Prior work on climate misinformation detection typically classifies individual comments or claims using text alone. This framing overlooks a key property of online climate discourse: misinformation is often produced, reinforced, and sustained through recurring rhetorical patterns that reappear across comments and threads. Using a large-scale TikTok climate discourse dataset, we construct discourse profiles by clustering climate-related comments into recurring rhetorical patterns. We then incorporate these profiles into fine-grained climate misinformation classifiers using a late-fusion architecture. Under video-disjoint evaluation across three training seeds, discourse-profile-aware models significantly improve macro-F1 over text-only baselines for bag-of-words, TF-IDF, and MPNet representations. RoBERTa-large exhibits a positive mean improvement but substantially greater variability, and the difference is not statistically significant. Beyond classification, our results show discourse profiles shape misinformation reception and propagation. Discourse-profile-conditioned language model agents exhibit misinformation acceptance patterns aligned with profile-level misinformation prevalence in ClimateDisc, and the relationship between misinformation prevalence and engagement persistence differs across dominant discourse profiles.
Figures & tables
Figure 1: Comparison of text-only vs. discourse-profile-aware misinformation modeling. (a) Prior work Islam et al. (2020) ; Coan et al. (2021) ; Upadhyaya et al. (2023) ; Choi et al. (2023) ; Rojas et al. (2024) typically predicts a misinformation category from comment text alone, treating each comment independently. (b) We construct discourse profiles by clustering comments and use discourse profile as additional context for misinformation-type prediction; the same discourse profile abstraction also supports discourse-profile-conditioned analyses of LLM susceptibility and engagement persistence.
Figure 2: Offline discourse profile construction: encode comments, cluster embeddings, and use GPT-5-based cluster consolidation to assign the resulting clusters to higher-level discourse profiles di (Section 3.1 ).
Figure 3: Late-fusion discourse-profile-aware misinformation modeling: obtain misinformation-type labels and evaluate prediction models that concatenate contextual text representations with discourse-profile embeddings before classification (Section 3.2 ). Details of how we obtain comment-level misinformation labels are in Appendix A .
Local / Experiential Observers
Ideological / Political Combatants
1. Local Weather Anecdotes
0. Anti-Trump/GOP/Biden
12. Storms & Flooding
11. Government Blame / Anarchy
13. Geographical Self-Mentions
18. Electoral Mobilization
Systemic / Structural Critics
Pro-Science / Rationalist
4. Consumption / Plastics Skepticism
14. Pro-Science / Anti-Misinformation
17. Energy / Policy Debate
Table 1: Discourse profiles obtained by grouping the 21 k -means clusters of comment embeddings into semantically coherent discourse-profiles. The Noise / Low-Signal group is excluded from downstream discourse-profile-sensitive analyses.
Representation
Text Acc
Prof Acc
Δ Acc
Text F1
Prof F1
Δ F1
Paired p
[MLP]
Bag-of-Words
0.690
0.709
+0.019
0.586
0.616
+0.030
0.028
TF-IDF
0.675
0.709
+0.034
0.522
0.601
+0.080
0.006
MPNet
0.799
0.808
+0.010
0.726
0.739
+0.014
0.015
RoBERTa-large
0.845
0.856
+0.011
0.794
0.810
+0.015
0.381
Table 2: Comparison of text-only ( Text ) and discourse-profile-aware ( Prof ) misinformation classification under video-disjoint evaluation. Accuracy and macro-F1 values are means across three training seeds. p -values are from two-sided paired t-tests comparing seed-level macro-F1 scores between the correct-profile and corresponding text-only models. Overall, correct-profile conditioning improves macro-F1 for bag-of-words, TF-IDF, and MPNet, while the RoBERTa-large difference is not statistically significant across seeds.
Figure 4: Within-Cluster Sum of Squares (WCSS; lower is better) and Silhouette Score (higher is better) across varying numbers of clusters k . The Silhouette score reaches a local maximum at k=21 .
