Pettinelli, PaulinaFontana, MonicaPeired, Anna JulieLaranjinha, IvoKnoeller, SusiDemirtas, GulayFerreira, Ana CarinaHourmant, MaryvonneGracin, Sonja2026-01-222026-01-222026-020931-0509PURE: 149912469PURE UUID: f1c86591-687f-4bd8-9b34-588df0851a85PubMed: 41217276Scopus: 105028936131WOS: 001641088800001http://hdl.handle.net/10362/199639The urgency of climate change has prompted institutions world-wide to reassess their carbon footprints, and the scientific community is no exception. Large-scale medical congresses, such as the European Renal Association (ERA) Congress (Table 1 ), contribute substantially to carbon emissions. Nonetheless, these larger events provide immense value by fostering collaboration, networking, knowledge exchange and professional development. As a first step towards measuring carbon emissions, an estima-tion of the carbon footprint of air travel for ERA22 in Paris and ERA23 in Milan estimated at 1691 tons and 5808 tons of carbon dioxide equivalents (CO2 e), respectively [1 ]. These estimations had some limitations, as they excluded airport transfers and stopovers and were based solely on direct flights. Additionally, for ERA23, a higher number of participants lacked country of origin data, requiring assumptions based on average air travel [1 ]. Recognizing these limitations and reaffirming our commitment to sustainability, at ERA24 in Stockholm, we aimed to establish a more comprehensive and objective measurement of greenhouse gas (GHG) emissions. At this edition, ERA formalized its commit-ment by calculating the CO2 e associated with all the activities of the annual Congress. The first ERA24 Sustainability Report (available at: https://www.era-online.org/wp-content/uploads/ 2024/07/ERA-2024_Sustainability_Report_Short.pdf) has guided us to new strategies to reduce the environmental impact and create a lasting positive legacy [2 ]. The methodology followed the Greenhouse Gas Protocol, identifying and quantifying emissions across preparation, implementation and post-event stages (avail-able at: https://ghgprotocol.org/sites/default/files/standards/ Product-Life-Cycle-Accounting-Reporting-Standard_041613. pdf). An overview of the results obtained from ERA24 in Stockholm is shown in Fig. 1 . The CO2 e emissions per person were 2.083 tons CO2 e, with the main source being participants travel, accounting for over 89% of the total carbon footprint. In total, 7187 atten-dees traveled a total of 65.2 million kilometers. This equates to 1627 trips around Earth. While scientific congresses require sub-stantial resources, in-person events play a crucial role in the sci-entific community [3 ]. This article presents five key strategies to minimize the environmental impact among their challenges and limitations of the ERA Congress while preserving the benefits of in-person meetings and promoting a greener event.1110360engjournal article10.1093/ndt/gfaf242