Profesional de la información, 2023, v. 32, n. 2. e-ISSN: 1699-2407 1 Using algorithms to identify social activism and climate skepticism in user-generated content on Twitter Nuria Villagra; Ana Reyes-Menéndez; Jorge Clemente-Mediavilla; Dimitrina J. Semova Recommended citaton: Villagra, Nuria; Reyes-Menéndez, Ana; Clemente-Mediavilla, Jorge; Semova, Dimitrina J. (2023). “Using algorithms to identfy social actvism and climate skeptcism in user-generated content on Twiter”. Profesional de la información, v. 32, n. 3, e320315. htps://doi.org/10.3145/epi.2023.may.15 Manuscript received on 4 th November 2022 Accepted on 27 th April 2023 Nuria Villagra htps://orcid.org/0000-0002-2613-1530 Universidad Complutense de Madrid Facultad de Ciencias de la Información Avda. Complutense, 3 28040 Madrid, Spain nuriavillagra@ucm.es Abstract Climate change has become an issue of great relevance in society in recent years, and the data provided by the scientfc community recommend actng as soon as possible and forcefully. Scientsts, politcians, the media, and thanks to the new media, citzens and other social agents partcipate in the debate on this issue. Despite the data and general con- sensus in the scientfc community, the climate change debate is highly polarized, with skeptcal voices denying or ques- toning climate change and using social media to amplify the reach of their message. This can encourage misinformaton and polarizaton. This study tries to identfy the key indicators of social skeptcism around climate change through the analysis of users’ social actvism and behavioral paterns on Twiter. We analyze keywords, frequency, topics, and cate- gories from a sample of 78,168 tweets. The results show, frst, that there is an overlap of topics, with 24 of the 28 topics grouped in the intertopic distance map; second, that the size of the topics is relatvely small and linked to specifc events; and, third, that there is a signifcant politcal presence, especially from the United States. This work therefore contributes to the analysis of communicaton on Twiter about opinions against climate change. Keywords Climate change; Climate skeptcs; Skeptcism; Climate communicaton; Linguistc corpus; Algorithms; Social networks; Actvisms; Indicators; Social media; Behavior paterns; Opinions; Politcs; Polarizaton; Twiter. Nota: Este artculo se puede leer en español en: htps://revista.profesionaldelainformacion.com/index.php/EPI/artcle/view/87155 Ana Reyes-Menéndez htps://orcid.org/0000-0003-0636-9573 Universidad Rey Juan Carlos Facultad de Ciencias Jurídicas y Sociales Campus de Vicálvaro Pº Artlleros, s/n 28032 Madrid, Spain ana.reyes@urjc.es Jorge Clemente-Mediavilla * htps://orcid.org/0000-0002-9819-1129 Universidad Complutense de Madrid Facultad de Ciencias de la Información Avda. Complutense, 3 28040 Madrid, Spain jclemen@ucm.es Dimitrina J. Semova htps://orcid.org/ 0000-0001-8355-5121 Universidad Complutense de Madrid Facultad de Ciencias de la Información Avda. Complutense, 3 28040 Madrid, Spain djivkova@ucm.es Funding This work has been carried out within the project 2021-1-ES02-KA220-YOU-000029048 Green Artvism. This proj- ect has been funded with support from the European Commission (EC). This publicaton refects the views only of the author, and the EC cannot be held responsible for any use which may be made of the informaton contained herein.