The worst-case and - unfortunately - looking almost certain to happen scenario
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| Aaron Franklin |
I have asked for the world leading climate and arctic scientists I have been working with at AMEG, and Arctic-News to review this, and if they don't agree with any part or the end conclusion to please inform me immediately.
As yet no-one has come forward, with any criticisms whatsoever, only agreement that this is what we are very likely facing.
If we don't act very fast and the Arctic sea ice goes...
Up till now the sea ice, and the pool of low salinity meltwater left on the surface of the arctic ocean from it melting has blocked the warm Gulf stream from getting any further than the strip of coast with a shallow continental shelf seabed, around the north of Europe and western Russia as far as the islands and peninsulars that jut north from the west Siberian coast.
High salinity, warm gulfstream water of tropical origin does not mix freely with cold low density low salinity meltwater. It mixes and sinks in a sheet current at the boundary between these two bodies of water.
This has not caused any big problems so far as it has been happening along a fairly short boundary above shallow continental shelf and the downwards mixed flow is slowed by flowing over the the shelf before it sinks into the deep polar basin.
However... the meltpool on top of the Arctic ocean has been getting smaller every year and if we let the gulf stream get any further than it has to date then it will most likely continue all the way along the east Siberian coast, combine with the warm bering strait inflow, encircle the whole polar basin. Or at least most of it, if there is still enough multi-year sea-ice damming up against the west coast of the north Canadian archipelago to stop it getting to the extreme Canadian side of the arctic ocean.
There probably isn't enough multiyear seaice left to do this anyway and it won't make any differency to the overall outcome anyway, which is....
Encouraged by the anti-clockwise, low level Arctic atmospheric wind vortex (the low pressure system that is usually in place over the nth pole) the gulf-stream loop will accelerate, forming a mixing vortex (whirlpool), first sucking down any remaining surface meltwater pool to deep polar ocean, along a long circular front above the deep polar basin.
As this is happening the Gulf stream and Bering strait warm water inputs will accelerate dragging ever warmer water in, and the entire Arctic ocean near surface region will flood with warm high salinity water at up to 12C or even higher.
This will eliminate any chance of the arctic ocean refreezing in winter. And:
The average 12C temperatures of the upper layer of the polar ocean will be sending a big thermal pulse down through the East Siberian Arctic Shelf and other shallow submarine permafrosts in the arctic. This pulse propagating fast through liquid water in cracks and methane eruption vents. The hydrate layers containing over 1000 billion tons C of methane at the bottoms of these permafrosts will be destabilising, bottom up, when that thermal pulse pins them between itself and rising geothermal heat.
The ESAS and other Arctic shelf Methane Hydrate reefs will be fizzing like an alka-seltzer in a glass of warm water, and the wind-turbulated open water will mean lots of that methane getting into the atmosphere and spiking global warming.
As the sun has set for the north polar winter at this point, the northern Alaskan, Siberian, and Canadian tundras will cool rapidly as usual. But this time the warm surface of the polar ocean will be releasing water vapour and this warm low density air/water vapour mixture will rise, accelerating the polar low into a very deep arctic storm system, very likely far stronger than any we've ever seen.
This will erupt warm water vapour bearing air high into the troposphere, and stratosphere above the pole and this will suck in the cold air from over Alaskan, Siberian, and Canadian tundras, drawing in air from further south and causing heavy winter rainfall rather than light snowfall. (usually in winter polar highs are dominant and descending cold dry air from these flows out over the Alaskan, Siberian, and Canadian tundras).
The tundra permafrosts will now be drenched in large volume rainfalls. The warm lakes and bogs all over them will be drilling through the permafrost, and lots of the around 1700 billion tons C of organic carbon locked up in the land permafrost will be flooding into the Arctic Ocean from Siberia, Alaska and North Canada. And getting sucked down the polar plughole. Lots will be getting released into the air as methane and carbon dioxide, and spiking global warming.
The donut-shaped circulation pattern sitting like a crown over the Arctic circle will start drawing down stratospheric air from further south.
Sometime soon, very probably in the nest northern summer monsoon season...
-At this point the extra methane, ozone, water vapour, and the loss of sea ice reflecting sunlight back into space will together be producing about 3x present day global warming effect.
and...
The jetstreams that are formed by warm moist air rising from the equator, dumping that moisture as heavy tropical rain in the tropics usually descend in the subtropical desert belts that circle the globe. They like cogs intermeshing will connect with the polar donut, drawing the summer monsoon north over the subtropical desert belts and building rapidly to tropical rainfall levels over the worlds deserts.
The dry descending air from the equatorial and north polar origin tropospheric flows and jetstreams will turn the temporate zones of the northern hemisphere into deserts in one year.
The ex tundra boglands will start to dry out. Its been learnt that when you thaw and soak permafrost peats, waking up the frozen bacteria. Then drain them....
-Significant quantities of Nitrous Oxide (N2O) start being emitted. Another "super-greenhouse" gas, with its own special radiative absorption band.
-With even more water vapour, more methane, more N2O, more ozone being produced by the methane, less SO2 forming clouds because methane destroys it....
Global warming will start to spike very high.
What happens maybe very quickly now is that an equatorial origin jetstream will either detach from its mode of descending at the new temporate zone deserts and form a new anticyclone most probably over greenland, or the anticyclone from that jetstream will migrate north from the subpolar tundras over North Canada.
