Ocean circulation in North Atlantic is at its weakest for 1,500 years ... Mini Ice Age?

The mental gymnastics from the left is a thing of beauty.


Global warming is causing a fricking ice age. This is just great.

Yeah, yeah, "Day After Tomorrow"

Everyone above Tennessee is dead and the rest of us had to move to Mexico but only after POTUS forgives all latin American debt...

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Global warming is causing a fricking ice age. This is just great.

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Ice Ages are caused by a lack of heat and energy transfer from the tropics to the polar regions. That disruption was first made possible by the closing of the isthmus of Panama, which disrupted ocean currents flowing between the Atlantic and the Pacific, regulating the world temperatures.

What would cause a "mini ice age" (i.e., one confined to the north Atlantic region) is a shutdown of the ocean current known as the Mid-Atlantic Conveyor, of which the Gulf Stream is a part. The Mid-Atlantic conveyor takes warm water water from the tropics and brings it up the east coast of the U.S. to Canadian waters. Because cold water is denser than warm water, as it cools, the water sinks and is then pulled south, back to the tropics along the Western coast of Europe and Africa, where once it heats, it then rises back through the water column and recycles.

In the recent geologic past (i.e. last few million years), the conveyor operates this way during interglacial periods (which often last thousands of years) only to shutdown during glacial periods. What causes the shutdown is a change in salinity. Salt water is more dense than freshwater. When the salinity drops too low due to melting glaciers, the conveyor shuts down, cutting off the polar regions from energy from the tropics. The polar regions get significantly colder and glaciers begin to grow again. Despite the fact that all of this additional glaciation should cause the salinity to drop enough to restart the conveyor, once the new ocean currents establish themselves, it takes a very long time (hundreds if not thousands of years) before the temperature difference gets great enough to start sucking warm water north strongly enough to re-start the conveyor.

Basically, if we assume global warming is happening (I know this is a big if, but just stay with me here to complete the hypothetical), and that warming is responsible for increased melting at the poles, then it could be adding enough freshwater to the northern Atlantic to upset the delicate water-density balance that keeps the conveyor flowing. Then, if ocean circulation is getting weaker as reported, that could indicate that the process of the conveyor shutting down is already underway, and a "mini ice age" could be coming soon as a consequence of global warming heating the ice caps.

On the flip side, this is hardly unprecedented in human history. The last "little ice age" (which resulted in part due to a weakening, but not a total shutdown, of the conveyor) occurred between the early 14th century and mid-19th century. It's peak, the Maunder Minimum from 1645-1715, was thought to be caused by a major low in observed sunspots. The 1815 eruption of Mount Tambora was thought to have combined with the Little Ice Age to create 1816's infamous "Year Without a Summer" which spurred massive crop failures all over Europe.

So, while a return to a "Little Ice Age" could be bad for a lot of people, it's not like mankind hasn't thrived through one before.

ETA: I had accidentally said freshwater is denser than salt water. The inverse is true. It has been edited and should be correct now. Mea culpa

Now, if the conveyor shuts down completely, then we will be plunged into a real ice age. Granted, many geologists believe that we never truly left The Ice Age. Warmer interglacial periods are common in the geologic record, some last thousands of years. It is entirely possible that we are simply near the tail end of a particularly long interglacial period and could be seeing the tell-tale signs that said interglacial period is about to end, and when they end, they do so suddenly, violently, and dangerously. A return to a full-scale ice age could threaten mankind with extinction, or at minimum, civilization-scale collapse, not just be a minor inconvenience or cause a few crop failures here and there. Rivers would change course, oceans would recede, coastlines would be altered permanently, massive glaciers would advance and swallow cities under mile-thick sheets of ice. I'm talking fertile plains turned to Tundra, forests into deserts, deserts into grasslands, inland seas turning into river valleys, coastal ports into mudflats, a complete sea-level change and massive, irreversable geologic and geographic change. If this is the prelude to a return to the REAL Ice Age, we're all f&%ked. If this is another mini-Ice Age, it's not great, but we'll live. If it's nothing, then it's just a whole bunch of hoopla over nothing.

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If this is the prelude to a return to the REAL Ice Age, we're all f&%ked.

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True, but it wouldn't happen in our lifetimes or our children's lifetimes. It'd take a while for these changes to become absolute.

But yes, fricked.

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Now it’s “climate change”

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We have had climate change on this planet since it was created. Nothing ever stays the same it is always changing.

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So, what can we do about it?

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Well, that is uncertain. Even if we assume that global warming exists, is 100% caused by man, is melting polar ice, and that melting polar ice is contributing enough fresh water to weaken the conveyor, there's no way of knowing whether the conveyor has already been weakened beyond our ability to repair or if the conveyor would repair itself if we stop causing the warming. We have no way of knowing just "how far gone" we are. If we're already past the point of no return, then enough ice has already been melted to flip the salinity switch and turn down the conveyor.

On the other hand, if it's not broken, this may be a fluctuation that, while an outlier, is still within the normal operational range for the conveyor to keep working, but if this weakness persists, then it would break down. The conveyor's circulation fluctuates annually and seasonally. In that case, we may still have time to stop what we are doing that is causing the warming, which will slow down the melting of the ice caps, and will keep the conveyor from shutting down.

So, we may all be completely f&%ked or just a little f&%ked. We may have f&%ked ourselves beyond repair; be in the process of f&%king ourselves, but still have the opportunity to stop; we're not f&%ked at all because this is fluctuation (while concerning) is still normal; or we're completely f&%ked, a little f&%ked, or not f&%ked at all and have absolutely nothing to do with it and nothing we can do about it.

WINTER IS COMING....

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Now, if the conveyor shuts down completely, then we will be plunged into a real ice age. Granted, many geologists believe that we never truly left The Ice Age. Warmer interglacial periods are common in the geologic record, some last thousands of years. It is entirely possible that we are simply near the tail end of a particularly long interglacial period and could be seeing the tell-tale signs that said interglacial period is about to end, and when they end, they do so suddenly, violently, and dangerously. A return to a full-scale ice age could threaten mankind with extinction, or at minimum, civilization-scale collapse, not just be a minor inconvenience or cause a few crop failures here and there. Rivers would change course, oceans would recede, coastlines would be altered permanently, massive glaciers would advance and swallow cities under mile-thick sheets of ice. I'm talking fertile plains turned to Tundra, forests into deserts, deserts into grasslands, inland seas turning into river valleys, coastal ports into mudflats, a complete sea-level change and massive, irreversable geologic and geographic change. If this is the prelude to a return to the REAL Ice Age, we're all f&%ked. If this is another mini-Ice Age, it's not great, but we'll live. If it's nothing, then it's just a whole bunch of hoopla over nothing.

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Goddamn...that's beautiful.

What's even better is that it is 100% accurate and backed up with reams of real science.

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It sounds like something that we just have to adjust for if/when it comes.

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Don't tell the sky screamers this, they aint real good about "adjusting" or preparing to take care of a problem...