Climate Change

As a key force in future environmental actions, youth play a crucial role in driving societal transformation. However, the factors influencing youth environmental actions have not been fully validated, and the role of national-level influences is often overlooked. This study aims to identify the factors that are associated with adolescents’ public-sphere and private-sphere environmental actions. Unlike prior studies, which typically use single-level analyses, we simultaneously examine individual, school, and national factors to capture the often-overlooked national context. Using PISA-2018 data on 420,339 adolescents from 66 countries, we used LightGBM and XGBoost to build predictive models. Shapley Additive Explanations (SHAP) were then applied to detect non-linear threshold effects and to quantify each feature’s contribution to environmental action. Results indicate that individual-level factors, such as environmental attitudes, the discussion of international events in school, and critical thinking, are significantly associated with adolescents’ private-sphere environmental actions. Conversely, national-level factors, such as Sustainable Development Goal (SDG) performance and country vulnerability, play a particularly strong role in shaping public-sphere environmental actions. This study underscores the importance of incorporating national-level factors, which have often been under-emphasized in research on youth environmental behavior.

Climate change, driven by unchecked greenhouse gas emissions, has become a pressing global concern. While large-scale anthropogenic activities are primary contributors, individual behaviours also play a significant role in carbon emissions. Carbon Footprint Calculators (CFCs) have emerged as tools to help individuals understand and mitigate their personal carbon footprints. This study presents a comprehensive evaluation of 24 publicly available CFCs, assessing their performance across five key dimensions: methodology, reference data, user inputs, output, and scientific standards. Each CFC has a score that indicates the level of performance, and our findings reveal significant variations in the performance of these CFCs. Notably, Carbon Independent, one of the CFCs, ranked the highest with an average score of 4.54, while the overall mean score for all calculators stood at 3.41, demonstrating its ability to more accurately and comprehensively assess human carbon footprint levels. A heatmap analysis further highlighted strengths and weaknesses across the evaluation dimensions. Additionally, using three hypothetical profiles (Average Household, Large Family, and Urban Single), we observed discrepancies in carbon footprint estimates among the CFCs (standard deviation equals 2.3 tons CO2 Emissions per capita), which means that the calculation design of the carbon footprint calculators is inconsistent. The Chuck Wright Calculator consistently produced the most conservative estimates across all three profiles, while the EPA CFC reported the highest emissions for the urban single profile. Our discussion underscores the potential of CFCs as tools for behavioral change, emphasizing their role in raising individual awareness and driving collective action. The study concludes with recommendations for enhancing the accuracy, transparency, and user-friendliness of CFCs, positioning them as pivotal instruments in the global fight against climate change.