AMOC/Atlantic Ocean circulation is nearing devastating tipping point - New Study

Billcarson

https://www.boards.ie/discussion/comment/121758374#Comment_121758374

So human activity can have an effect on the atmosphere!!!!!

Billcarson

https://www.boards.ie/discussion/comment/121758313#Comment_121758313

In the 00s the planet wasn't cooling was still getting warmer. From 98 - 2012 the RATE of warming decreased but has since sped up again.

cnocbui

https://www.boards.ie/discussion/comment/121758413#Comment_121758413

The ozone hole has near nothing to do with climate and was all about letting through increased amounts of UV radiation in one small area of the world, which in whities, leads to increased incidence of melanoma. NZ still has the highest levels of UV in it's sunlight due to being under the hole a lot. 2023 apparently had one of the largest holes on record, so perhaps I misspoke in believing that things were getting better.

Billcarson

https://www.boards.ie/discussion/comment/121758458#Comment_121758458

I corrected that to atmosphere which I should have said rather then climate.

Billcarson

https://www.boards.ie/discussion/comment/121758458#Comment_121758458

https://atmosphere.copernicus.eu/twists-and-turns-2023-southern-hemisphere-ozone-hole

Yes the hole was big last year again. This article suggests perhaps the Hunga Tonga eruption may have been a cause disrupting what has been a slow recovery. I'm not saying that is the reason. May or May not be.

littlema

Screenshot_20240212_161235_com.android.chrome.jpg

Slightly worrying that the discussion on 1m floods generated this ad on my Boards page! 🤣 🤣 🤣

aidanodr

https://www.boards.ie/discussion/comment/121757017#Comment_121757017

Clarification and updated thoughts from Prof Stefan Rahmstorf on this new study

"I gather some misunderstand this paper as an unrealistic model scenario for the future. That’s wrong. This type of experiment is not a future projection at all, but rather done to trace the equilibrium stability curve, from which an early warning indicator was then developed. The conclusion that the AMOC is "on course to tipping“ is based on applying that indicator to *reanalysis data* (observations-based products), as shown in Fig. 6 of the paper.

In other words it’s observational data from the South Atlantic which suggest the AMOC is on tipping course."

https://twitter.com/rahmstorf/status/1756404199464505540

Link to paper mentioned is in the OP of this forum thread on page 1, first post

Billcarson

https://www.irishtimes.com/environment/climate-crisis/2024/02/16/ireland-must-prepare-for-atlantic-meridional-overturning-circulation-collapse-ff-senator-warns/

Dial Hard

https://www.boards.ie/discussion/comment/121758313#Comment_121758313

We've reached peak Boards, folks.

Even when it was the bears, I knew it was the immigants!

cnocbui

https://www.boards.ie/discussion/comment/121775587#Comment_121775587

Containing the usual political bollox:

"He said he was encouraged by the Government’s ongoing work on climate adaptation, preparing for inevitable impacts from climate disruption."

Yeah, like the grand plan to get everyone off kerosene fuelled CH and force them onto heat pumps, which don't work terribly well at sub zero temperatures.

Houses built to passive standards is an all-round good idea.

But the usual climate change BS of attributing a change in the AMOC to anthropogenic global warming, when that graph I posted a few posts back clearly shows this has all happened before, time after time, when humans were dressed in furs and the height of their CO2 output was the open fires they cooked on.

https://www.boards.ie/discussion/comment/121749183#Comment_121749183

I could be completely wrong on this, but I vaguely remember a tv programme a good while back about the Royal Irish Academy's survey of Clare Island off the coast of Mayo. It mentioned a period of only 20 years of a change from a glacial to an interglacial period. In a geological time scale this would be considered virtually instantaneous.

cnocbui

https://www.boards.ie/discussion/comment/121776119#Comment_121776119

This one seems a bit tricky. I have seen claims of evidence that glaciation onset only takes a few years, as in less than a decade, and others that it takes 400-450 years. The latter does seem more believable in that a given cubic metre of sea water supposedly takes about 400 years to circulate the Atlantic back to it's point of origin, and since that current is what transports the heat to Europe, and is an immense moving mass that simply could not just stop dead suddenly.

Completely irrelevant to the truth of the matter, but I like the near instantaneous onset theory more. Though one shouldn't like the prospect of an end to the interglacial period we are in because what comes next is many billions of humans dying.

Isn't it amusing how we've gone from 'if we don't stop generating CO2 and limit global temperature rise to 1.5°C, we are all doomed' to if the AMOC shuts down, we are all going to freeze and are doomed, in less time than it takes a climate scientist to change a light bulb.

