There has been a sharp increase in sub-national climate mitigation initiatives since the 2000’s. However, the impact of these initiatives on greenhouse gas emissions remains unclear. In this study, we construct a panel combining emissions data from EDGAR, local climate mitigation actions reported to transnational municipal networks, and public opinion data from Eurobarometer for 218 European Union sub-national (NUTS-2) regions for the years 2010-2019. We use this dataset to test if public attitudes toward climate change influence the provision of local climate actions, and whether these actions, in turn, contribute to emission reductions. Our analysis finds a positive association between local climate action and local public sentiments, namely, climate change concern, economic optimism linked to policies, and perceived responsibility of the government. We also conclude that the adoption of local actions significantly reduces GHG emissions per capita in these regions in the long run. Finally, local actions are especially effective in achieving emission reductions in stringent national climate policy contexts, but local-policy makers tend to provide more climate actions if national policies are lax.