DUGi

Efectes ecològics de la pols sahariana sobre els diferents ecosistemes afectats, el seu abast global i relació amb el canvi climàtic

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@28647

This work is a critical review of the scientific literature on Saharan dust, focusing on its global impacts: ecological, climatic, and health-related, and how they get involved with the current climate change context. The analysis is based on the review of over 200 sources in the field (academic articles, technical reports, digital sources, and books) and allows the identification of the evolution in the study of this natural phenomenon. The review results reveal a scientific consensus on the importance of the Sahara Desert as the main source of atmospheric mineral dust worldwide, focusing on two zones: the Bodélé Depression (Chad) and the West African region (Mauritania, Mali, and Algeria). These areas stand out due to processes that occurred in past periods (Pleistocene and Holocene) and current climatological and geological conditions. The physico‑chemical characterization of the dust is also reviewed, based on its structure and composition (elemental, isotopic, and mineral), which allows determining its atmospheric persistence, transport capacity, and what ecological, climatic, and/or health effects it will have. The review aligns with the main atmospheric routes (Atlantic, Mediterranean, and European‑Eastern), but there is some uncertainty regarding deposition rates in specific regions such as tropical areas and remote oceans, which ultimately complicates the creation of global transport models. Regarding the impacts of Saharan dust, this work focuses on two dust‑receiving regions where its transport has significant but very different effects: the Mediterranean basin and the Amazon basin. In the first region, clear results are shown: recurrent exposure to Saharan‑origin PM10 and PM2.5 particles represents a risk to respiratory and cardiovascular health, whereas, in the second region, these impacts are identified as positive, due to the fertilizing role that Saharan dust plays for Amazonian ecosystems. Finally, the study reflects the scientific debate of recent years regarding the bidirectional relationship between Saharan dust and climate change. While there is consensus on the increase in aridity and land degradation caused by global warming, the role of dust in the global energy balance remains unclear, with some studies attributing it both cooling and warming effects

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