Clouds Tipping Point

Clouds Tipping Point

The PBS Terra video below features the clouds tipping point, as also discussed in a recent post at the ArcticNews group.  

The video mentions the 2019 analysis by Tapio Schneider that stratocumulus cloud decks become unstable and break up into scattered clouds when CO₂ levels rise above 1200 ppm, resulting in an abrupt additional temperature rise of 8°C (14°F), as discussed at the Clouds Tipping Point page. 

The SSP5-8.5 pathway (Shared Socioeconomic Pathway, used by the IPCC), corresponding with a radiative forcing of 8.5 W/m⁻² in 2100, projects CO₂ concentration rises to levels as high 2206.4 ppm in the year 2250, i.e. well above 1200 ppm, as illustrated by the image below, from a 2020 study led by Malte Meinshausen. So, how much temperature rise could this cause? 

SSP5-8.5 is often said to be a "worst-case" scenario, yet current developments may even exceed SSP5-8.5 projections, as discussed in an earlier post. The image below features in IPCC AR6 WG1 SPM. The total warming of the IPCC pathways (panel b) is dominated by CO₂ emissions that keep growing steadily in SSP5-8.5, while the maximum temperature rise stays well below 6°C. 

Is this in conflict with the additional 8°C rise when the Clouds Tipping Point gets crossed? Let's analyze this. Importantly, the Clouds Tipping Points is at 1200 CO₂e, with contributions not only from CO₂, but also from methane, water vapor, etc.  

[ from earlier post ]

Reductions in methane emissions can strongly reduce the total CO₂e, given methane's high Global Warming Potential (GWP). Could reductions in methane emissions keep the total CO₂e below 1200 ppm? In both the SSP1-1.9 and SSP1-2.6 pathways, methane emissions would fall after 2015, and methane emissions would also fall over time for SSP2-4.5, in which 2°C does get crossed, and for SSP5-8.5.

So, if the impact of methane is high and if methane emissions would strongly decline, could it be possible that 1200 CO₂e wouldn't get crossed? Conversely though, if growth in methane emissions continues, this can strongly push up the total CO₂e, as occurs in SSP3-7.0, but in that pathway there are less CO₂ emissions and less reductions in sulfur dioxide emissions.

Anyway, what happened after 2015, the year when politicians pledged at the Paris Agreement to take efforts to limit the temperature rise to 1.5°C? Lo and behold, methane emissions kept rising after 2015! There was record growth in methane concentrations in 2021, after which there was a bit of a slowdown in growth during the following years, but growth in methane concentration picked up pace again recently, as illustrated by the image below, from an earlier post.

So, it appears again that SSP5-8.5 isn't the "worst-case scenario" in more than one way. An even worse case scenario would see strong emissions of both CO₂ and methane. Once more, it appears that politicians and collaborating scientists have been downplaying the temperature rise that is about to unfold. The IPCC produced a special report, called Global Warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways and the report's pathways don't seem to make sense in many ways, as also discussed in an earlier post. 

The image below is also from that earlier post. The image depicts an alternative pathway in which methane concentrations grow in line with the added magenta-colored trend that points at methane more than doubling by 2043. Such developments should have been included, at least in the margin of uncertainty, i.e. as a potential development. 

The above text and images describe and depict horrendous dangers, yet the IPCC remains silent, refusing to warn people about the dangers and refusing to recommend effective policy pathways. Note that methane is only one of the contributors to a potentially horrific rise in temperature in the Arctic.

Such developments were discussed in a 2021 post that featured the image below, with the caption that a 5 Gt burst of seafloor methane would double the methane in the atmosphere and could instantly raise CO₂e level to above 1200 ppm, thus triggering the cloud feedback (panel top right). Even with far less methane, levels of further pollutants could rise and feedbacks could strengthen, while sulfate cooling could end, and a 18.44°C rise (from pre-industrial) could occur by 2026 (left panel).

How appropriate is the use of a multiplier of 200 to convert the impact of methane in parts per million (ppm) methane to ppm CO₂e? After all, carbon dioxide equivalence (CO₂e) was introduced by politicians in the Kyoto Protocol, which was adopted in 1997 and uses a Global Warming Potential (GWP) of greenhouse gases over a 100-year horizon to calculate their carbon dioxide equivalence. Is GWP a tool behind specific politics? How much sense does it make to calculate methane's GWP over 100 years, given that methane's atmospheric perturbation lifetime is less than 12 years and methane has its highest impact immediately after it enters the atmosphere? What multiplier should be used to calculate the impact of an extra 5 Gt of methane? 

