Guest “why even bother”? by David Middleton

From the American Association for the Advancement of Science of America and YouReek Alert…

From the totally fracking useless files…

Simulations by scientists from the University of Groningen and Utrecht University showed that it is unlikely that the current will come to a complete stop, due to small and rapid changes in precipitation over the North Atlantic. However, there is a 15 percent likelihood that there will be a temporary change in the current in the next 100 years. 

Eureka Alert

So… There’s an 85% probability that nothing happens and a 15% chance that something might briefly change a little bit for a brief period of time at some point in the next 100 years. How is this useful at all?

It gets more useless…

The idea was to use this box model to estimate the likelihood of small fluctuations in freshwater input causing a temporary slowing down or a total collapse of the North Atlantic Current. The current shows non-linear behaviour, which means that small changes can have large effects. The evolution of the physics described by the box model can only be obtained using simulations. ‘As the transitions we were looking for are expected to be rare events, you need a huge number of simulations to estimate the chance of them happening,’ says Wubs. However, the Dutch scientists found that a French scientist had devised a method to select the most promising simulations, reducing the number of full simulations required.

Sven Baars, a PhD student of Wubs, implemented this method efficiently and linked it to the Utrecht box model. Daniele Castellana, a PhD student of Dijkstra, performed the simulations. ‘These simulations showed that the chances of a total collapse of the North Atlantic Current within the next thousand years are negligible,’ says Wubs.

Eureka Alert

“However, the Dutch scientists found that a French scientist had devised a method to select the most promising simulations, reducing the number of full simulations required.”

This reads like the Weekly World News article about the World War II B-17 Flying Fortress bomber being spotted in a crater on the Moon, according to Russian scientists, as reported by Swedish scientists. Almost all Weekly World News “science” articles took the form of, “according to Russian scientists, as reported by Swedish scientists.” In this case the Dutch scientists found that a French scientist had discovered cherry-picking.

The really fracking hilarious thing is that even with the newly discovered Franco-Dutch cherry-picking method, they still couldn’t simulate The Day After Tomorrow…

“‘These simulations showed that the chances of a total collapse of the North Atlantic Current within the next thousand years are negligible,’ says Wubs.”

Not so fast! The cancellation of the apocalypse requires confirmation…

A temporary interruption in the delivery of relatively warm water to north-western Europe is more likely: ‘In our simulations, the chances of this happening in the next 100 years are 15 percent.’ Such temporary transitions may cause cold spells in the North Atlantic, although this needs to be verified in further studies. Therefore, the current study is just a first step in determining the risk. The model does not take into account considerable changes in freshwater in the North Atlantic, which can be caused by the melting of the ice sheets. Wubs: ‘Confirming our results through simulation with a high-resolution climate model will be the next challenge.’

Eureka Alert

Confirming model results with another model always seems to be the next step in modern climate “science.”

Had I just read the paper before reading the press release…

As is usually the case, the paper is not nearly so bad as the YouReek Alert press release. The paper is actually quite good, as far as models go.

Transition Probabilities of Noise-induced Transitions of the Atlantic Ocean Circulation
Daniele Castellana, Sven Baars, Fred W. Wubs & Henk A. Dijkstra
Scientific Reports volume 9, Article number: 20284 (2019)

Abstract
The Atlantic Meridional Overturning Circulation (AMOC) is considered to be a tipping element of the climate system. As it cannot be excluded that the AMOC is in a multiple regime, transitions can occur due to atmospheric noise between the present-day state and a weaker AMOC state. For the first time, we here determine estimates of the transition probability of noise-induced transitions of the AMOC, within a certain time period, using a methodology from large deviation theory. We find that there are two types of transitions, with a partial or full collapse of the AMOC, having different transition probabilities. For the present-day state, we estimate the transition probability of the partial collapse over the next 100 years to be about 15%, with a high sensitivity of this probability to the surface freshwater noise amplitude.

Scientific Reports

The full text is available. They basically determined that random climate “noise” could possibly briefly disrupt the AMOC.