Kältere Waschkampagne #Wirdrehenrunter

Wissenschaftliche Unterstützung der deutschen Kampagne zur Verhaltensänderung durch verhaltenswissenschaftliche Erkenntnisse und ein Evaluationsdesign

Have you every pondered much on which temperature you usually do your laundry? Chances are it is higher than needed, as washing detergents have improved over time and deliver just as good results in lower temperatures. Available data suggests that turning down your washing temperature is a powerful contribution to climate protection. Switching from 40°C to 30°C of washing temperature can save up to 38% CO2 emissions while switching from 60°C to 40°C can save up to 46% of emissions (Umweltbundesamt, 2015). Colder washing is however not yet very established as a sustainable behaviour and washing at higher temperatures is a routine most people don’t question.

In diesem Zusammenhang, WWF Deutschland und der Konsumgüterhersteller Procter & Gamble (P&G) Deutschland have launched a cooperation in 2024 aiming to raise consumer awareness on this issue. The Germany-wide campaign #Wirdrehenrunter is carried out by P&G’s brand Ariel and WWF with the key goal to reduce Germany’s average washing temperature and thus cut down the overall CO2 footprint.

Since the beginning of the cooperation, CSCP has scientifically supported the campaign development by introducing behavioural insights into the campaign design and the process of developing a scientifically-sound methodology to assess the success of the campaign in terms of washing temperature reduction and overall impact. Since the campaign was launched, the CSCP is evaluating changes in washing behaviour every year.

The evaluation design for the campaign to measure changes in washing temperature and evaluate how and to which extend the campaign managed to drive behaviour change combines quantitative and qualitative methods at different stages before and after the campaign and has been reviewed by an external expert panel.

Four years of data now show a clear development. Germany’s average washing temperature decreased from 43.20°C in May 2022 to 40.76°C in May 2026 – a reduction of 2.44°C. The 2026 average was statistically significantly lower than both the 2022 baseline and the 2025 measurement. These changes were not observed in the control market of Austria, where the campaign was not run. Based on the measured 2.44°C reduction, the estimated greenhouse gas savings amounted to 119,684 tonnes of CO₂-equivalent over the most recent 12-month period and approximately 311,906 tonnes of CO₂-equivalent across the four years of the campaign.

Beyond #WirDrehenRunter, the project demonstrates how behavioural science, campaign design and rigorous impact measurement can work together to make everyday sustainability interventions measurable – and to generate evidence that can inform future behaviour change campaigns.