Sea level rise

Definition

Sea level rise refers to the increase in the average level of the world's oceans due to various factors, primarily linked to climate change. This phenomenon is driven by the thermal expansion of seawater as it warms and the melting of glaciers and polar ice sheets, contributing to the overall volume of ocean water. As sea levels rise, coastal areas face increased flooding, erosion, and saltwater intrusion, posing significant risks to ecosystems and human settlements.

5 Must Know Facts For Your Next Test

1. Sea levels have risen about 8 to 9 inches (20 to 23 cm) since 1880, with accelerated rates observed in recent decades.
2. The Intergovernmental Panel on Climate Change (IPCC) predicts that sea levels could rise by 1 to 4 feet (0.3 to 1.2 meters) by the end of the century if current trends continue.
3. Low-lying coastal cities such as Miami, New Orleans, and Jakarta are particularly vulnerable to flooding caused by rising sea levels.
4. Melting ice from Greenland and Antarctica contributes significantly to global sea level rise, accounting for about one-third of the observed increase.
5. Rising sea levels can lead to saltwater intrusion into freshwater aquifers, threatening drinking water supplies and agricultural irrigation.

Review Questions

• How do thermal expansion and glacial melt contribute to sea level rise?
  • Thermal expansion occurs when seawater warms up, causing it to take up more space, which contributes significantly to rising sea levels. Glacial melt refers to the melting of ice from glaciers and ice sheets, which adds more water to the oceans. Together, these two processes drive the increase in average sea levels globally, posing risks to coastal communities and ecosystems.
• Discuss the implications of sea level rise for coastal cities and ecosystems.
  • Sea level rise has serious implications for coastal cities and ecosystems. Increased flooding can lead to property damage, displacement of residents, and economic losses in urban areas. Additionally, coastal ecosystems such as wetlands and mangroves are threatened by erosion and saltwater intrusion, which can disrupt habitats for wildlife. These changes highlight the urgent need for adaptive strategies in urban planning and environmental conservation.
• Evaluate the potential long-term impacts of unchecked sea level rise on global populations and economies.
  • Unchecked sea level rise could lead to catastrophic long-term impacts on global populations and economies. Millions of people living in low-lying areas may be displaced due to flooding or loss of land, leading to climate refugees and increased pressure on urban centers. Economically, rising sea levels can damage infrastructure and reduce property values in vulnerable areas, straining local economies. Furthermore, agricultural systems may suffer from salinization of soil and water sources, threatening food security on a broader scale.

Related terms

thermal expansion:

The process by which water expands as it warms, contributing to rising sea levels.

glacial melt: The process of ice melting from glaciers and ice sheets, releasing freshwater into the oceans and further contributing to sea level rise.

coastal erosion: The loss of coastal land due to the action of waves, currents, tides, and rising sea levels, leading to the displacement of habitats and communities.