What is the difference between "sea level rise" and "sea level change"?

"Sea level change" and "sea level rise" are terms often used in discussions about climate and oceanography, but they have distinct meanings. Note, the movement of land can contribute to "relative" versions of both of these terms, but here the definitions only apply to the movement of the ocean.

Sea Level Change

• Definition: This term encompasses any variation in the level of the sea.
• Includes: Both increases and decreases in sea levels.
• Causes: Multiple factors such as:
  • Thermal Expansion: Water expands as it warms.
  • Melting Ice: Glaciers and ice sheets melting add water to the oceans.
  • Ocean Circulation Changes: Shifts in ocean currents can redistribute water masses.
  • Atmospheric Pressure Changes: High or low pressure can raise or lower sea levels.
  • Tides and storms: Short-term ups-and-downs over periods of hours to days.
• Scope: Short-term (daily tides, seasonal changes) and long-term (decadal to millennial scales).

Sea Level Rise

• Definition: A specific type of sea level change referring to a long-term increase in the average level of the world's oceans.
• Includes: Long-term increase in sea level.
• Causes: Primarily due to:
  • Thermal Expansion: Water expands as it warms.
  • Melting Ice: Glaciers and ice sheets melting add water to the oceans.
• Scope: Typically assessed over longer time frames (decades to centuries).

Summary

• Sea Level Change: Broader term, includes both increases and decreases, affected by various factors.
• Sea Level Rise: Narrower term, specifically refers to the long-term increase in sea levels due to global warming.