Representation
Text F1
Shuffled F1
Correct F1
Correct − Shuffled
Significant seeds
[MLP]
Bag-of-Words
0.586
0.582
0.616
+0.034
3 / 3
TF-IDF
0.522
0.561
0.601
+0.041
3 / 3
MPNet
0.726
0.736
0.739
+0.003
1 / 3
RoBERTa-large
0.794
0.776
0.810
+0.033
1 / 3
Table 3: Permutation-test evaluation of discourse-profile conditioning across text representations. Shuffled-profile scores are first averaged across ten independent profile shuffles within each training seed; reported values are then averaged across the three training seeds. The last column reports how many of the three random seeds show a significant correct-vs-shuffled difference under the one-sample t-test. The correct-versus-shuffled advantage is most consistent for bag-of-words and TF-IDF, indicating that the specific profile assignment contributes most clearly in sparse lexical settings.
Discourse Profile
Susceptible (%)
Local / Experiential Observers
29.4
Ideological / Political Combatants
4.9
Systemic / Structural Critics
8.0
Pro-Science / Rationalist
10.4
Doomism / Nihilism
22.0
Conspiratorial / Anti-Climate
96.3
Table 4: Overall misinformation susceptibility rate by discourse profile. Conspiratorial / Anti-Climate profile exhibits the highest acceptance rate.
Figure 5: Mean persistence hours across misinformation level (Low, Mid, High) for each profile type.
Discourse Profile
H Statistic
Raw p
BH-FDR p
Systemic Critique
20.501
<0.001
0.003
Local Experiential
16.336
<0.001
0.003
Conspiracy
9.237
0.010
0.020
Pro Science
4.875
0.047
0.071
Political Combat
3.850
0.146
0.175
Doomism
2.912
0.233
0.233
Table 5: Within-profile Kruskal–Wallis tests examining whether persistence differs across misinformation tertiles (Low, Mid, High). BH-FDR denotes Benjamini–Hochberg correction across the six profile-level tests. Bold values remain significant at α=0.05 . After BH-FDR correction, persistence differs significantly across misinformation tertiles for Systemic Critique, Local Experiential, and Conspiracy.
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
Comment (ClimateDisc)
Matched Claim (QuotaClimat)
Climate change is a HOAX
Climate change is a complete hoax always has been.
Yes, climate change is real to what extent is arguable, but definitely changing
Climate change is definitely real. It changes every year from winter to autumn to spring to summer.
Climate change is very real. The climate has always changed, but in recent years it is changing too fast
Climate change is definitely real. It changes every year from winter to autumn to spring to summer.
Appendix
Table 6: Representative matched comment–claim pairs obtained using a cosine-similarity threshold of 0.85.
Cohen’s Kappa
Quality
>0.8
Almost Perfect Agreement
>0.6
Substantial Agreement
>0.4
Moderate Agreement
>0.2
Fair Agreement
0-0.2
Slight Agreement
<0
Almost No Agreement
Appendix
Table 7: Interpretation for different ranges of the Cohen’s Kappa values.
Comparison
Cohen’s κ
Human 1 ↔ Human 2
0.76
Human 1 ↔ classifier
0.57
Human 2 ↔ classifier
0.55
Appendix
Table 8: Cross-domain agreement on 100 randomly sampled ClimateDisc comments independently labeled by two human annotators.
Figure 6: Distribution of cluster/discourse profile sizes.
Category
BOW
TF-IDF
MPNet
RoBERTa
Science Unreliable
+6.8
+23.4
+0.5
+5.4
Not Bad
+5.7
+11.6
+1.8
+0.8
Not Happening
+4.3
+3.2
+0.6
+0.8
Not Human-Caused
+2.5
+2.6
+1.4
− 0.2
Fossil Fuels Needed
+1.2
+8.6
+3.6
+1.3
Solutions Harmful
+0.7
+4.0
+0.0
+1.7
Appendix
Table 9: Mean category-level F1 change from the text-only model to the correct-profile model, averaged across three training seeds. The misinformation categories in this analysis are inherited from the QuotaClimat taxonomy. Values are F1 percentage-point differences. RoBERTa denotes RoBERTa-large.
Technische Universität Berlin · German Research Center for Artificial Intelligence (DFKI) · BIFOLD – Berlin Institute for the Foundations of Learning and Data +1
University of Southern California, Annenberg School of Communication, Los Angeles, CA, United States · University of Southern California, Thomas Lord Department of Computer Science, Los Angeles, CA, United States