According to the international comparative study "Health Care's Climate Footprint" by Health Care Without Harm (HCWH), the health care sector is responsible for approx. 57 million tons of CO₂e per year. At approx. 0.71 tons CO₂e per inhabitant and year, this corresponds to 6.3% of Germany's greenhouse gas emissions in 2017, with processes in Germany accounting for 35 million tons CO₂e or 62%. The contribution of the healthcare sector is thus roughly twice that of air traffic, which is very present in the media. The per capita emissions of the healthcare sector in Germany are high in international comparison and are 45% higher than the EU-28 average of 0.49 tons CO₂e per year.

A multi-stage literature and internet search identified only 62 hospitals and two clinic companies for Germany that record and publish their greenhouse gas emissions, which corresponds to about 12% of all hospitals in Germany. None of the hospitals or clinic companies recorded Scope 3 emissions, although two-thirds of the German healthcare sector's emissions are attributed to Scope 3. This justifies the approach of KliOL to record for the first time the greenhouse gas emissions of a German hospital from Scope 1 to 3 in order to be able to optimize climate protection measures. (Definition of the scopes: see project procedure)