The image on the right, from an earlier post, shows trends based on IPCC AR6 GWP values pointing at a GWP for methane of 150 for a 9-year horizon and pointing at an even higher GWP for a shorter horizon. 

A short horizon makes sense when calculating the immediate impact of, say, a 5 Gt burst of methane from the seafloor of the Arctic Ocean.

There are other ways to calculate the impact, e.g. one can also look at radiative forcing. It makes sense to also take into account the indirect impact of methane, as done in the image below. The image conceptually dates back to 2019 when the analysis by Tapio Schneider et al. was published, hence the use of radiative forcing from the IPCC AR5 WG1 SPM report that was published in 2013.

The image below shows three blocks each of about 400 ppm CO₂e, adding up to 1200 ppm CO₂e. The bottom block (purple) represents the CO₂ present in the atmosphere, i.e. on May 9, 2013, CO₂ surpassed 400 ppm at Mauna Loa. It is noted that extra CO₂ has less impact as its abundance grows, whereas extra CH₄ has a stronger impact.

The block in the middle (dark red) shows the methane already in the atmosphere, with the note that IPCC AR5 gives CH₄ an impact of 0.97 W/m⁻² (see top of image), or 57.74% of the impact of about 400 ppm CO₂. Yet, the impact of methane could rise to 400 ppm CO₂e, for reasons described in the following paragraph. 

The spectral band where most heat is trapped by CO₂ is more saturated than the band where most heat is trapped by CH₄. The impact of additional CH₄ will increase as its abundance grows, whereas the impact of additional CO₂ will decrease as abundance grows. Abrupt eruptions of 5 Gt of seafloor CH₄ will cause hydroxyl depletion. Since there is already very little hydroxyl present over the Arctic, large eruptions of CH₄ from the seafloor of the Arctic Ocean would strongly increase the lifetime of CH₄ there, trigger feedbacks and increase its global warming impact. The warming impact of an extra 5 Gt of CH₄ could therefore approach the impact of the CO₂ that was in the atmosphere on May 9, 2013, and this would not only apply to the methane that is added by such eruptions, but it would also increase the impact of CH₄ already present in the atmosphere. 

The block of 400 ppm CO₂e at the top of the bar (red) represents an extra 5 Gt of CH₄ resulting from a burst of methane erupting from the seafloor of the Arctic Ocean. Some of the methane arising from the seafloor will be broken down in the water by microbes, but many of the seas in the Arctic Ocean are very shallow and when large amounts of methane erupt in the form of plumes and move at high speed through the water column, only a small part of the methane can be broken down on its way up through the water column. Anyway, the point is that 5 Gt of methane abruptly entering the atmosphere could have an immediate impact of 400 ppm CO₂e which would also raise the impact of the block of existing CH₄ to 400 ppm CO₂e. 

Jointly, the three blocks each of 400 ppm CO₂e add up to 1200 ppm CO₂e, i.e. the tipping point where stratocumulus decks start to disappear abruptly, resulting in an additional temperature rise of 8°C. Even when CO₂ levels are lowered again after the stratocumulus breakup, the stratocumulus decks only reform once the CO₂ levels drop below 300 ppm, as discussed at the Clouds Tipping Point page.

Historic growth in methane concentrations

Historic records could have given a stronger warning than the IPCC pathways. Methane has historically risen faster than CO₂. As illustrated by the image on the right, based on IPCC and WMO data, and from an earlier post, methane in 2024 was 266% of what it was in 1750, whereas CO₂ in 2024 was 152% of what it was in 1750. 

In fact, the rise in emission by people had already started well before 1750. Thousands of years ago emissions started to grow in agriculture, herding of animals and associated deforestation, as illustrated by the combination image below, adopted from Ruddiman et al. (2015). 

Thousands of years ago, methane concentrations were as low as 550 ppb, while CO₂ concentrations were as low as 260 ppm. So, methane in 2024 was 335% of what it was thousands of years ago, whereas CO₂ in 2024 was 163% of what it was thousands of years ago. In other words, methane concentrations have risen twice as fast as CO₂ concentrations.  

[ from earlier post ]

As discussed in earlier posts such as this one and this one, the IPCC keeps downplaying the dangers that we're facing, and one way the IPCC does so is by manipulating the outlook of CO₂, methane and sulfur dioxide emissions. Another way is to downplay the historic temperature rise, which is important, since a larger historic rise would also come with more water vapor in the air, a powerful greenhouse gas that causes a self-amplifying feedback further increasing the temperature rise. 

Existential threat

So, are we facing an existential threat? The speed at which temperatures are rising is unprecedented in the historic record. Historically, people have been pushing up the temperature for thousands of years, due to deforestation and further activities by people.  

[ image from Tierney et al (2025), also discussed at ArcticNews group ]

Activities by people have been pushing up the temperature from a genuinely pre-industrial base for thousands of years, maybe by more than 2°C, as illustrated by the bottom panels on the image below.

The above image, from an earlier post, illustrates that, in the Northern Hemisphere, 2025 was the third year in a row with temperature anomalies more than 1.5°C above 1951-1980 and much more when compared to pre-industrial, as discussed in the inset. Note also that El Niño wasn't elevating temperatures in 2025.

[ from the post When will humans go extinct? ]

A 3°C rise constitutes an important threshold, since humans will likely go extinct with such a rise. The top panel in the above image shows a potential 10°C rise, while we may already be more than 2°C above pre-industrial. A further 1°C can quickly be added due to the move from a La Niña into the next El Niño, albedo loss and further feedbacks such as extra water vapor as temperatures rise, seafloor methane eruptions, fires, collapse of society causing abrupt termination of the sulfur aerosol masking effect. If society collapses, greenhouse gases with a high GWP and long lifetime could be emitted as substances leak from warehouses, waste dump fires, etc. Furthermore, aerosols from sulfur dioxide could fall out of the air in a matter of weeks, all contributing to a rapid temperature rise. 

The IPCC appears to have painted scenarios that are shrouded in dubious politics, rather than relating to best-available science and a realistic outlook on future developments. As an example, the speed in the projected decline in aerosols from sulfur dioxide in the various Shared Socioeconomic Pathways can make a huge difference. 

How  much could temperatures rise? James Hansen points out that equilibrium global warming for today’s GHG amount is 10°C, which is reduced to 8°C by today’s human-made aerosols. This 10°C rise is held back by oceans and ice acting as a buffer and by aerosols. How long would it take for a 10°C rise to unfold? Heat sinks could abruptly turn into sources, e.g. due to sea ice loss and changes in wind, soil and oceans such as ocean stratification. 

Keep in mind that concentrations of greenhouse gases are still rising. Also keep in mind that the land-only temperature rise is higher than the global rise and most people live on land. Many people also live in areas where the rise is stronger than average during heatwaves and due to the Urban Heat Island effect. The conclusion is that humans are functionally extinct if temperatures keep rising. Importantly, changes in biodiversity can have terrible consequences, and much of this is ignored by the IPCC. 

Biodiversity collapse

   [ from: When Will We Die? ]

A 2025 analysis by David Fastivich et al. finds that, historically, vegetation responded at timescales from hundreds to tens of thousands of years, but not at timescales shorter than about 150 years. It takes centuries for tree populations to adapt - far too slow to keep pace with today’s rapidly warming world. Vegetation depends on the presence of a lot of things including healthy soil, microbes, moisture, nutrients and habitat.

A 2025 analysis led by Thiago Gonçalves-Souza concludes that species turnover does not rescue biodiversity in fragmented landscapes.

A 2018 study by Strona & Bradshaw indicates that most life on Earth will disappear with a 5°C rise (see box on the right). Humans, who depend on a lot of other species, will likely go extinct with a 3°C, as discussed in the earlier post When Will We Die?

Terrestrial vertebrates are more in danger than many other species, as they depend on numerous other species for food. Humans are terrestrial vertebrates and humans are large warm-blooded mammals with high metabolic rates, thus requiring more food and habitat. It also takes humans many years to reach maturity. Humans have become addicted to processed food, fossil fuels, plastic, etc. Furthermore, humans require large amounts of fresh water, including for sweating when temperatures rise. A 3°C rise may therefore suffice to cause humans to go extinct, as discussed in earlier posts such as this one and this one. 

A 2025 analysis led by Joseph Williamson concludes that many species that live together appear to share remarkably similar thermal limits. That is to say, individuals of different species can tolerate temperatures up to similar points. This is deeply concerning as it suggests that, as ecosystems warm due to climate change, species will disappear from an ecosystem at the same time rather than gradually, resulting in sudden biodiversity loss. It also means that ecosystems may exhibit few symptoms of heat stress before a threshold of warming is passed and catastrophic losses occur. A 224 analysis by Michael Van Nuland et al. finds that tree symbioses with ectomycorrhizal fungi mean that they need to move together for successful migration. 

In the video below, Guy McPherson explains that forests cannot keep up with the speed at which temperatures are rising. 

Guy McPherson mentions the study by William Farfan-Rios et al. that finds that Amazonian and Andean tree communities are not tracking current climate warming. Further science snippets: The Amazon is also getting drier as deforestation shuts down atmospheric rivers. Thunderstorms are a major driver of tree death in tropical forests. Hot droughts cause catastrophic tree die-offs. Aboveground biomass in Australian tropical forests now a net carbon source.

Huge temperature rise

[ from the Extinction page ]

The image on the right illustrates how such dangers could be further amplified by the threat of war and collapse of centralized society. 

As people seek to occupy the last few habitable areas left, many people may stop showing up for work, resulting in a rapid loss of the aerosol masking effect, as industries that now co-emit cooling aerosols (such as sulfates) come to a grinding halt. As it becomes harder to obtain food and fuel for cooking and heating, and as the grid shuts down due to conflicts, many people may start collecting and burning more wood, decimating the forests that are left and resulting in more emissions that further speed up the temperature rise.

As temperatures rise, huge fires could also break out not only in forests, peatlands and grassland, but also in urban areas (including backyards, landfills and buildings, in particular warehouses containing flammable materials, chemicals and fluorinated gases), further contributing to more emissions that speed up the temperature rise.

As the likeliness of further accelerating warming, the severity of its impact, and the ubiquity and the imminence with which it will strike all become more clear and manifest—the more sobering it is that, while a mere 3°C rise may suffice to cause human extinction, a much larger temperature rise may unfold abruptly, as illustrated by the bar-chart on the right. 

The image below, from an earlier post, shows monthly data from May 2022 through May 2025, with a trend added that warns about 1200 parts per million (ppm) getting crossed in 2028.

As said, crossing the clouds tipping point at 1200 ppm CO₂ could - on its own - push temperatures up by 8°C globally, on top of the temperature rise caused by the forcing that resulted in the crossing of this tipping point. Moreover, the clouds tipping point is actually at 1200 ppm CO₂e (carbon dioxide equivalent), so when taking into account the impact of growth of other gases, strengthening feedbacks and further mechanisms, this tipping point could be crossed much earlier than in 2028, potentially as early as in 2026.

Methane in the atmosphere could be doubled within years if a trend unfolds as depicted in the image below, from an earlier post. A rapid rise is highlighted in the inset and reflected in the trend, which is based on January 2023-October 2024 methane data, as issued in February 2025.

[ Double the methane in March 2026? Image from earlier post, click on images to enlarge ]

A rise like the one depicted in the trend could eventuate as rising ocean heat destabilizes methane hydrates contained in sediments at the seafloor of the Arctic Ocean. The temperature rise in the Arctic would accelerate since the methane would initially have a huge temperature impact over the Arctic and cause depletion of hydroxyl, of which there is very little in the atmosphere over the Arctic in the first place. Such a rise in methane would also dramatically increase concentrations of ozone in the troposphere and concentrations of water vapor in the stratosphere. 

Climate Emergency Declaration

The situation is dire and unacceptably dangerous, and the precautionary principle necessitates rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.

Links

• Clouds feedback and tipping point  

https://arctic-news.blogspot.com/p/clouds-feedback.html

• Advances in Paleoclimate Data Assimilation - by Jessica Tierney et al. (2025) 

https://www.annualreviews.org/content/journals/10.1146/annurev-earth-032320-064209

discussed on Facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10163934412354679

• Coupled, decoupled, and abrupt responses of vegetation to climate across timescales - by David Fastivich et al. (2025) 

https://www.science.org/doi/10.1126/science.adr6700

discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10163832954534679

• Amazonian and Andean tree communities are not tracking current climate warming - by William Farfan-Rios et al. (2025) 
https://www.pnas.org/doi/10.1073/pnas.2425619122

• Clustered warming tolerances and the nonlinear risks of biodiversity loss on a warming planet - by Joseph Williamson et al. (2025) 
https://royalsocietypublishing.org/rstb/article/380/1917/20230321/109625/Clustered-warming-tolerances-and-the-nonlinear

• Climate mismatches with ectomycorrhizal fungi contribute to migration lag in North American tree range shifts - by Michael van Nuland et al. (2024) 
https://www.pnas.org/doi/10.1073/pnas.2308811121

discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10163832955574679

• Species turnover does not rescue biodiversity in fragmented landscapes - by Thiago Gonçalves-Souza et al. (2025)
https://www.nature.com/articles/s41586-025-08688-7
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10162452301209679

• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html

Global sea ice extent falling off chart

Global sea ice extent is falling off the chart, as illustrated by the image below.

[ click on images to enlarge ]

The National Snow & Ice Data Center (NSIDC) is one of the world's best-know archives for satellite data on sea ice.

In its recent news release, NSIDC notes that the difference between the 1981-2010 average global sea ice extent and the 2016 extent was over 4 million km² in mid-November 2016 (image on the right).

The fall in sea ice extent constitutes a huge amount of energy that is no longer reflected back into space and is instead absorbed by the ocean, the atmosphere and by the process of melting itself.

In line with earlier calculations by Professor Peter Wadhams, a 4 million km² sea ice decrease could equate to a radiative forcing of as much as 1.3 W/m². All this extra energy does not directly translate into a rise in temperature of the atmosphere, since a lot of energy has over the past few decades been absorbed by the ocean and has also gone into the process of melting itself. However, it now looks like the temperature of the atmosphere is catching up fast, as illustrated by the image below.

[ click on images to enlarge ]

On the right is a forecast by the European Centre for Medium-Range Weather Forecasts (ECMWF).

It shows that we've barely been in a La Niña, which typically makes the atmosphere cooler than it would otherwise have been.

Already now, another El Niño is on the way that could soon make it up to 2.5°C warmer than it is was late last year.

Global sea ice volume is also at record low, as illustrated by the image below on the right.

Arctic sea ice thickness hit a record low in November 2016 when thickness fell below 0.7 m or 2.3 ft.

As the ice gets thinner, the risk of collapse grows, as increasingly stronger winds and storms and stronger wave action can more easily break up thin sea ice, making it more vulnerable to melting and to get carried out of the Arctic Ocean by stronger cyclonic winds and stronger exit currents.

Disappearance of Arctic sea ice increases the risk of huge methane releases from the seafloor of the Arctic Ocean. The outlook is terrifying. As I calculated last year, surface temperatures of the atmosphere could rise by some 10°C or 18°F within a decade, i.e. by 2026.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Extinction
http://arctic-news.blogspot.com/p/extinction.html

• How much warming have humans caused?
http://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

Tipping Points

Aaron Franklin

By Aaron Franklin


Tipping point one: Complete global deglaciation. 

This looks like it happened in the last Interglacial 120 000 yrs ago.

The Arctic Sea ice went completely. Most if not all of Greenland and west Antarctic ice sheets went too. Theres 30m above current sea level ancient beaches all around the world proving that.

With recent observations of coastlines receding by Thermokarst/coastal erosion (wave action and warm water melt the coastal land permafrost layer, accelerated by thermokarst lakes drilling with warm water through the coastal tundra permafrost) in Siberia, Alaska, and Nth Canada by up to 200m, mostly in the last 10yrs, and accelerating...

Example of Coastal Thermokarst lakes on the East Siberian Arctic Shelf coastline:

https://maps.google.com/maps?hl=en&ll=71.063363,152.105713&spn=1.765191,10.821533&t=h&z=7

View Larger Map

Pan around, Zoom in, its quite scary.

I think its fair to say that most, if not all of the ESAS, and most of other arctic basin continental shelves may have been created by this process in that last interglacial.

International Bathymetric Chart of the Arctic Ocean - from: ibcao.org

Evidence for this is that there is only traces left of glacial channels carved into the edges of the continental shelves around Norway, Greenland, Nth Canadian Archipelago, and Svalbard.

Shelves in these places are flat, 40-100m below sealevel, flat, the glacial channels mostly filled with sediments from the eroded coasts. Some of this erosion has happened in the last 10 thousand years around Norway, Greenland, and to a lesser extent Nth Canadian Archipelago, and Svalbard.

But its unlikely that prior to mans intervention, that much coastal permafrost got melted in the ESAS, because the surface seawater stayed -1.8C to 0C probably up until the last 30 years.

The reason the arctic shelves, and particularly the ESAS are the most dangerous pieces of geology on the planet is, that while they have been frozen for at least the last 90 000 years. They have been collecting methane produced by baking oil shale layers, subducted under the edges of the continents, mostly as water-methane crystal hydrates in their bottom layers.

