Climate change
Sea level is rising by up to 1.3 metres
The sea level by the year 2100 the world around 0.5 to 1.3 meters rise if CO2 emissions are not quickly reduced. A new study calls for Action and now provides data for the coastal protection.
Meereshochwasser in the centre of Venice
Since the end of the 19th century. Century increased the average temperature on the earth by one degree Celsius, at the same time, sea levels rose by about 20 centimeters. Greenhouse gases, as hitherto, continue to be ejected, the sea level worldwide is likely to be a further 50 to 130 centimeters by the end of this century increase. This is the result of a recently published study in the scientific Journal “Proceedings” of the US Academy of Sciences.
“With all of the already emitted greenhouse gases in the atmosphere, we can the sea-level rise will not stop, but by Stopping the use of fossil fuels or significantly limit,” says author Anders Levermann from the Potsdam Institute for climate impact research (PIK) and lead author of the Weltklimareport (IPCC). According to the researchers ‘ calculations, would be in terms of limiting global warming to below two degrees, the sea level in comparison to today, still around 20 to 60 centimetres by the end of the century rise.
Particularly affected are the Netherlands, Bangladesh, Venice, New York, Tokyo, Syndey, Mumbai and London.
The challenge for coastal protection
With the study, and a freely accessible, computer simulations provide the authors, scientists, Politicians and insurers a tool for coastal protection and the prevention. “We want to provide the planners with the necessary background information for their adaptation planning. This is important for the construction of dikes, for insurance concepts and for the long-term planning of settlements,” says Levermann.
Even when limiting global warming to below two degrees to succeed and thus the sea level by 20 to 60 cm until the end of this century increases, according to the authors, the challenges for the global coastal defense immensely. “Even such a reduced increase would be quite a challenge, but less expensive than the adaptation to unmitigated sea-level rise in some regions of the world, even completely would be impossible,” says Levermann. “If the world is the greatest loss and damage want to avoid, we must now quickly follow the path to the UN climate change conference in Paris a few weeks ago has agreed.”
The Pacific island Tuvalu is the rise in sea levels particularly affected. More and more often there are Floods.
Help for risk assessment
The computer simulation on sea level rise takes into account the contribution of melting glacier, the mass loss of the ice sheets at the poles and thermal expansion of warmer seawater, in accordance with the laws of physics, taking up more space. “Our tool is designed so that it both to the observations of the past as well as to the long-term physical processes of the different elements of the earth system”, says lead author Matthias Mengel from the SPADES. “Above all, however, our calculation method to quickly and easily reproducible, so that many Simulationsdurchläufe are possible, the probabilities of sea level rise to be calculated.”
The Software makes the risks now better estimate. “Küstenplaner need a reasonable estimate for the worst as well as for the cheapest possible case, to the opportunities and costs to weigh,” explains co-author Ben Marzeion from the University of Bremen. “The best available science will now be merged to a common uncertainty ranges in future sea-level rise to be determined and a further acceleration of sea level rise by reducing greenhouse gas emissions to prevent that.”
Many people in Bangladesh is higher Meerespegel meeting. A corresponding Küstenschütz is difficult.
Sea-level rise like never before
The ‘Proceedings” published yet another study on the sea level rise. Examined was the increase in the past. “In the past thousands of years, the sea level is never increased more rapidly than in the last century,” says author Stefan Rahmstorf of PIK. The study confirms previous assumptions and provides, according to the climate scientists an unprecedented robustness. “The data confirm once again, how unusual our age of the global warming caused by greenhouse gas emissions. And they show that the sea level rise as one of the most dangerous effects of climate change already in full swing.”