Sea level rise

Definition

Sea level rise refers to the increase in the average level of the world's oceans due to the melting of ice sheets and glaciers, as well as the thermal expansion of seawater as it warms. This phenomenon is primarily driven by climate change and global warming, which cause more heat to be trapped in the atmosphere and lead to significant changes in ocean dynamics. Understanding sea level rise is crucial for assessing the impact of climate change on coastal communities, ecosystems, and infrastructure.

5 Must Know Facts For Your Next Test

1. Global sea levels have risen about 8 inches since 1880, with rates accelerating in recent decades due to climate change.
2. Melting ice from Greenland and Antarctica is a significant contributor to sea level rise, with projections suggesting that continued warming could lead to several feet of rise this century.
3. Thermal expansion accounts for roughly half of the observed sea level rise, as warmer water occupies more space than colder water.
4. Coastal cities like Miami and New Orleans are particularly vulnerable to flooding as a result of sea level rise, leading to increased investment in adaptation strategies.
5. Rising sea levels pose a threat to ecosystems such as wetlands and mangroves, which provide essential services like storm protection and carbon storage.

Review Questions

• How does thermal expansion contribute to sea level rise, and what role does it play compared to glacial melt?
  • Thermal expansion contributes significantly to sea level rise by causing seawater to expand as it warms. This process accounts for about half of the total increase in ocean levels. In comparison, glacial melt from ice sheets and glaciers also adds water to the oceans but has been accelerating due to higher global temperatures. Together, both thermal expansion and glacial melt are critical factors driving current rates of sea level rise.
• Evaluate the potential impacts of rising sea levels on coastal communities and ecosystems.
  • Rising sea levels can have devastating effects on coastal communities, leading to increased flooding, property damage, and displacement of residents. Economically vital areas may face heightened risks, resulting in costly infrastructure damage and loss of livelihoods. Ecosystems such as wetlands and mangroves may also be at risk, as rising waters can drown these vital habitats, disrupt wildlife, and reduce their ability to protect shorelines from storms.
• Assess the long-term implications of unchecked sea level rise due to climate change on global geopolitics and economics.
  • Unchecked sea level rise poses serious long-term implications for global geopolitics and economics. As low-lying nations face existential threats from rising waters, there may be increased tensions over migration as people are displaced from their homes. Additionally, economic impacts could include substantial costs associated with rebuilding infrastructure or relocating populations. Countries that are less equipped to deal with these changes may struggle with political instability, further exacerbating global inequities as wealthier nations may be better able to adapt or mitigate these challenges.

Related terms

thermal expansion: The increase in water volume caused by the warming of ocean water, contributing to rising sea levels.

glacial melt: The process of glaciers and ice sheets losing mass due to increased temperatures, contributing to rising sea levels.

coastal erosion:

The loss of land along coastlines due to the action of waves, currents, and rising sea levels, impacting human settlements and natural habitats.