Sea level rise

Definition

Sea level rise refers to the increase in the average level of the world's oceans due to climate change, primarily caused by the melting of ice sheets and glaciers and the thermal expansion of seawater as it warms. This phenomenon has significant implications for coastal communities, ecosystems, and global weather patterns, highlighting the interconnectedness of the climate system and the greenhouse effect.

5 Must Know Facts For Your Next Test

1. Global sea levels have risen by about 8-9 inches (20-23 cm) since the late 19th century, with projections suggesting an increase of up to 3 feet (1 meter) by 2100 if current trends continue.
2. The primary contributors to sea level rise are thermal expansion due to warming oceans and increased melting of ice sheets in Greenland and Antarctica.
3. Rising sea levels can lead to coastal erosion, increased flooding, and the displacement of populations living in low-lying areas.
4. Sea level rise can disrupt ecosystems such as mangroves and wetlands, affecting biodiversity and increasing vulnerability to storms and erosion.
5. It is estimated that by 2050, more than 150 million people could be at risk of displacement due to rising sea levels, particularly in densely populated coastal regions.

Review Questions

• How does the greenhouse effect contribute to sea level rise?
  • The greenhouse effect contributes to sea level rise by increasing global temperatures, which leads to the thermal expansion of seawater and the melting of ice sheets and glaciers. As the atmosphere traps more heat due to increased greenhouse gas emissions, ocean temperatures rise, causing water to expand. This combination results in higher sea levels, which poses significant risks for coastal regions.
• Evaluate the potential impacts of sea level rise on coastal ecosystems and human populations.
  • Sea level rise poses serious threats to coastal ecosystems like mangroves and wetlands, which are critical for biodiversity and act as natural buffers against storm surges. As sea levels rise, these ecosystems can be submerged or degraded, leading to loss of habitat for many species. For human populations, particularly those living in low-lying areas, rising seas can result in flooding, erosion, and displacement, creating urgent challenges for urban planning and disaster preparedness.
• Assess the implications of current projections of sea level rise for future global environmental policies.
  • Current projections of significant sea level rise necessitate urgent global environmental policies aimed at mitigating climate change impacts. Policymakers must address both adaptation strategies for vulnerable coastal communities and aggressive emission reduction targets to limit future warming. The challenges posed by rising seas highlight the need for international cooperation in implementing sustainable practices and investment in resilient infrastructure to protect against inevitable changes that will affect millions worldwide.

Related terms

Greenhouse Effect: The process by which certain gases in the Earth's atmosphere trap heat, leading to a warming effect that contributes to climate change.

Thermal Expansion: The process by which water expands as it warms, contributing to rising sea levels when ocean temperatures increase.

Ice Sheets: Masses of glacial land ice extending more than 50,000 square kilometers, primarily found in Antarctica and Greenland, whose melting is a major contributor to sea level rise.