That sea level is rising faster than expected could mean that the Intergovernmental Panel on Climate Change's (IPCC) sea-level rise projections for the future may be biased low as well, their results suggest.
Sea-level rise potentially affects millions of people all around the world in coastal areas as well as megacities like Tokyo.
"Global temperature continues to rise at the rate that was projected in the last two IPCC Reports. This shows again that global warming has not slowed down or is lagging behind the projections," Rahmstorf says. Five global land and ocean temperature series were averaged and compared to IPCC projections by the scientists from Potsdam, the Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (LEGOS) in France and the US based Tempo Analytics. To allow for a more accurate comparison with projections, the scientists accounted for short-term temperature variations due to El Niño events, solar variability and volcanic eruptions. The results confirm that global warming, which was predicted by scientists in the 1960s and 1970s as a consequence of increasing greenhouse concentrations, continues unabated at a rate of 0.16 °C per decade and follows IPCC projections closely.
Data of sea-level rise provided a different picture though. The oceans are rising 60 per cent faster than the IPCC's latest best estimates, according to the new research. The researchers compared those estimates to satellite data of observed sea-level rise. "Satellites have a much better coverage of the globe than tide gauges and are able to measure much more accurately by using radar waves and their reflection from the sea surface," Anny Cazenave from LEGOS explains. While the IPCC projected sea-level rise to be at a rate of 2 mm per year, satellite data recorded a rate of 3.2 mm per year. The increased rate of sea-level rise is unlikely to be caused by a temporary episode of ice discharge from the ice sheets in Greenland or Antarctica or other internal variabilities in the climate system, according to the study, because it correlates very well with the increase in global temperature.
"In contrast to the physics of global warming itself, sea-level rise is much more complex," Rahmstorf says. "To improve future projections it is very important to keep track of how well past projections match observational data." Rahmstorf stresses that "the new findings highlight that the IPCC is far from being alarmist and in fact in some cases rather underestimates possible risks."
Potsdam Institute for Climate Impact Research (PIK): http://www.pik-potsdam.de
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Augmented and virtual reality games may help crack the code of getting humans to do something about the environment
Drones detect far more ocean garbage than previously known, including debris from Japan's 2011 tsunami
Scientist estimates that eating a pound of beef causes more greenhouse warming than burning a gallon of gasoline
May was the hottest on record, too
Less rain and snow due to climate change will impact plants and insects that birds rely on
SALT LAKE CITY (Reuters) - A pair of California condors have successfully hatched a chick in the rocky peaks of Utah's Zion National Park, biologists have said, in what is believed to be the first birth of its kind in the Western state.
They're vanishing fast, but the world is paying scant attention
Finding an invasive python in the wild is difficult, which is why you need a volunteer army
Program can distinguish among hundreds of species in recorded birdsongs
Giant excavators at Germany's Hambach mine are churning out eye-watering amounts of lignite – aka brown coal, the dirtiest fossil fuel out there