.Donegal.

While this pertains to Britain we can get a good idea of the effects for us in Ireland based off Rene prediction.

If AMOC collapsed Rene van Westen, a climate scientist and oceanographer at Utrecht University, predicts that temperatures in Britain will be around 3 to 5 °C lower in summer than they are now.

Winters would be 10 to 15c lower.

Annually the difference would be around 7c lower in London up to 12c lower in N Scotland.

mikeecho

I'm still waiting for:

The new ice age

Nuclear Armageddon

Peak oil

Acid rain

Nuclear Armageddon

The hole in the ozone

Nuclear Armageddon

Melting of the poles

I'm not denying that humans are altering the planet, but there just seems to be some global catastrophe, that will happen, but never does.

And Y2K is in there somewhere as well

InAtFullBack

https://www.boards.ie/discussion/comment/121758413#Comment_121758413

Of course! Cut down 50 acres of woodland and tarmacadam over the whole lot. Come back to me and let me know how the thermometers react to that.

M.T. Cranium

There are a lot of people working on this field of research and they all seem to disagree by orders of magnitude on what is going to happen, so I can't really draw any conclusion, this thread happens to quote one of many studies, others say changes will be less dramatic or in some cases more dramatic. Nobody today really knows what is going to happen, if indeed anything significant actually does happen. I am not trying to dismiss concern about it, just a reality check that the scientists involved in the research have many different perspectives and there is no "settled science" in this area yet.

Akrasia

Of course, by the time we're certain of the outcomes, it will be too late to stop it (may already be too late) but given the risk of this occuring being much higher than most scientists are comfortable with, and the high impact of this kind of event, it would be prudent to try to take measures to avoid it

Luckily, most of the things we need to do to avoid the worst impacts of climate change are the same to avoid the AMOC shutting down, and we already know that the impacts of climate change are very likely to be severe if we don't succeed and stablise the atmospheric concentrations of GHGs

cnocbui

https://www.science.org/doi/10.1126/science.aaf5529

We have been in an ice-age for about 3 million years. This has been characterised by long glacial periods, interspersed by short, warm, interglacial periods, such as the one we have been experiencing these last 12,000 years or so.

No one knows what modulates these interglacial switching events, and it's not Milankovich cycles (look up the 100,000 year problem). What ice core data and sediment proxies do show is that there appear to be 4 notable events that occur right at the end of interglacial periods, just before their end and the transition to the next glacial period:

1) There is a rapid rise in average global temperature

2) There is a rapid rise in global atmospheric CO2 levels

3) The AMOC shuts down

4) Large icebergs break off Antarctica and travel much further north than normal, as in New Zealand kinds of latitude.

The thing is, there is no understanding of what caused these temperature and CO2 rises at the end of previous interglacials.

But climate scientists are absolutely certain that this time it's different, this time it's solely due to Anthropogenic CO2, despite not knowing what caused CO2 levels to rise so much, at fairly regular intervals, over the past 400,000+ years. One thing seems certain, it wasn't due to anything the Neanderthals were doing.

5,000 years ago a large flotilla of icebergs reached NZ, but as we all know that is quite impossible because it would suggest Antarctica warmed up a bit, and as we all know, that couldn't possibly have happened because it's never been as warm as it is now.

M.T. Cranium

Wouldn't an increase in icebergs in temperate latitudes be associated with a colder polar or subpolar climate pushing the sea ice margins towards the north in this case (towards NZ)?

cnocbui

https://www.boards.ie/discussion/comment/121801081#Comment_121801081

I don't think so, but I could be wrong. An iceberg did reach NZ in 2006. My thinking is that icebergs melt as they drift, so to reach higher latitudes they might have to be bigger than normal in their initial form and so sourced from larger than normal breakups of ice shelves or increased calving from glaciers, which likely are triggered by higher temps. Perhpas being bigger they tend to hook up with the circumpolar current more readily and that gives them a northerly impetus due to the centripetal force, which is large enough that the Earth isn't sperical but bulges at the equator slightly.

https://www.nzherald.co.nz/nz/giant-icebergs-likely-for-nz-in-global-warming/TTYIFJVEVNLYIU2FU6T3G3REWI/

Looks like I was mistaken in thinking that the icebergs were wholly an effect of warming, one paper at least suggests they could also be a major trigger. Still, sometheng else needs to happen to get them further north so I'd say they are more likely to be a coup de grâce than a trigger.

https://news.climate.columbia.edu/2021/01/13/far-drifting-antarctic-icebergs-trigger-ice-ages/

seansouth35

https://www.boards.ie/discussion/comment/121758313#Comment_121758313

Sums up the idiocy of the climate deniers! The Montreal Protocol was a multilateral agreement to ban CFCs which is why the hole in the ozone layer began to repair. The rest of your arguments are straw man nonsense used to justify your baseless beliefs.

aidanodr

relevant to this topic?

