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“In other words, no tipping point is likely to devour what’s left of the Arctic summer sea ice.
The model features no bifurcation, nor increased rate of retreat, as the ice disappears.For example, even in a warming world, there’s still a one-in-three chance that any seven-year period would see no sea ice loss, such as in 2007-2013, the new analysis shows.And the chaotic nature of weather can also occasionally produce sea ice loss as rapid as that seen in 2001-2007, even though the long-term trend is slower.Nevertheless, the impact of anthropognic forcing on the long-term sea ice evolution is clear, with an average loss of 3 m The practical consequences of climate change challenge society to formulate responses that are more suited to achieving long-term objectives, even if those responses have to be made in the face of uncertainty.Here we present methods to detect when climate predictions are failing to capture the system dynamics.Wagner and Eisenman’s research was co-funded by the Office of Naval Research (ONR) and by the National Science Foundation. “The Navy has broad interest in the evolution of the Arctic,” said the ONR’s Frank Herr.
“Sea ice dynamics are a critical component of the changing environmental picture.
Nonetheless, the autocorrelation of summer sea ice area is found to increase in a global warming scenario. A simple physical mechanism is proposed to explain the occurrence of increasing autocorrelation but not variance when there is no approaching bifurcation.
Additionally, a similar mechanism is shown to allow an increase in both indicators with no physically attainable bifurcation.
For space constraints, the focus was only on September sea ice coverage as this is the month with the strongest observed trends.
The discussion can be summarized as follows:- On decadal time scales, internal climate variability can cause a substantial acceleration or temporary recovery of the sea ice cover that renders the evaluation of individual model simulations based on their short-term trends impossible.- On longer time scales, internal variability causes a substantial spread in possible 30-year long trends supporting for the production of large model ensembles.
“One relates to how heat moves from the tropics to the poles and the other is associated with the seasonal cycle.