Many countries are part of multiple international air-pollution agreements that interact with each other given that a single source of emissions is typically composed of several pollutants. This paper studies the e ect on carbon dioxide emissions of the various agreements that follow the Long-Range Transboundary Air-Pollution (LRTAP) Convention and that are related to acid rain problems. The analysis is based on a panel dataset of 150 countries over the period 1970 - 2008. We show that ratifying each additional treaty has a significant and negative impact on the level of CO2 emissions, even if they are not specically targeted toward carbon emissions. Our ndings can be explained by (1) the more local nature of pollutants covered (2) the relative ease to implement LRTAP treaties. To deal with an eventual reverse causality problem, we instrument the decision to ratify treaties by the status of the death penalty in each country.