From Brian McNoldy - Senior Research Associate at the Univ. of Miami Rosenstiel School. Hurricanes, climatology, & sea level rise

https://twitter.com/BMcNoldy/status/1760690880867185017

Also he added - "And just for the sake of perspective on this type of anomaly, if I apply the same outlier status (4.5 standard deviations from the 1991-2020 mean) to an Atlantic hurricane season, there would be 38 named storms, 21 hurricanes, 11 major hurricanes, and 410 ACE."

Billcarson

https://www.boards.ie/discussion/comment/121802746#Comment_121802746

The disturbing thing is that comment got 6 likes. This being a weather forum makes that fact even worse.

Longing

https://www.boards.ie/discussion/comment/121804351#Comment_121804351

I give it a like to make it 7 likes. So what will we call it now truly disturbing.

Billcarson

https://www.boards.ie/discussion/comment/121805077#Comment_121805077

You may find it all funny etc but time will tell regarding climate change. Its already telling but clearly not enough for those that deny it or at least those that deny that humans are the cause. Time always tells in the end. I doubt those that come after us will find it all that funny. Not saying they are all doomed but challenging times will be coming for humanity.

Longing

https://www.boards.ie/discussion/comment/121805585#Comment_121805585

No don't find it funny at all I am open to science but its definitely not settled. Just when you posted that 6 people like a post it was disturbing. Well you see people will always have different views in every part of life are these people disturbed (Need mental valuation) no they do not. It didn't fit your view on it. Your view could be correct I don't know. AMOC/Atlantic Ocean circulation study I know nothing on it. Its the first I heard of such a report.

Almost 40 years ago I heard of another report by United States Environmental Protection Agency on Acid rain. Still no warnings on Met Eireann to stay in doors. What I'm trying to say here is not every report is gospel. Not for one min downplaying this AMOC report but no matter how hard we try time is the real truth. That's were the conflict of issues arise.

BlueSkyDreams

https://www.boards.ie/discussion/comment/121805585#Comment_121805585

There is still a lot of scepticism.

Too many boy cried wolf stories about the climate disasters to bring the masses onboard.

The scaremongering stoies about Dublin beimg underwater and London the same, just appear as agenda driven nonsense by invested parties.

The general population just doesnt believe it.

cnocbui

https://www.boards.ie/discussion/comment/121804351#Comment_121804351

Don't worry, there is a legislator in Canada who just tabled a bill to make it illegal to commercially promote or say anything in favour of fossil fuels. I'm sure ER or some other Irish nut-job would be happy to try something similar here for people who post AGW sceptical posts, or upvote them.

A curious clause bans the suggestion that the burning of some hydrocarbons and the emissions caused are “less harmful” than other fossil fuels. This provision would make it illegal to state the scientific fact that burning natural gas produces less than half the carbon dioxide than the burning of coal. It would also be an offence to suggest that the use of hydrocarbons would lead to positive benefits for the environment, the health of Canadians and the global economy. Whatever the facts based in science or economic observation, all these ‘wrong’ thoughts can be punished with a C$500,000 fine and two years in prison.

And this isn't the first time people have suggested sceptics and 'climate deniers' be imprissoned for their views. There is not a little of that on boards already, with adherents to the religion of AGW suggesting sceptics and non believers have less intelligence than they do and should be derided for their mental incompetence. Got a mirrror handy?

Billcarson

https://www.boards.ie/discussion/comment/121807241#Comment_121807241

Well imprisonment of people for their views would be going way too far. People can believe whatever they want. I'm not going to change you and others minds anymore then you are going to change mine. I believe in the science of the current situation. If you believe and rightly so that the climate has always changed and we know this from science and what scientists have told us. So why believe they (or many of them) have got it so wrong now? Regarding the current situation. Sounds like a contradiction to me.

We have been lucky the last 10,000 yrs or so. The climate has been relatively stable in that time which has allowed humans to flourish and create civilisations. Whatever humans do or don't do the climate will change at some point of course anyway. With nature it's all a game of chance and luck. We've been on a roll. I believe we are playing with that luck now. I'd rather not take the chance that maybe the science could be wrong. We have to clean up our act anyway.