We use cookies to imporve your experience. By using our site, you consent to our cookie policy Learn more
arrow arrow_up breadcrumb-chevron-right breadcrumb-home dropdown-arrow-down loader GALogoWUNEP GALogo2018 GALogo2019 menu read-more-plus rrss-email rrss-facebook rrss-flickr rrss-instagram rrss-linkedin rrss-twitter rrss-vimeo rrss-youtube rrss_google_plus rrss_skype rrss_web pdf search share Completed In Process Ideas In Develpment Toogle Toogle Thumbnail View List View play close filter-collapse filter edit media_photo_library media_video_library graphics pictures videos collections next

Sea level rise due, past and scenarios due to global warming

Over the last 100 years, the global sea level has risen by about 10 to 25 cm. Sea level change is difficult to measure. Relative sea level changes have been derived mainly from tide-gauge data. In the conventional tide-gauge system, the sea level is measured relative to a land-based tide-gauge benchmark. The major problem is that the land experiences vertical movements (e.g. from isostatic effects, neotectonism, and sedimentation), and these get incorporated into the measurements. However, improved methods of filtering out the effects of long-term vertical land movements, as well as a greater reliance on the longest tide-gauge records for estimating trends, have provided greater confidence that the volume of ocean water has indeed been increasing, causing the sea level to rise within the given range. It is likely that much of the rise in sea level has been related to the concurrent rise in global temperature over the last 100 years. On this time scale, the warming and the consequent thermal expansion of the oceans may account for about 2-7 cm of the observed sea level rise, while the observed retreat of glaciers and ice caps may account for about 2-5 cm. Other factors are more difficult to quantify. The rate of observed sea level rise suggests that there has been a net positive contribution from the huge ice sheets of Greenland and Antarctica, but observations of the ice sheets do not yet allow meaningful quantitative estimates of their separate contributions. The ice sheets remain a major source of uncertainty in accounting for past changes in sea level because of insufficient data about these ice sheets over the last 100 years.

Year: 2005

From collection: Vital Climate Graphics

Cartographer: Philippe Rekacewicz, UNEP/GRID-Arendal

Graphics included in same album

View all media

Publications it appears in

View all publications