Venice Underwater
One of the things that I found really fascinating about Venice was that the entrances to buildings were often feet and sometimes barely inches above the waterline. This made me think about climate change and how the sea levels have been rising lately, and it made me wonder: how long will it be until Venice is underwater?
According to a National Geographic article, the sea level is rising at a rate of approximately 3.2 mm per year. There are a few parts of Venice that are less than 10 cm above sea level, but at least half of the city is less than 140 cm above sea level. At that rate, half of the city would be underwater in about 400 years. So on one hand, it seems like we have several generations to solve this problem.
However, I also learned about an interesting phenomenon in Venice called Acqua Alta, which is when the tides rise and parts of the city flood. The amount of flooding varies based on several factors, but as recently as October 2018, the water rose over 156 cm, submerging over 63% of the city! It can get so bad that one bookstore puts its books in bathtubs and boats to protect them during the Acqua Alta. Museums and other institutions make sure not to keep valuables below the high water line to keep them safe.
Trends have shown that Acqua Altas have been happening more intensely and more frequently in recent years. Add to this the rising sea level - which many scientists are expecting to accelerate as global temperatures rise and glaciers and ice sheets continue to break apart and melt - and Venice is going to be underwater much sooner!
Sample Problems
1. One estimate suggests that the sea may rise at a rate of 4mm per year. At that rate, how long would it be before half of Venice is underwater?
2. Another estimate suggests that the sea may rise at a rate of 6.3mm per year. At that rate, how long would it be before half of Venice is underwater?
3. Another estimate suggests that the sea could rise at a rate as high as 9.4mm per year. At that rate, how long would it be before half of Venice is underwater?