The Uruguayan government states in the National Adaptation Plan for the Coastal Zone in the Face of Climate Variability and Change
that "the level of vulnerability of coastal resources is high, considering changes in rainfall, discharges from the tributaries of the Río de la Plata, modification of wind patterns and mean sea level."Global sea level has risen between 21 and 24 centimeters on average since 1880, according to the US. National Oceanic and Atmospheric Administration (NOAA)
and is rising twice as fast today as it did 30 years ago: from 2.1 millimeters per year between 1993 and 2002, to 4.4 millimeters per year between 2013 and 2022, according to the World Meteorological Organization
(WMO). On the Montevideo coast the sea level rose 11 centimeters since 1902 -at a rate of 1.1 millimeter per year- and on the Rocha coast more than 20 centimeters since 1955 -at a rate of 1.4 millimeter per year- according to research on sea level trends in Uruguay carried out by oceanographer José Verocai et al., published in the scientific journal 'International Journal of Marine Science'. In addition, the national benchmark study conducted in 2019 by the Institute of Environmental Hydraulics of the University of Cantabria (Instituto de Hidráulica Ambiental de la Universidad de Cantabria) for the Uruguayan Ministry of the Environment, estimates that the sea in Uruguay will rise between 42 and 58 centimeters by 2100.
Precipitations and winds have also increased and projections indicate that they will continue to increase towards the end of the 21st century. Average annual precipitation increased 10-20% between 1961 and 2017, according to the study Climate Analysis
and Scenarios of Climate Change and Variability in Uruguay (Análisis del clima y escenarios de cambio y variabilidad climática en Uruguay) of the Department of Atmospheric Sciences of the Institute of Physics of the School of Sciences. The research estimates that by 2100 cumulative rainfall will increase 20-30% during autumn and summer, and there will be a greater number of extreme events.
Wind speeds during extreme events on the coast during the winter intensified 10-20%, according to the same study. By 2100, these events are expected to increase in winter in the coastal zone, with speeds of up to 200 km per hour in short periods and 100 km per hour in long periods.
But not all the changes in the environment can be explained by these climate change variables, the main drivers of which are beyond the reach of national policy. "Human intervention degrades the environment much more and exposes vulnerable populations even more than the variation of 1 millimeter per year in sea level," explains Silvia Marcomini, PhD in Geology from the University of Buenos Aires. Marcomini has dedicated herself to research in environmental geology, particularly in coastal areas, and explained for this report that, in addition to taking into account climate variability and change, human action and local public policies must also be considered.
For the researcher, climate change cannot be an excuse to mask unsound public policies. “I am concerned about this because decision makers use climate change to avoid doing other things. Behind climate change they hide the environmental problems of pollution and overexploitation of resources that we are having in these coastal areas, such as sewage drains, garbage dumps, urbanizations, mega-developments that disregard the environmental balance altogether."
Therefore, as a consequence of human action and climate change, Montevideo's geography will be different from what it is today. The analysis of the flood lines carried out by the Ministry of the Environment shows, for the most extreme climate change scenario, that Uruguay's capital will lose -by 2100 and in the face of extreme events- approximately 10% of its surface area. At present, it is 200.7 square kilometers.
According to this study, the floods will impact the city's infrastructure and, above all, they will affect Montevideo's population unequally.