From NOT A LOT OF PEOPLE KNOW THAT
By Paul Homewood
h/t Patsy Lacey
It’s the usual scam:
The circulation of the Atlantic Ocean is heading towards a tipping point that is “bad news for the climate system and humanity”, a study has found.
The scientists behind the research said they were shocked at the forecast speed of collapse once the point is reached, although they said it was not yet possible to predict how soon that would happen.
Using computer models and past data, the researchers developed an early warning indicator for the breakdown of the Atlantic meridional overturning circulation (Amoc), a vast system of ocean currents that is a key component in global climate regulation.
They found Amoc is already on track towards an abrupt shift, which has not happened for more than 10,000 years and would have dire implications for large parts of the world.
Amoc, which encompasses part of the Gulf Stream and other powerful currents, is a marine conveyer belt that carries heat, carbon and nutrients from the tropics towards the Arctic Circle, where it cools and sinks into the deep ocean. This churning helps to distribute energy around the Earth and modulates the impact of human-caused global heating.
But the system is being eroded by the faster-than-expected melt-off of Greenland’s glaciers and Arctic ice sheets, which pours freshwater into the sea and obstructs the sinking of saltier, warmer water from the south.
Amoc has declined 15% since 1950 and is in its weakest state in more than a millennium, according to previous research that prompted speculation about an approaching collapse.
Until now there has been no consensus about how severe this will be. One study last year, based on changes in sea surface temperatures, suggested the tipping point could happen between 2025 and 2095. However, the UK Met Office said large, rapid changes in Amoc were “very unlikely” in the 21st century.
The new paper, published in Science Advances, has broken new ground by looking for warning signs in the salinity levels at the southern extent of the Atlantic Ocean between Cape Town and Buenos Aires. Simulating changes over a period of 2,000 years on computer models of the global climate, it found a slow decline can lead to a sudden collapse over less than 100 years, with calamitous consequences.
The paper said the results provided a “clear answer” about whether such an abrupt shift was possible: “This is bad news for the climate system and humanity as up till now one could think that Amoc tipping was only a theoretical concept and tipping would disappear as soon as the full climate system, with all its additional feedbacks, was considered.”
As with a lot of climate scams, this one is based on just a few years data, from which the “scientists” conclude that they have identified cataclysmic changes that have not happened for millennia.
The Met Office give a more balanced summary:
Not this particular sentence:
Oceanographers have been measuring the AMOC continuously since 2004. The measurements have shown that the AMOC varies from year to year, and it is likely that these variations have an impact on the weather in the UK. However it is too early to say for sure whether there are any long term trends. Before 2004 the AMOC was only measured a few times,
So we only have data since 2004, and the year to year variations are large. To pretend that such a short series is in any way significant is not only unscientific but fraudulent.
This is what the series shows:
It would appear that there is little trend since around 2008.
The idea that the AMOC never changed before 2004 is absurd anyway.
Bob Dickson & Svein Østerhus laid out in their study, “One hundred years in the Norwegian Sea”, the major climatic changes in the Norwegian Sea and the rest of the Arctic:
All were associated with changes in Atlantic currents and the AMOC. The Warming in the North, for instance, occurred because of the influx of warm Atlantic seawater, in exactly the same way as with recent Arctic warming. As the Met Office explain, warm water evaporates leaving saltier water, which sinks because it is more dense. Saltier water of course freezes at lower temperatures, so Arctic sea ice tends to contract. (Note when it freezes, the salt tends to leech out, so either way the sea becomes saltier).
The Great Salinity Anomaly which followed the Warming was the result of that influx of warmer water retreating, in part because of northerly airflow :
http://www.tandfonline.com/doi/pdf/10.1080/00291950701409256
These weather patterns are part and parcel of the Arctic Oscillation, another perfectly natural cycle. The anomalously higher pressure over Greenland marks the time of the negative AO:
From NSIDC:
As fresh, polar water replaced warmer Atlantic water, salinity levels fell – hence the name given to the event. Just as Arctic sea ice had retreated during the Warming, it expanded rapidly during this period. The GSA was not just a phenomenon in the Norwegian Sea, because the polar gyre carried this fresh water around the whole of the Arctic Ocean.
Another factor identified by Dickson and Osterhus in the freshening of the Arctic Ocean is increasing discharge from Eurasian rivers into the basin. A warming climate means a wetter climate in those regions. And more river discharge leads to more sea ice and a colder Arctic.
In other words, these processes tend to be self correcting. Milder weather leads eventually to more sea ice and a colder climate, until eventually the AO flips back to positive again.
I’ll leave the final comment to Dickson & Osterhus:
All these changes were the result of natural processes. There is no evidence that these will change in future.
just let the Chinese company build the sea level canal in Nicaragua. the warm equatorial current will flow into the pacific, instead of back out the straits of Florida and into the north Atlantic. it will be like before the Isthmus Panama closed off, no more ice ages