Social media influencers, particularly those focused on sustainable practices, significantly impact consumer be-havior and environmental consciousness, influencing purchasing decisions to political activism, thereby playing a pivotal role in addressing climate change. The purpose of this cumulative dissertation is to identify the influ-ence process, effect, and utilization of green influencers. This endeavor is structured around three manuscripts, each addressing distinct research inquiries. Paper A delves into the correlation between influencers and their followers, specifically examining how prior green consumer attitudes influence this relationship. Paper B focuses on the characteristics of effective messaging by green influencers, providing insights into how these influencers can most persuasively advocate for sustainable practices. Paper C conducts a comprehensive literature analysis of 44 research articles, concentrating on the characteristics of influencers and their audiences, as well as the communication strategies employed by influencers. Collectively, these papers offer marketers and policymakers a comprehensive framework for leveraging influencers to promote sustainable products and services effectively.

This study investigates how Greenfluencers, a subgroup of social media influencers specializing in promoting sustainable lifestyles and raising environmental awareness among their followers, represent sustainability on Instagram. With the assumption of their influence going beyond the commercial sphere, potentially shaping public attitudes and behaviors toward sustainable development, Greenfluencers are considered relevant actors in sustainability communication. This research examines how sustainability is depicted through a qualitative content analysis of posts from ten German-speaking Greenfluencers during August 2023. Drawing on Raworth's "safe and just space for humanity" concept, the study evaluates the content of Greenfluencers' sustainability communication. Results revealed diverse portrayals of sustainability, focusing on environmental issues and individual responsibility. Greenfluencers often overlook the complexity of sustainability, the interconnectedness of social, economic, and environmental aspects, and the systemic causes of sustainability issues. Their content (partly) promotes ‘green’ consumerism through product recommendations and advertisements, overshadowing systemic solutions. Despite these limitations, Greenfluencers have the potential to serve as role models by promoting impactful, sustainable behaviors, such as adopting a plant-based diet. The exploratory nature of the study, its small sample size, and the limited timeframe of the content analysis limit the generalizability of the findings. The study highlights limitations within influencer-driven sustainability communication and underscores the importance of further investigation into the conditions under which social media influencers’ influence can promote sustainable development.