Sea level rise

Definition

Sea level rise refers to the increasing elevation of the ocean's surface, primarily driven by climate change through two main processes: the melting of glaciers and ice sheets and the thermal expansion of seawater as it warms. This phenomenon has significant implications for coastal regions, ecosystems, and human populations, highlighting the urgency of understanding its causes and effects on the planet's climate systems.

5 Must Know Facts For Your Next Test

1. Global sea levels have risen approximately 8-9 inches since 1880, with projections suggesting a potential increase of 1 to 4 feet by 2100 depending on future emissions scenarios.
2. The melting of Greenland and Antarctic ice sheets is currently one of the largest contributors to sea level rise, accounting for about 20-25% of annual sea level increase.
3. Sea level rise can lead to increased flooding during storm surges, making coastal communities more vulnerable to extreme weather events.
4. The rate of sea level rise is accelerating; satellite data shows that the rate increased from about 1.7 mm per year in the 20th century to about 3.3 mm per year since 1993.
5. Low-lying countries and cities, such as Bangladesh and New Orleans, face existential threats from rising seas, prompting discussions on adaptation strategies like managed retreat and infrastructure improvements.

Review Questions

• How does glacial melting contribute to sea level rise and what are the implications for coastal ecosystems?
  • Glacial melting significantly contributes to sea level rise as glaciers and ice sheets release large volumes of freshwater into the oceans. This influx not only raises sea levels but also alters ocean circulation patterns and salinity, which can impact marine ecosystems. As habitats change due to rising waters, species may be forced to migrate or face extinction, highlighting the interconnectedness of glacial health and coastal biodiversity.
• Discuss how climate models predict future sea level rise and the importance of accurate projections for urban planning.
  • Climate models use various scenarios based on greenhouse gas emissions to predict future sea level rise. These models take into account factors like thermal expansion and glacial melting rates. Accurate projections are crucial for urban planning in coastal areas, as they help policymakers anticipate potential flooding risks and develop infrastructure that can withstand these changes. Planning for future sea levels can mitigate damage and enhance resilience in vulnerable communities.
• Evaluate the long-term socio-economic impacts of sea level rise on global populations and propose potential strategies for mitigation.
  • The long-term socio-economic impacts of sea level rise include displacement of communities, loss of arable land, increased risk of flooding, and economic strain on local governments due to necessary infrastructure improvements. Coastal cities may experience property damage and increased insurance costs as they adapt to rising waters. Strategies for mitigation could involve investing in green infrastructure, enforcing stricter zoning laws for coastal development, and promoting policies that reduce greenhouse gas emissions to slow down climate change effects.

Related terms

Thermal Expansion: The process by which water expands as it warms, contributing to sea level rise.

Glacial Melting: The process of glaciers losing mass due to warming temperatures, which contributes to rising sea levels.

Coastal Erosion: The loss of coastal land due to the action of waves, currents, and rising sea levels, threatening ecosystems and human settlements.