This study investigates how abnormally hot temperatures affect firms’ environmental behavior in China. We find that firms exposed to abnormally hot temperatures participate in more environmental engagement. We also find that this improvement effect is driven mainly by environmental concerns, including public concerns, CEOs, and governments. Our results remain intact after an array of robustness tests. Further analysis shows that the effect of abnormally hot temperatures on corporate environmental engagement is more pronounced in SOEs, heavily polluting firms, and firms located closer to local environmental protection agencies. Moreover, the positive impact of environmental engagement on firm value is stronger when firms are exposed to abnormally hot temperatures. Overall, this study sheds light on the potential stimulation of firms’ environmental actions by global warming, which is yet to be fully understood.

It has been confirmed that sustainable investments contributing to environmental protection can benefit from the deterioration of air pollution, but this influence mechanism has not been fully discussed. This paper proposes a mediation model to study air pollution's influence on green bonds. Theoretically, air pollution raises public environmental awareness and perceptions of physical health risks, leading to increased public concern. Enhanced public concern drives investors' green preference and environmental responsibility, thus expanding green bond demand. Our studies show air pollution is significantly positive related to public concern. Public concern positively links with green bond investment willingness, resulting in increased volatility. The total positive effect of air pollution on green bond is partly absorbed by the effect of public concern. These findings confirm the mediation role of public concern. In addition, major crisis events (e.g., COVID-19) may hinder the mediation process by generating a negative trend and distracting the public.