Stronger evidence for a weaker Atlantic overturning circulation Gulf Stream current at its weakest in 1600 years, studies show The Atlantic Ocean Overturning is the slowest in the last 1600 years, reveals new study

Stronger evidence for a weaker Atlantic overturning circulation

Through two new studies in Nature , the weakening of the Gulf Stream System is back in the scientific headlines. Both can be attributed to a weakening of the AMOC in the model simulation. The green curve shows changes in water mass based on deep sea coral data, the blue curve shows the grain sizes mentioned and the yellow curve shows the RAPID measurements discussed above. And finally, Smeed et al.

It is not a question of will the slowing occur but what is the rate of the occurrence. But climate models can not even predict “past weather”. (The use of the phrase predicting the past is strange). Truth is you can’t convince anyone to go look up the truth of a matter when their personal identity/ego depends on not going and looking it up only to discover they’re wrong. You see attacks on Darwin by people who think his occasional errors somehow undermine evolution.

I AGREE with you! Got that? Now we’re starting to see inter-corporate struggles between RE companies and the fossils. The study by Thornalley and colleagues, published in Nature , used cores of sediments from a key site off Cape Hatteras in North Carolina to examine Amoc over the last 1600 years. So, if the AMOC weakens, the strength of the current of the Gulf Stream weakens. Let’s start with tomorrow’s issue of Nature , which besides the two new studies ( one of which I was involved in) also includes a News&Views commentary.

The three remaining curves are based on temperature changes – but also on three different methods. Geophysical Research Letters on the latest measurements in the RAPID project, which are also included as a linear trend in Fig. Before you criticise climate models don’t you think you first ought to learn what they actually are? If it is decades then we are all finished but if it is centuries then we have time to pull up our socks and work on it.

Remaining ego friendly means not being motivated to go look something up in a scientific field where the ego is not the expert. I keep running into recurring commentary on the snarkiness of the scientists behind these e-mails. Science is alchemy: it turns shit into gold. When you learn that models do not know how to treat areosols and clouds, but those models are used to support the statement that 100 percent of the warming is caused by man, take notice.

An example I witnessed personally (in part) was the recent skirmish over the 2% cap on rooftop solar here in South Carolina. They also used the shells of tiny marine creatures from sites across the Atlantic to measure a characteristic pattern of temperatures that indicate the strength of Amoc. Shivangi Sharma is a budding journalist who intends to build a bright career in the media industry. Everything revolves around the question of whether the Gulf Stream System has already weakened.

The curve from Rahmstorf et al. It does that in such a way that an influx of warm air from the south into Europe is encouraged. He would be doing so retrospectively, fitting a curve by scaling without any strictures on the amplitudes of the scaling, and probably varying the weighting along the way. I realize that this is off topic, but DDS’s ignorant comments seem to stem at least in part from a failure to understand scientific modeling.

Tell them a truth a thousand times even and it will make no difference. They’re really entrenched, people seem surprised to note. As for me, I’ll follow the blogs with interest and see how this all shakes out. So my solution is voice your opinion and let others do the same even if you do not like their opinion. Thus, shifting to RE is not only a no-regrets climate mitigation strategy, it’s likely a net win in terms of energy access, economics, and public health.

Both studies found that Amoc today is about 15 percent weaker than 1,600 years ago, but there were also differences in their conclusions. Notify me of follow-up comments by email. Climate models predict this will be one consequence of global warming – alongside other problems such as rising sea levels and increasing heat waves, droughts and extreme precipitation. We now wanted to know what temperature changes the observational data show since the late 19th century.

In summer 2015, the subpolar Atlantic was colder than ever since records began in the 19th century – associated with a heat wave in Europe. This would be a bit like making a fourier description of a time series using a set of sinusoids, but using the “random” numbers as the sinusoids. It makes me wonder whether some of the other lay readers might benefit from a general discussion of scientific modeling.

Proof is all around. Got a real siege mentality going on, speak unkindly of the skeptics, take all kinds of cheap shots unbecoming of the lab coat. On longer time frame, I would agree. You haven’t answered my question and suggested any better way to do science, and have just posted fallacies about the science and propoganda. Still, it’s a far more favorable picture in that regard than anyone dared to dream a decade ago.

The second study suggests most of the weakening came later, and can be squarely blamed on the burning of fossil fuels. This Gulf Stream meme has been around for many years and every so often is resurrected. But is such a slowdown already underway today? My doctoral student Levke Caesar evaluated the various data sets. And the new curve from our study (dark blue) uses measured sea surface temperatures, as shown in Fig.

