The colours of CO2 fluxes: enhancing public understanding of the “breathing” of ecosystems

With ongoing climate change, effective science communication has become increasingly important. Anthropogenic climate change, driven by excessive greenhouse gas emissions ‒ primarily CO₂ ‒ requires innovative solutions for mitigation. Among those, nature-based solutions have gained significant attention to offset some of the anthropogenic CO₂ emissions. One of the best available methods to study land-atmosphere CO₂ exchange, i.e., CO 2 fluxes, is the eddy covariance (EC) technique, which results in continuous long-term time series of half-hourly CO 2 fluxes. While such data are extensively used in scientific research, for instance to evaluate the impacts of climate change and land management on ecosystems, effective communication of these findings to the general public remains a challenge. Global and regional EC networks, such as FLUXNET and ICOS, hold a great potential to engage with lay persons to increase public understanding of climate change effects on ecosystems as well as of feedbacks ecosystems have on the atmosphere. Within the Swiss FluxNet, the Swiss national EC network, CO₂ fluxes have been measured across different land use types ‒ grasslands, forests, and croplands for many years and decades. Since measurements began at one site in 1997, five permanent measuring sites have been added since then. Now, the Swiss FluxNet has collected a total of 129 years of CO₂ flux data from these six long-term sites, and it continues to grow steadily. Such a research database also faces the challenges of an effective communication to the public. Therefore, we initiated an interdisciplinary collaboration between science and visual art. The goal was to create a visually engaging and meaningful representation of the flux data, using accessible and intuitive colours and an attractive design, thus simplifying scientific data without compromising content. The collaboration resulted in a figure that showcases annual CO₂ budgets across multiple sites with a uniform colour scale, highlighting year-to-year differences in ecosystem performance as well as typical characteristics of the respective ecosystem (Fig. 1). While the scientists provide flux data and information about the sites, the artist engages with the historical, artistic, and cultural significance of colours, and both partners address accessibility for colour-blind individuals. This approach involves a critical examination of how natural scenes are represented in artworks across diverse cultural contexts, how their corresponding colour scales look like and can be used, with insights from this research applied to the field of data visualization. First outputs of the project were presented at the Sustainable University Day at the University of Zurich and ETH Zurich in November 2024. The presented work exhibited the background research and the rationale behind the choice of colours (Fig. 2), and the scientific concepts of ecosystem CO₂ exchange as well as the final visual representation of the CO 2 fluxes (Fig. 1). The public, including individuals from diverse fields such as marketing, waste management, and sustainability, responded very positively, acknowledging the value of the collaboration and the clarity of the communication. This experience stresses the importance of interdisciplinary collaboration between science and art, showcasing how we can bridge the gap between complex scientific data and public understanding.