Either way this special anticyclone with a very big future, will winch its way around the polar low in the new easterly "tradewinds belt" where the tundras and boreal forests are now. It will probably end up over the Beaufort sea, north of Alaska and recruiting more stratospheric jetstreams of Equatorial origin, quickly grow in strength. It will start a new clockwise ocean surface vortex in the Beaufort sea region, and if any iceflows and cold meltwater are still trapped against the west coast of the Canadian Archipelago.....
They will get sucked into this new clockwise vortex and it will love feeding on them and growing just like in the first anticlockwise vortex described above.
The new polar super anticyclone will out compete the previous polar super cyclone by one by one recruiting all the equatorial and tropical origin jetstreams, and become a, for any relevance to us, permanent, extremely powerful anticyclone over the whole polar ocean.
The new clockwise polar ocean vortex will be accelerated by the clockwise anticyclonic low atmospheric vortex. There will likely be lots of Glacier calved icebergs from Greenland, stuck against the west coast of the Canadian Archipelago. It will love gobbling, melting, and feeding on those.
It will steal the deep subduction from, and outcompete and swallow the previous anticlockwise polar ocean vortex.
Powering up this vast whirlpool, will suck in ever increasing flows of Atlantic and Pacific water, flooding the Arctic ocean with more and more tropical water. It will shovel more and more warm surface water like a wedge into a new intermediate temperature, high salinity layer, building between the tidal mixed zone and the surface mixed layer .
This intermediate layer is said to be the mechanism that produces anoxic oceans in past super-greenhouse/ anoxic ocean events. And this will happen fast because....
The tundra permafrosts will be seasonal deserts, but much warmer now. In summer they will be drenched by tropical temperature and volume rainfalls, hammered by cold fronts, supercell storms and tornados spitting off the high lattitude Megacyclones. The warm lakes and bogs all over them will be drilling through the permafrost, and more of the around 1700 billion tons C of organic carbon currently locked up in the land permafrost will be flooding into the arctic ocean from Siberia, Alaska and Nth Canada. And getting sucked down the polar plughole. More methane and CO2 will be making it into the atmosphere
In winter the ex tundras will dry out. Releasing yet more N2O and CO2.
Global Warming will spike through the roof.
And...
The by now over 20 degrees Celsius temperatures of the upper layer of the polar ocean will be sending a massive thermal pulse down through the East Siberian Arctic Shelf (ESAS) and other shallow submarine permafrosts in the arctic. This pulse propagating fast through liquid water in cracks and methane eruption vents. The hydrate layers containing over 1000 billion tons C of methane at the bottoms of these permafrosts will destabilise fast, bottom up, when that thermal pulse hits them. Quite possible the pressure building up under these shelves, most particularly the ESAS will shatter them and release most of the hydrate methane, free methane, and undecomposed organic carbon, they are holding very fast indeed. Best estimate around 2750 billion tons C total in shallow submarine arctic permafrosts.
Kinda like a warm well shook champagne bottle when you pop the cork.
Lots of this methane will hit the atmosphere.
With even more water vapour, more methane, more N2O, more ozone being produced by the methane, less SO2 forming clouds because methane destroys it....
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| Ballpark Chart for near filling of all relevant Radiative Absorption bands |
We'll have a greenhouse effect like the earth has not seen before in its 4.5 billion years of existence.
What REALLY concerns me looking at this chart is how much it would take going from this point to the Tipping Point for the Venus syndrome.
The situation in this chart would lead to a lot more stratospheric water vapour feedback. That could start to run away until the equatorial oceans boil, and there's no stopping things from there.
Lots of methane will get sucked down the Arctic plughole into the new anoxic intermediate ocean layer.
Archer 2007 states that 1000 billion tons C of methane (and/or other dissolved organic carbon) is sufficient to remove all oxygen from the worlds oceans. That won't take long.
- The polar ocean vortex might eventually stop. The momentum in ocean circulation, both deep and in surface gyres, combined with wind driven surface currents won't let this happen fast.
- In maybe 300-1000yrs a second even larger methane release will occur, as the heat from the surface reaches the deep sea bed. The deep sea Methane hydrates are estimated as between 5000 and 78 000 billion tons C of methane. That will not be nice at all, but there may be nothing left but bacteria well before then anyhow.
- The tropical/subtropical origin MegaCyclones to polar Mega AntiCyclone jetstreams with low atmosphere return system will most probably stick around for at least 100 000 years.
- The previous anoxic supergreenhouse/anoxic ocean events did have stalled ocean circulation, and the only way that they could have had 27C polar ocean temps like they did is by the Equatorial-Polar jetstream circulation mode described above.
- The most serious previously, the end-permian had no polar basin, oceanic/ atmosphere circulation, turbine pump "beartrap" for the planetary eco-geosphere to put its foot in. Neither did the PETM and Elmo supergreenhouse/anoxic ocean events, the most serious of the last 100+ million years, the polar basin was landlocked for those.
- Never before could the earth have had as much polar permafrost methane and carbon as it does now.
If we don't act fast now all this could very well unfold unstoppably in the next year or two. Can't see it taking much longer than 10 or 20 at the most.
