Rising Sea Levels

Roland Gehrels*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter


This chapter poses three questions related to sea level rise. The first question is whether sea level IS actually rising. Although the answer depends on one's spatial and temporal perspective, tide-gauge and satellite observations show that sea level has risen at a rate of about 3.2mma-1 since the 1990s when averaged around the globe. The second question pertains to the causes of recent sea level rise. Contributions from the 1990s derive from thermal expansion of ocean water (∼45%), melting of small glaciers and ice caps (∼35%), and melting of Greenland (∼10%) and Antarctica (∼10%), but relative contributions vary with time. Humans have contributed to sea level rise for over a century. In the absence of anthropogenic climate forcing, sea level would have risen ∼0.1m less than observed in the twentieth century. The third question is whether contemporary sea level rise is unusual. Once more, the answer depends on one's timeframe. In the context of the last 5000years, current rates of sea level rise are probably unprecedented.

Original languageEnglish
Title of host publicationClimate Change
Subtitle of host publicationObserved Impacts on Planet Earth: Second Edition
Number of pages12
ISBN (Print)9780444635242
Publication statusPublished - 1 Jan 2015


  • Antarctica
  • Anthropogenic forcing
  • Glaciers
  • Greenland
  • Interglacial
  • IPCC
  • Satellite altimetry
  • Thermal expansion
  • Tide gauge

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