Cold spell superimposes man-made warming
The Antarctic ice sheet is one of the tipping elements in the climate system and hence of vital importance for our planet’s future under man-made climate change. Even a partial melting of the enormous ice masses of Antarctica would raise sea-levels substantially.
Therefore it is of utmost importance to provide sound knowledge on the extent of anthropogenic warming of the ice-covered continent. A new analysis by German physicists shows that the uncertainties in the temperature trends over Antarctica are larger than previously estimated.
“So far it seemed there were hardly any major natural temperature fluctuations in Antarctica, so almost every rise in temperature was attributed to human influence,” says Armin Bunde of Justus-Liebig-Universität Gießen (JLU).
“Global warming as a result of our greenhouse gas emissions from burning fossil fuels is a fact. However, the human influence on the warming of West Antarctica is much smaller than previously thought. The warming of East Antarctica up to now can even be explained by natural variability alone.” The results of their study are now published in the journal Climate Dynamics.
The melting of Antarctic ice shelves is not only influenced by warming air but also by warming oceans, causing ice loss at the coast. However, as there are no sufficient long-term records for Antarctic ocean warming yet, the study focuses on air temperature trends.
In collaboration with Hans Joachim Schellnhuber of the Potsdam Institute for Climate Impact Research and Christian Franzke of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP) of Hamburg University, the physicists of JLU Armin Bunde and Josef Luderer were able to show that there are major and very persistent temperature fluctuations in Antarctica.
“The climate in Antarctica, just like the global climate, tends to be distinctly persistent by nature – it remains in certain temperature ranges for a long time before it changes. This creates a temporal temperature structure of highs and lows,” explains Christian Franzke.
“A low, i.e. a longer cold period, will be followed by a longer warm period, and this natural warming has to be differentiated from the superimposed anthropogenic warming,” adds Armin Bunde. The scientists did not only analyze data from individual measuring stations but also generated regional averages. The results show a human influence on the warming of West Antarctica, while this influence is weaker than previously thought. However, the warming of Antarctica altogether will likely increase more strongly soon.
For several years temperatures in Antarctica, but also globally, have been increasing less rapidly than in the 1990s. There are a number of reasons for this, e.g. the oceans buffering warmth. The study now published by the German team of scientists shows that man-made global warming has not been pausing - it was temporarily superimposed and therefore hidden by long-term natural climate fluctuations like in Antarctica.
“Our estimates show that we are currently facing a natural cooling period – while temperatures nonetheless rise slowly but inexorably, due to our heating up the atmosphere by emitting greenhouse gas emissions,” explains Hans Joachim Schellnhuber. “At the end of this natural cold spell temperatures will rise even more fiercely. Globally, but also in Antarctica which therefore is in danger of tipping.” In fact, in March 2015 two Antarctic measuring stations registered high-temperature records.
Article: Ludescher, J., Bunde, A., Franzke, C., Schellnhuber, H.J. (2015): Long-term persistence enhances uncertainty about anthropogenic warming of West Antarctica. Climate Dynamics. [DOI: 10.1007/s00382-015-2582-5]
Link to the article: http://link.springer.com/article/10.1007/s00382-015-2582-5
For further information please contact:
PIK press office
Jonas Viering, Sarah Messina
Phone: +49 331 288 2507
Prof. Dr. Armin Bunde
Institut für Theoretische Physik der Justus-Liebig-Universität Gießen (JLU)
Phone: +49 641 99-33375
Mobile: +49 157 33 14 55 55
Caroline Kieke, Public Relations
Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP)
of Hamburg University
Phone: +49 (0) 40 42838 2134
Jonas Viering | Potsdam-Institut für Klimafolgenforschung
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences