What global sea-level change is caused by overall changes in water volume and land ice, affecting coastlines worldwide?

• A. Eustatic Change
• B. Fjord
• C. Estuary
• D. Foreshore

Answer: (A)

Eustatic change is the global sea-level change caused by variations in ocean water volume and the amount of land ice. When ice sheets and glaciers melt, water returns to the oceans, raising sea level worldwide; when ice grows or water is stored on land, sea level falls. Thermal expansion from warming also increases ocean volume, contributing to higher global sea levels. This global nature distinguishes it from local or landform features like fjords, estuaries, or foreshore, which are not about worldwide changes in sea level.