This is due to a change in ocean-atmosphere heat exchange, scientists of the Potsdam Institute for Climate Impact Research discovered. Heat in lower oceanic layers is trapped by a cooling of upper layers, says a study which is about to be published in the journal Earth System Dynamics.
Even if it would work to cool down the planet by extracting CO2 from the atmosphere, according to the calculations this cooling would be ten times slower than the currently observed temperature rise by greenhouse gases. Steric sea level rise under this scenario would continue for 200 years after the peak in surface air temperatures.
At the climate summit in Cancún, Mexico, it is being debated whether and how climate change of more than two degrees compared to the preindustrial age can be prevented. Pledges by many states to reduce their emissions of CO2 would still lead to an increase of global mean temperatures by 3 to 4 degrees. One year ago, in Copenhagen, after pressure by mainly small island states it was decided that a more ambitious scenario of emission reduction should also be investigated, with a 1.5 degrees limit. Research on this up to now has been sparse. PIK researchers have now simulated several scenarios with high-performance computers.
“The good news is that a limitation of global warming really could be achieved if emissions declined after the year 2015 and if from 2070 considerable amounts of CO2 would be extracted from the atmosphere,“ says lead-author Jacob Schewe. To achieve this, however, fossil fuels would probably have to be substituted by the massive use of biomass plus carbon capture and storage. These two technologies imply risks. But the bad news is, Schewe says: “Even a mean temperature rise of less than two degrees would have far-reaching consequences – though less severe ones than in the case of stronger global warming.“
Thermal oceanic expansion alone would yield, under the 1.5 degrees scenario, a mean sea level rise of 30 centimeters in 2250. “This would already have serious effects on many coastal regions,“ says Anders Levermann, co-author and professor of dynamics of the climate system. “If we just keep on emitting greenhouse gases, in a business-as-usual scenario, steric sea level rise wouldn't stop even in 2500, resulting in a mean sea level rise of 200 centimeters.“ In addition to this, there would be contributions to sea level rise from melting ice sheets. Monsoon rainfall in Asia could also be considerably affected, even under the 1.5 degrees scenario. All of this is significant for the issue of adaptation to climate change, which is on the agenda in Cancún.
Most relevant are changes of temperature in the oceans, the simulation run by the PIK researchers shows. In the northern Atlantic, for instance, there could be abnormal warming for a long time. This would be provoked not just by the known inertia but by the newly discovered, still stronger mechanism whereby cooling on the surface interferes with regular ocean-atmosphere heat exchange. This could affect marine ecosystems. The ice-shelves of Antarctica could melt. And prolonged deep ocean warming could trigger the dissociation of methane hydrates in ocean sediments and thereby release additional amounts of greenhouse gas into the atmosphere.
Link: http://www.pik-potsdam.de/%7Eanders/publications/schewe_levermann10b.pdfFor further information please contact the PIK press office:
Jonas Viering | PIK Potsdam
Early organic carbon got deep burial in mantle
25.04.2017 | Rice University
New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences