Dialysis GmbH, have developed this CO₂ -calculator specifically for dialysis facilities under the auspices of the "Kidney and Environment" commission of the German Society of Nephrology (DGfN).

The data from all dialysis centres in Germany are combined in one study. This allows us in dialysis to initially identify the current status. How does dialysis treatment compare with other areas of the healthcare system? What are the biggest sources of greenhouse gas emissions in the dialysis treatment process? How does the data from Germany compare internationally? Where can potential for improvement be identified?

The answers to these questions form the basis for the development and implementation of measures to reduce greenhouse gas emissions and thus also to lower operating costs.

First, it is important to determine where your dialysis centre currently stands in terms of its environmental footprint. Using this data, you can take steps to improve your dialysis's environmental footprint while reducing operating costs.

There are recognised standards for the calculation of the CO₂-footprint. The CO₂-calculator is based on the Greenhouse Gas Protocol (GHG) reporting standard .

The GHG Protocol divides emissions into 3 categories: Scope 1, Scope 2 and Scope 3. We have collected data from Scope 1, 2 and 3.

The accounting period is a full calendar year. The values from January 1 to December 31 of the respective year are used to calculate greenhouse gas emissions.

The data and equivalent values relevant for the calculations come from established and recognised databases (Ecoinvent) and sources (Bavarian State Office for the Environment (LfU), Federal Environment Agency (UBA)). The data is always up to date.

The basis for the design of the CO_2-eqfootprint calculator for dialysis centres are the Greenhouse Gas Protocol (GHG) reporting standards. All relevant emission sources according to Scope 1 and 2 and optionally Scope 3 are queried. Data is not yet available or publicly accessible for many processes that are not the dialysis centre operator's own corporate responsibility (Scope 3) (e.g. greenhouse gas emissions from the manufacture of dialysis machines, greenhouse gas emissions from the manufacture of medicines).

Therefore, for the development of a CO_2-eq-calculator, certain system boundaries must be defined. Only within these predefined system boundaries is a reliable, data-driven calculation based on actual, currently available data possible. With identical system boundaries and accounting periods, a benchmark between the different centres is possible.

The most abundant greenhouse gas released by humans in terms of quantity and overall impact on global warming is carbon dioxide (CO₂). Therefore, in this context, the term CO₂-footprint, is often referred to simply as "carbon footprint," although all greenhouse gases are included. To avoid misunderstandings, it is more accurate to refer to "carbon dioxide equivalent" (CO_2-eq) when other greenhouse gases are included in the calculation of the CO_2-eq -footprint. CO₂-equivalents (CO_2-eq) are a unit of measurement for standardising the various greenhouse gases.

Greenhouse gases are gases in the atmosphere that have an impact on the Earth's energy balance. They are responsible for the so-called greenhouse effect. In 1997, a binding international agreement to reduce anthropogenic greenhouse gas emissions was adopted in the Kyoto Protocol.

The best-known greenhouse gas is carbon dioxide (CO₂). Other gases, such as methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs / HFCs), perfluorocarbons (PFCs), sulphur hexfluoride (SF6) and, since 2012, nitrogen trifluoride (NF₃) are also present in the atmosphere and contribute to the greenhouse effect. These greenhouse gases are regulated in the Kyoto Protocol.

The concentration of greenhouse gases is subject to natural fluctuations (temperature, etc.). Due to human activity, the concentration of gases has increased significantly in recent years.

Standardised methods are used to calculate greenhouse gas emissions. The goal is to use activity data, such as electricity consumption, to calculate the CO₂-emissions. The calculation is carried out by multiplying activity data by defined emission factors.

The Greenhouse Gas Protocol is the most widely used standard for the preparation of greenhouse gas accounting. It is a globally standardised reference framework for measuring and controlling greenhouse gas emissions, for both the private and public sector, for value chains, and for CO₂ reduction measures.

It was introduced in the 1990s by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) and has been continuously developed further.

The international Ecoinvent database is currently the world's leading source of life cycle assessment data with over 2500 users in more than 40 countries. As the world's most consistent and transparent life cycle inventory database, it supports environmental assessments of products and processes worldwide.

The accounting period covers greenhouse gas emissions (GHG) for one year, starting on January 1 and ending on December 31 of the same calendar year.

When creating a corporate carbon footprint and the corresponding reporting system, Five fundamental principles must be taken into account:

• Relevance: It must be ensured that the system boundary and the company's GHG balance adequately reflect reality.
• Completeness: All emission sources and activities within the defined system boundary must be taken into account in the reporting.
• Consistency: The use of consistent methods is a prerequisite for comparing emissions over a longer period of time.
• Accuracy: It must be ensured that the quantification of GHG emissions systematically neither exceeds nor falls short of actual emissions (as far as this can be assessed). Any uncertainties must be reduced as much as possible.
• Transparency: All relevant topics must be presented in a factual, objective and comprehensible manner and must be verifiable.

The Greenhouse Gas (GHG) Protocol distinguishes between three categories, known as "scopes", to differentiate between different emission sources.

Scope 1: This category includes all CO₂emissions that can be directly controlled by the reporting company (direct CO₂-emissions). This includes the combustion of fossil fuels (mobile and stationary), CO₂emissions from chemical and physical processes as well as refrigerant leaks from air conditioning systems.

Scope 2: This category includes indirect CO₂emissions caused by the combustion of fossil fuels during the production of electricity, heat, cooling and steam by external energy suppliers.

Scope 3: All other CO₂emissions that are not under the direct control of the company are reported in Scope 3 (other indirect CO₂-emissions). This includes, for example, CO₂emissions associated with products and services that are utilised or processed by the reporting company. In addition, CO₂emissions associated with the use of sold products and services are included, if they cause direct CO₂emissions.

In accordance with the requirements of the GHG Protocol, the disclosure of CO₂emissions is mandatory in the Scope 1 and Scope 2 categories, but voluntary in the Scope 3 category.

The corporate carbon footprint is a company-related approach to greenhouse gas accounting. It considers direct and indirect greenhouse gas emissions along a company's value chain within a specified period.

The term "system boundary" in the preparation of a life cycle assessment is a tool for clearly separating the system under consideration from its environment. Therefore, the scope of the analysis must be defined in advance of any calculation.

There are organisational and operational system boundaries.

The organisational system boundaries describe the organisational unit and the period to which the CO_2-eqfootprint refers. The greenhouse gas emissions of one dialysis centre at a time are recorded and evaluated. If several centres belong together, the individual centre-specific CO_2-eq-footprint is calculated. It is possible to calculate a joint footprint for several dialysis centres belonging together.

The operational system boundaries describe the emission sources that are considered within the organisational boundaries. The operational system boundaries are based on the system of the Greenhouse Gas Protocol. The relevant categories for the healthcare sector according to the ADEME guidelines (Agence de la transition ecologique, pioneer in the field of carbon footprints in the healthcare sector) are taken into account.

The global warming potentials of the Intergovernmental Panel on Climate Change (IPCC) are widely accepted. These are published for different time horizons - 20, 100 and 500 years, taking into account the different residence times of gases in the atmosphere.

The Greenhouse Gas Protocol (GHG) product standard provides for a time horizon of 100 years. The calculation of emissions (stated as CO₂-equivalent (CO_2-eq)) is therefore determined by the Global Warming Potential (GWP).

The GWP indicates the extent of warming caused by a gas over a certain period of time. Global Warming Potential 100 (GWP 100) indicates the extent of warming over a period of 100 years.