This study analyzes the language of climate activism using a Critical Discourse Analysis (CDA) approach, which reveals how activists construct urgency, moral responsibility, and systemic critique. The dataset comprises over 800 texts produced between 2018 and 2024, including speeches, social media posts, and protest signs. The study identifies rhetorical strategies that promote solidarity and mobilization, such as the use of collective pronouns (e.g., we, our) and crisis metaphors (e.g., climate emergency). Quantitative indicators TF-IDF, chi-square tests, and sentiment analysis reveal notable regional variation: activists in the Global South often appeal to colonial histories and justice, while those in the Global North emphasize generational responsibility. A further distinction is observed between youth-led and institutional movements. By combining discourse and quantitative analysis, the research demonstrates how language not only mobilizes action but also transforms climate discourse across sociopolitical contexts, offering deeper insight into environmental communication strategies in the 21st century.