In recent years, widely accepted scientific facts about climate change have become a polarizing and politicized issue that divides society into hostile camps. This is also fueled by growing hostility toward science and scientists, as well as the multiple political crises of the 2020s, which have led to widespread uncertainty and increased susceptibility to misinformation, disinformation, and conspiracy theories among the general public.

Against this backdrop, the final research report produced jointly by ISD Germany, the Hamburg University of Applied Sciences (HAW Hamburg) and the Leibniz Institute for Media Research (HBI) as part of the research project “NOTORIOUS”, examines the cross-platform dissemination of climate-related misinformation and disinformation.

This is the English translation of the German-language study “Destruktive Diskurse: Digitale Verbreitung von klimabezogener Mis- und Desinformation“ published in April 2025.

Key Findings:

• Semantic similarity to misinformation or disinformation narratives and the presence of far-right actors in posting clusters are effective indicators for identifying misinformation and disinformation in large datasets.
• Twitter/X and Telegram are important platforms for climate-related misinformation and disinformation, while Instagram is rather underrepresented.
• Private individuals, pseudonymous accounts, accounts that primarily share content from other accounts, and party-political accounts are responsible for a large proportion of posts classified as misinformation or disinformation.
• Both established and alternative media are used as sources: In addition to right-wing alternative media such as “Tichys Einblick” and “Junge Freiheit,” links to other posts on social media platforms are also used, as well as to daily newspapers such as “Die Welt.”
• Personal attacks and Delayism dominate the narratives and are used more frequently than climate change denial and climate skepticism.
• Discussions on climate change and climate protection serve as a starting point for more far-reaching criticism of the system by the far right.

Methodologically, this research report developed an approach, which takes into account the connections and interactions between different platforms in order to identify and analyze climate-related disinformation and misinformation narratives. To this end, between 2019 and 2023, 3.3 million posts from Telegram, Instagram, Facebook, and X (formerly Twitter) were collected based on climate-related keywords and further processed using natural language processing methods, language models, similarity networks, and hierarchical clusters.

Based on four technical indicators—semantic similarity to known misinformation and disinformation narratives, the presence of far-right actors within the posting clusters, the proportion of Telegram posts within the posting clusters, and a randomly selected sample—38 clusters with 1,484 posts were selected for further quantitative analysis. Nineteen posting clusters were also analyzed qualitatively in terms of the narratives used.

The report provides valuable insights into the mechanisms of “destructive discourse” in climate-related online communication. For example, it analyzes prominent actors, sources used, and narratives that fuel the spread of climate-related misinformation and disinformation.