1. Sources of CO2 acidification in aquatic ecosystems, natural versus anthropogenic2. Risk Assessment of CO2 acidification in aquatic ecosystems based on a weight of evidence approach3. Using the Chemical Line of Evidences to address the acidification4. The use of toxicity tests to address the impact of acidification in aquatic ecosystems5. Addressing the effects of CO2 acidification under 'in situ' conditions. Laboratory against field surveys6. Integrating causes and effects in CO2 acidification7. Legal and Economical consequences of anthropogenic CO2 acidification8. The consequence of CO2 acidification in the harmful effects of emergent contaminants: illicit drugs, microplastics, etc9. Plasticity, adaptation and other mechanisms using by organisms to live with CO2 acidification in aquatic ecosystems10. Advance in studies of CO2 acidification in fresh water ecosystems: sources, impacts, etc.11. Estimating the impact of CO2 acidification in a very sensible and complex system: The Cenotes, Yucatán, Mexico