Sea level rise

Definition

Sea level rise refers to the increase in the average level of the world's oceans due to various factors, including melting ice sheets, glaciers, and thermal expansion of seawater as it warms. This phenomenon has far-reaching implications for coastal ecosystems, human populations, and global climate patterns, making it a critical aspect of understanding climate change and its effects.

5 Must Know Facts For Your Next Test

1. Sea level has been rising at an average rate of about 3.3 millimeters per year since the early 1990s, which is faster than the average rate observed throughout the 20th century.
2. The primary contributors to sea level rise are the melting of polar ice sheets in Greenland and Antarctica and the thermal expansion of seawater as global temperatures increase.
3. Coastal cities are particularly vulnerable to sea level rise, with many facing increased flooding and damage from storm surges as water levels continue to rise.
4. Rising sea levels can lead to saltwater intrusion into freshwater aquifers, threatening drinking water supplies and agriculture in coastal regions.
5. Predictions indicate that if greenhouse gas emissions continue unabated, global sea levels could rise by 1 to 2 meters by the end of the century, significantly impacting coastal communities.

Review Questions

• How does thermal expansion contribute to sea level rise and what implications does this have for coastal ecosystems?
  • Thermal expansion occurs when water heats up and occupies more space, which directly contributes to sea level rise. As global temperatures increase due to climate change, the oceans warm up, leading to this expansion. This rise in sea levels can inundate coastal habitats such as wetlands and mangroves, disrupting ecosystems that rely on these areas for shelter and breeding.
• Evaluate how human activities contribute to the factors causing sea level rise and discuss potential mitigation strategies.
  • Human activities such as burning fossil fuels increase greenhouse gas emissions, leading to global warming. This causes polar ice melt and thermal expansion of seawater. Mitigation strategies include reducing carbon emissions through renewable energy sources, enhancing energy efficiency, and implementing coastal management practices to protect vulnerable areas. These efforts are crucial in slowing down the rate of sea level rise.
• Synthesize the long-term social and economic impacts of sea level rise on urban planning in coastal cities.
  • Long-term impacts of sea level rise on urban planning include increased flooding risk, displacement of populations, and strain on infrastructure such as roads and sewage systems. Coastal cities must adapt by investing in resilient infrastructure like seawalls or elevated buildings while also considering relocation plans for communities most at risk. Failure to address these challenges could lead to significant economic losses and exacerbate social inequalities as vulnerable populations bear the brunt of these changes.

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, adding freshwater to the oceans and contributing to sea level rise.

coastal erosion: The loss of land along coastlines due to wave action, currents, tides, and rising sea levels.