Paulo Baganha, researcher at CESAM/DGEO and assistant researcher at the University of Aveiro, was the guest speaker at the webinar “Climate Change and Coastal Risks”, part of the In Defense of the Ocean project — an initiative promoted by Estudo Autónomo and Escola Azul, aimed at raising awareness among school communities and the general public about today’s coastal challenges.
During his presentation, the researcher addressed the evolution of climate and mean sea level throughout geological time, placing current climate change within the broader context of Earth’s major natural cycles, such as the Milankovitch cycles, solar activity variability, and global tectonic processes. From this long-term perspective, Paulo Baganha emphasized the importance of understanding recent changes, which are heavily influenced by human activity — particularly the significant increase in atmospheric carbon dioxide concentrations since the pre-industrial era.
The webinar gave special attention to the consequences of sea level rise on coastal systems, especially sandy, low-lying shorelines that are most vulnerable to erosion, storm surges, and coastal flooding. Using observational data — such as the historical sea level record from the Cascais tide gauge — the researcher highlighted the accelerating trend of sea level rise in recent decades and explained how this phenomenon contributes to shoreline retreat, potentially reaching several tens of meters over the course of a century.
In the context of the Portuguese coastline, Paulo Baganha presented specific examples of areas particularly affected by coastal erosion, including stretches between Cortegaça and Furadouro, Costa Nova, southern Figueira da Foz, and Costa da Caparica. He also stressed that beyond sea level rise, sediment deficit — strongly linked to river regulation through dams and changes in fluvial dynamics — is currently one of the main factors exacerbating coastal erosion in Portugal.
The session also included a reflection on coastal risk management and adaptation strategies, ranging from accepting the natural evolution of the shoreline in uninhabited areas to implementing prevention, accommodation, and protection measures. These include planned relocation of infrastructure, adapting buildings to coastal dynamics, and engineering works or artificial beach nourishment.
The webinar concluded with a Q&A session, where topics such as the impact of inland decisions on coastal erosion, construction in coastal zones, climate change denial, and the importance of the ocean as a “source of life” — a phrase chosen by the researcher to express his personal view of the ocean — were discussed.
Link to the full webinar available here.
Image credit: 90 segundos de ciência