But really very, very unlike the much more constrained operation of a climate model, which has to relate to the scalings of real physical processes. It’s perhaps not one of our more admirable human abilities, but there it is. Illustratively, there can be–are, mathematically speaking–infinitely numerous data sets for any given mean. Some people even believe that climate science and climate scientists will save the world from the looming disasters of climate change.

Gulf Stream current at its weakest in 1600 years, studies show

The findings, based on multiple lines of scientific evidence, throw into question previous predictions that a catastrophic collapse of the Gulf Stream would take centuries to occur.

El Nino, Global Warming, and Anomalous U.S. A 2004 disaster movie, The Day After Tomorrow , envisaged a rapid shutdown of Amoc and a devastating freeze. There is no evidence that the Gulf Stream is about to stop. This question is easier asked than answered. I know of no other mechanism that could explain this spatial and temporal pattern than a weakening of the AMOC. Time evolution of the Atlantic overturning circulation reconstructed from different data types since 1700.

DDS wants to believe that climate models fit the climate record that way, so he believes it. In reality, of course, anthropogenic global warming was predicted (in 1896) on the basis of radiation physics. However, it may well be that what we need to know is that value of the mean. Nor would they admit they were deliberately spreading lies about the solutions to it. The “debate”, such as it is, is political and entirely dishonest at its heart.

A question related to the suggested (by one) analogy of climate models and curve fitting. So, Dan, I am curious. Myth vs. The basics of the science were portrayed correctly, said Thornalley: “Obviously it was exaggerated—the changes happened in a few days or weeks and were much more extreme. Other scientists totally disagree. The Atlantic Meridional Overturning Circulation (AMOC, also known as Gulf Stream System ) is a huge, three-dimensional flow system throughout the Atlantic, which fluctuates on different time scales.

The scales on the left and right indicate the units of the different data types. And a number of studies suggest that if the AMOC weakens, sea levels on the US coast will rise more sharply (e.g. Dan De Silva @40, thanks for the video link, and you summarised M Manns comments on models ok, however the consensus that agw is 100% human caused doesn’t come from climate modelling alone. Given that CO2 is a greenhouse gas (Tyndall 1858), and given that burning coal produces more of it, the Earth should warm up.

Deniers are everywhere denying the overwhelming evidence of all kinds of things. It’s not a hippie love-in; it’s rugby. Why does it take so long in this case? I can appreciate that curve fitting doesn’t really make sense when talking about running climate models initialised on historical data and comparing the output to observations. What precisely do you think “scientific consensus” is?

Investigative journalism has never been more important. Copyright © 2013-2018. If you want to look further back in time, you have to look for other sources of evidence. These deposits gradually accumulate over thousands of years and tell us what happened in the ocean in the past. The blue curve was shifted to the right by 12 years since Thornalley found the best correlation with temperature with this lag.

The agw consensus is based largely on numerous studies of natural casues, solar irradiance patterns, volcanic activity, the nature of the greenhouse effect etc. As I recall realclimate did do a simple climate model at one point. The models are quantized much more coarsely than reality is. Carrie greatly misunderstands how the scientific method works. Every time you put out a paper, the guy you pissed off at last year’s Houston conference is gonna be laying in wait.

My question is, are there paramaterizations in the climate models which can be tweaked so that model hindcasts can replicate historical climate change? It does not about an “agreed upon” opinion of scientists, but rather an overwhelming preponderance of evidence in support of a theory, fact, technique or approach. AIP:Discovery of Glob. Share this article. The TeCake. This model simulation took six months on 11,000 processors (9,000 of them for the ocean alone) of the high-performance computer at NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton.

Makes sense: it takes a while until a change in currents alters the temperatures. The impacts are currently being further researched, but a further AMOC slowdown cannot be considered good news. Like Killian says climate models aren’t broken. However I think with most denialists something slightly different is going on, a bit more subtle but still inexcusable. I don’t know what you mean by this.

Every time you think you’ve made a breakthrough, that asshole supervisor who told you you needed more data will be standing ready to shoot it down. As far as models I was pointing out why they should be treated with skepticism, not that the climate scientists are abusing them as badly as my example. Climate models cannot resolve all scales and so must use parameterizations to take into account sub grid scale processes which are non-negligable.

AMS Env. California Gov. The central result is shown in Fig. From these, the strength of the heat transport and thus the flow can be deduced, similar as in our study. The curves all show a long-term slowdown that is accelerating. Yet, although the oscillations seen in Fig. And don’t get obsessed with the way models are used to hindcast past climate trends. I hope I’m not conflating it.

