Educational Resources

What is Sea Level Rise?

Sea level rise is the gradual increase in the average level of the Earth’s oceans over time. It occurs when water previously stored on land in glaciers and ice sheets melts and flows into the sea, or when ocean water expands as it warms. This phenomenon has been accelerating in recent decades due to human-driven climate change.

Three Major Causes of Sea Level Rise:

• Thermal Expansion

As global temperatures increase due to greenhouse gas emissions, ocean water warms and expands. Although this process is invisible, it significantly contributes to sea level rise. Even a small increase in temperature leads to noticeable sea level changes because of the vast volume of the oceans.

• Melting of Glaciers and Ice Sheets

Ice stored in land-based glaciers and large ice sheets in Greenland and Antarctica is melting at alarming rates. As this freshwater enters the oceans, it raises sea levels. These melting trends are closely monitored by satellites and climate scientists and are one of the most direct indicators of global warming.

• Loss of Polar Ice and Ice Shelves

In addition to melting, large chunks of ice shelves break off and drift into the ocean. While floating ice doesn’t raise sea levels directly, the collapse of ice shelves allows land-based glaciers to flow into the ocean more quickly, accelerating sea level rise.

Effects of Sea Level Rise – Venice Case Study:

• Increased Tidal Flooding (Acqua Alta)

Venice already experiences regular flooding events known as “acqua alta” (high water). Rising sea levels make these events more frequent and severe, threatening homes, transportation, and daily life.

• Infrastructure Damage

Constant exposure to saltwater degrades historic buildings, bridges, and cultural landmarks. Many of Venice’s foundations are made of wood, which deteriorates faster under persistent flooding.

• Erosion and Loss of Land

Sea level rise leads to the erosion of the Venetian lagoon’s barrier islands and marshlands, further exposing the city to storm surges and high tides.

• Freshwater Contamination

Saltwater can seep into groundwater supplies, making freshwater less available for local use and affecting the delicate balance of the lagoon ecosystem.

• Economic and Social Strain

Flooding impacts tourism—Venice’s main economic engine—and increases costs for residents and local authorities to maintain and protect the city.

Population Size:

• The overall population of the Municipality of Venice is around 250,000.

• The historic center has seen a decline in residents and now has approximately 50,000 people due to tourism pressures and frequent flooding.

 
Racial Demographic Information:

• The majority of residents are ethnic Italians.

• Minority communities include immigrants from Romania, Bangladesh, China, and North Africa, many of whom work in tourism and service industries.

 
Mean Income for the Area:

• The average gross annual household income in Venice is between €29,000 and €31,000.

• Income disparities exist between residents of the historic center and the mainland suburbs like Mestre, where living costs are lower.

 
Infrastructure Breakdown – Residential vs. Commercial:

• Residential Areas: Approximately 65% of the space in Venice is zoned or used for residential housing, although many homes have been converted into tourist accommodations (Airbnbs, hostels, etc.).

• Commercial/Tourist Areas: Around 35% is dedicated to commercial purposes, including shops, restaurants, hotels, museums, and tourist-related businesses.

Public services like water buses (vaporetti), police stations, and schools are increasingly strained by depopulation and frequent flooding.