This dissertation is a contribution to the debate on environmental degradation and development. It focuses on the determinants and macroeconomic effects of environmental degradation. It is structured in two parts. The first part analyses the effects of education and democratic institutions on environmental quality. The first chapter analyses the role of education in environmental quality. No evidence of an effect of education on carbon dioxide emissions. However, this effect depends crucially on the sample of countries according to their levels of development. While the effect remains insignificant in developing countries, education does matter for carbon dioxide emissions in developed ones. Moreover, when controlling for the quality of democratic institutions, the positive effect of education on carbon dioxide emissions is mitigated in developed countries while remaining insignificant in developing ones. The second chapter explores the effect of democratic institutions on environmental quality. We evidence that democratic institutions do have a direct and positive effect on environmental quality. This positive effect is stronger for local pollutants than for global ones. More interestingly, it identifies the indirect channels through which democracy affects environmental degradation. Indeed, by increasing people’s preferences for redistribution and economic policies, democratic institutions have indirect and negative effects on environmental protection through income inequality and investments. In the second part, the dissertation provides two essays on the effects of environmental policies and climate change on development. The third chapter investigates the effects of climatic variability on food security. The results show that climatic variability reduces food security in developing countries. The adverse effect is higher for African sub-Saharan countries than for other developing countries. Second, the negative effect of climatic variability on food security is exacerbated in countries facing conditions of conflict and is high for the countries that are vulnerable to food price shocks. The fourth chapter provides new evidence about the effect of a gap in environmental policies between trading partners on trade flow. While previous papers have used partial measures of environmental regulations (input-Oriented or output-Oriented indicators), we compute an index of a country’s environmental policy. Results suggest that a similarity in environmental policies has no effect on bilateral trade flows. Moreover results do not appear to be conditional on the level of development of the countries trading or on the characteristics of exported goods (manufactured goods and primary commodities).