The Atlantic Ocean Overturning is the slowest in the last 1600 years, reveals new study

A new study has revealed that the Atlantic Ocean circulation or the Atlantic overturning has become the weakest in the last 1600 years. The study says the

I’m thinking something analogous to numerically solving the Reynolds averaged Navier Stokes equations for turbulent flow. The other thing is that it is not a democratic process. Penn State Inst. Where Icebergs go to die... Trends in sea surface temperatures. The neat thing is that the current sorts the sediment. The red curve is so smooth because these particular sediment data have too low a time resolution to show shorter fluctuations.

Only if you manipulate the data. It would be easy to assume the paid denialists are smart enough to know perfectly well weather is not climate, but I have a hunch its a 50 / 50 split. And the modeling process seems to me to be one that leads to understanding, in that to build an accurate model you have to cross-compare time and again between model and observation(s). Unless, of course there is a conspiracy going on such that scientists of all stripes in every country in the world must toe some specific line.

You appear to be really suggesting scientists tamper with data or come up with fake equations for political reasons, so because its a serious accusation, you have a duty to show explicit proof. Some of these closure schemes have constants which can be specified according to the type of turbulence simulation being modelled. The scientists who know the field the best (e.g. those who have published the most and most influential papers) have the largest voice.

A new study has revealed that the Atlantic Ocean circulation or the Atlantic overturning has become the weakest in the last 1600 years. Left: in the climate model CM2.6 in a scenario with a doubling of the amount of CO2 in the air. The authors conclude from their data that the AMOC has never been as weak in all those previous centuries as in the last hundred years. In our study we conclude that the AMOC has weakened by about 15% since the middle of the 20th century.

What a strange assumption that his statements are innocently made and questions innocently asked. However its equally indefensible either way, whatever the truth is. You’re constantly asking, “OK, is this bit right? Deniers lack such a feedback mechanism. This is how it works: you put your model out there in the coliseum, and a bunch of guys in white coats kick the shit out of it. You give no specific evidence, and not even a plausible detailed mechanism.

You don’t get a vote. Such a collapse would see western Europe suffer far more extreme winters, sea levels rise fast on the eastern seaboard of the US and would disrupt vital tropical rains. The study says the climate change is the main reason behind the slowing down of Atlantic overturning. Right: in the observation data from 1870 to the present day. What changes in the AMOC do the data show?

Also for 1994-2013, Roessler et al. (2015) found an increase of 1.6 Sv in the transport of the North Atlantic Current. Perhaps it was rhetorical. But what interests me is once people embrace a conspiracy theory they have an excuse to stop thinking and tackling evidence, and its easy to rationalise anything. This is science speaking about the known evidence. BPL: No. If it’s still alive when the dust clears, your brainchild receives conditional acceptance.

Moreover, you’d forget that a major part of those aerosols are anthropogenic in nature, too. I don’t get a vote. The current, known as the Atlantic Meridional Overturning Circulation (Amoc), carries warm water northwards towards the north pole. As per the study, the Atlantic Ocean circulation has declined in strength by 15 percent since the mid-20th century to a “new record low and this has happened due to the changing climate.

The time series from the two new and some earlier studies are shown in Fig. Oltmanns et al (2018 , again in Nature Climate Change ) recently found signs of a growing risk that convection in the Irminger Sea could shut down. For 1994-2009, using sea-level data, Willis et al. (2010) reconstructed an increase in the upper AMOC limb at 41°N by 2.8 Sv. Do you think it humanly possible to engage on a climate website for an extended period and still try to imply or claim seasonal weather equals 30-year climate analyses?

Don’t believe me. Fundamental wrong assumption. It does not get rejected. Peer review helps identify bias and errors. With aerosols you also get little out of proposing a less negative climate feedback of aerosols. Denialist opposition to renewable energy is an interesting case. There it cools, becomes denser and sinks, and then flows back southwards. Atlantic overturning involves warmer water flowing from equator towards the high altitude of the Atlantic and the cold water from there flowing down towards the equator through the deep ocean.

Each of the six curves is based on a different data type and methodology, but they show a largely consistent picture. Sgubin et al. (2017 , Nature Communications ) analyse the occurrence of abrupt cooling in the North Atlantic in various climate models. There is thus no contradiction there, and anyone who has looked at the time series in Fig. Or that any data can be fed into a climate model and get back correct past climate simulations?

People and climate scientists included can look it up in a multitude of papers and connect the dots. Climate models are not curve fits. Science is so powerful that it drags us kicking and screaming towards the truth despite our best efforts to avoid it. Competition in science is fierce and exposes bad science. And you’d also be deceiving yourself once again, by ignoring that scientific studies indicate that those most affected by AGW would be those same poor people.