Professional Training in Environmental Education and Education for Sustainable Development: A Comparative Study of Secondary School Teachers’ Perceptions

Environmental Education (EE) and Education for Sustainable Development (ESD) play an important role in promoting sustainability-related knowledge, attitudes, and educational practices. This study examined whether secondary school teachers reporting previous participation in EE/ESD-related professional training differed from those without such training across five dimensions of teachers’ perceptions. A quantitative, cross-sectional study was conducted using questionnaire data from 500 secondary school teachers in Greece, of whom 297 reported previous relevant training and 203 did not. Group differences were examined using the Mann–Whitney U test, with Bonferroni adjustment for five comparisons (α = 0.01). Statistically significant differences were observed for the perceived value and impact of EE/ESD (p < 0.001, r = 0.183), its contribution to students’ social and personal development (p < 0.001, r = 0.202), and pedagogical design and evaluation (p = 0.007, r = 0.121). No statistically significant differences were found for institutional and structural obstacles (p = 0.880) or practical implementation challenges (p = 0.789). The significant differences were associated with small effect sizes. These findings indicate that reported participation in professional training is associated with modest differences in selected dimensions of teachers’ EE/ESD perceptions, without establishing a causal relationship. The results highlight the importance of considering professional development alongside institutional and practical conditions affecting EE/ESD implementation.