We intend to investigate the role of wetlands in western Amazonia in global climate dynamics during the Miocene, between 23 and 5 million years before the present. During Miocene intervals of global warming and high sea levels, areas of the western Amazon were flooded by the Pebas lacustrine system (with occasional marine incursions). These areas could have acted as carbon sinks (or sources) depending on the prevailing climatic conditions. To test this hypothesis, we will study paleoclimatic records in sedimentary cores that recovered Miocene rocks rich in organic matter in the Solimões Basin (Brazil). In a cyclostratigraphic framework, we will use geochemical techniques to decipher the climate signals recorded by these sedimentary archives. Once the dominant phase relationship between the accumulation of organic carbon in these past wetlands and the regional hydroclimatic context has been deciphered, we will use Earth System models of intermediate complexity to assess the impact of these tropical area processes on the coupled variations between climate and the carbon cycle occurred during the Miocene. As the Miocene was characterized by carbon dioxide (CO2) concentrations comparable (between 450 and 650 parts per million) to projected climate scenarios for the near future, our study can contribute to predicting how the Amazon region will respond to anthropogenic global warming in course.