May 30, 2016

Internal variability versus anthropogenic forcing on sea level and its components

by
Marta Marcos, Ben Marzeion, Sönke Dangendorf, Aimée B. A. Slangen, Hindumathi Palanisamy, Luciana Fenoglio-Marc
,
Surveys in Geophysics
  • Reviews and updates detection and attribution studies in sea level and its major contributors during the past decades
  • Tide gauge records reveal that the observed twentieth-century global and regional sea level rise is out of the bounds of its natural variability, evidencing thus a human fingerprint in the reported trends
  • Finds that the signal varies regionally, and it partly depends on the magnitude of the background variability
  • Finds that the human fingerprint is also manifested in the contributors of sea level for which observations are available, namely ocean thermal expansion and glaciers’ mass loss, which dominated the global sea level rise over the twentieth century
  • States that attribution studies provide evidence that the trends in both components are clearly dominated by anthropogenic forcing over the second half of the twentieth century
  • States that, in the earlier decades, there is a lack of observations hampering an improved attribution of causes to the observed sea level rise
  • Concludes that at certain locations along the coast, the human influence is exacerbated by local coastal activities that induce land subsidence and increase the risk of sea level-related hazards