El rise and fall of sea level is reshaping coastlines, altering ecosystems, and posing economic, environmental, and social challenges on a global scale. The latest research shows that these changes can occur in stages or even abruptly, depending on the behavior of polar glaciers and regional climatic conditions. Phenomena such as the melting of ice in Greenland or Antarctica not only contribute to the rising sea levels, but also generate unexpected fluctuations that affect both urban and rural environments.
Some regions are beginning to experience the consequences directly. Coastal communities in Latin America, Europe, and Asia are seeing the sea invade land, erode infrastructure, and force the displacement of families.. On the other hand, in places like the Caspian Sea, the lowering of the water level This is leading to the emergence of new geographical formations, such as islands, and bringing with it new threats to the biodiversity and economic balance of the area.
Historical changes and signs of the past
The most complete records on the sea level go back to more than two centuries back, with modern satellite technologies available since the 1990s. By combining both records, scientists have identified a clear trend: Global sea level is rising, and the pace is accelerating Each year. An illuminating example comes from the analysis of coral fossils in the Indian Ocean, where the behavior of sea level during the Last Interglacial, more than 120.000 years ago, has been reconstructed. The results show that, due to the uneven melting of ice masses in both hemispheres, the sea level rose in several stages, interspersed with sudden drops that produced complex sequences in reef growth.
During that period, a increase of up to 7,4 meters above the current levelSome experts believe that We could be facing the possibility of global increases exceeding 10 meters., if the current rate of warming continues. Antarctica, especially, may be more sensitive to heat than previously estimated.
Effects on local environments: communities at risk
La Venezuelan Guajira is a recent example of the direct impact of rising sea levels: coastal erosion and saltwater intrusion are changing the lives of indigenous communities, forcing the displacement of families and threatening vital resources. In Spain, specifically in EuskadiSea levels have risen more than 20 centimeters in the last two centuries, accompanied by an increase in adverse weather events, such as heat waves and intense rainfall. Experts warn of the importance of adaptation and the creation of resilient infrastructure to address these challenges, highlighting the role of regional laws and investment in climate observation networks.
Economic losses linked to extreme weather events in Europe already exceed €560.000 billion between 1980 and 2021. Furthermore, if this global warming scenario continues, the economic impact will continue to grow, affecting infrastructure, agriculture and the daily lives of citizens.
The drop in sea level and the emergence of new islands
The case of Caspian Sea illustrates that sea level variations do not always imply a rise. The retreat of its waters, attributed both to the reduction in the flow of the rivers that feed it and to the increase in evaporation due to global warming, has exposed new islands and sandbanksRussian and Azerbaijani scientists have documented how, in recent decades, the sea surface has been shrinking and regional geography has changed abruptly. It is estimated that, if current trends continue, sea levels could drop more than 20 meters before the end of the XNUMXst century, jeopardizing biodiversity and generating geopolitical and environmental challenges.
These changes also affect species that depend on coastal ecosystems and the exploitation of strategic resources, such as oil and gas. The emergence of new islands due to the lowering of the sea level highlights the urgency of implementing adaptation measures and carry out exhaustive scientific monitoring.
Study and adaptation tools
Thanks to the use of technologies such as satellite altimetry and historical tide gauge recordsScientists can anticipate trends and propose adaptation actions. Institutions like NASA generate data that allow for risk assessments in cities and coasts, as well as quantifying the population and assets under threat. Furthermore, mangrove distribution maps, water quality monitoring, and analysis of glacier evolution strengthen the capacity of communities and governments to adopt preventive and adaptive policies, essential for addressing current and future climate challenges.
Sea level rise is a multifactorial and complex phenomenon that responds to multiple factors, from global warming to local and regional conditions. From land loss in the Caribbean to increased flooding in the Basque Country to the emergence of islands in the Caspian Sea, the ability to anticipate and respond to these changes will be crucial to the survival and sustainability of many coastal societies.