If this happens under land permafrost, its more porous and there isn't enough pressure for hydrates to be stable. Under not frozen submarine shelves the temperature isn't low enough for hydrate stability.

Now, Earths vulnerable Carbon stores are:

Carbon in the Arctic

ESAS:
500 Gton C organic
1000 Gton C hydrate
700 Gton C free methane
total: 2200 Gton C

+other submarine arctic permafrost:
2200/0.8=2750 Gton C

+1700Gt in land permafrost= 4450 Gton C

A large part of this is Vulnerable to being lost rapidly into the Ocean/Atmosphere system if the Arctic defrosts, polar ocean warms, heavy rainfalls hit the Tundras.

Carbon in soils and Living Biomass:

Total organic C in soil and living biomass is approx: 1000 Gton C living + 1500 Gton soil.

= 2500Gton C

A large part of this is Vulnerable to being lost rapidly into the Ocean/Atmosphere system if the Arctic defrosts, Global weather systems change, Rainforests and/or peat deposits burn, desertification and/or heavy rainfalls hit the Tropical, Temperate, Boreal forests.

So tha'ts the vulnerable surface Carbon stores. Total about 7000 billion tons of carbon.

There's never been this much in the history of planet earth, that we know of.

Carbon in Deep sea Clathrates:

estimates range from 5000 Gton C to 78000 Gton C

A large part of this is Vulnerable to being lost into the Ocean/Atmosphere system if the oceans warm a few degrees, reaching the bottom in a few hundred to a few thousand years, causing the stability to be lost.

There's never been this much in the history of planet Earth, that we know of.

Now if Mankind hadn't got in the way by dumping 500 Gton C of Organic carbon from soil and living biomass into the Ocean-Atmosphere system before the Industrial revolution, and most particularly by dumping a further 500 Gton C of fossil fuels there as well since, what might have happened is this:

The Arctic sea ice would have gone slowly, over a period of centuries, and the Arctic shelf methane would have fizzed off slow enough to be all converted into CO2, without raising methane and its product ozone levels in the atmosphere significantly.

The Weather patterns wouldn't have changed much so the tundras wouldn't have melted fast, and the prospect of heavy rain there wouldn't be looming. The ecosystems would have had time to shift the boreal forests north onto the tundras as they slowly got wetter. The frozen Tundra peats would have been stabilised by roots, and the tundra permafrost methane, would have fizzed off slowly, all safely converted to CO2 and a little organic carbon/nitrogen would have been decomposed into safe CO2 and soil Nitrates.

The Release of CO2 would have been slow enough for the biological ocean system to bury it on the sea bottom, the 300 year duration of carbonate/silicate weathering getting it on the way to safe limestones, and clays.

We probably would have been up for a hundred odd million years of no ice on the planet. Subduction techtonics around the polar shelves would have gradually broken off the ESAS etc, and a lot of the ex-permafrost peats, turning them thru submarine landslides into polar basin sediments. As that happened slowly, the carbon would have all been buried and turned to stone. The CO2 would have stayed high enough throughout this time to keep the planet ice free.

Eventually in maybe 100 million years the earth might have gone back into a glaciation.

Image from: http://upload.wikimedia.org/wikipedia/commons/f/f5/All_palaeotemps.png (click to enlarge)

Instead, Mankind got in the Way. 

Now we have today this:

Adapted by Aaron Franklin from image at Wikipedia - radiative forcing

This chart showing the present day situation, the effect of an extra 4.5 Gton C methane in the atmosphere, and the tipping point line for "super-greenhouse/Anoxic ocean" mass extinction events like the end Permian 252 million years ago, and the more recent PETM 56 million years ago. About 20 of those we know about in earths history. 

Unfortunately it doesn't stop there. 

It looks like Nature has conspired to set up a perfect Eco-Geospheric beartrap, that we have sprung by slamming together a WHOLE LOT of tipping points into such a short space of time that what we have probably done is created a perfect planetary environmental storm, and lined ourselves up for, in a few decades from now THIS:

And with water vapour feedback kicking in, the Megacyclones kicking vast quantities of warm moist air high into the stratosphere, warming it from -40C to well above Zero.... 

It doesn't look like stopping there. 

The good news though is that we have all the knowledge now, just in time, and all the tools to stop it quickly and relatively easily. Provided we act within the next few months. 

If we don't, We might have no chance whatsoever of stopping this cascade of tipping points.

The worst-case and - unfortunately - looking almost certain to happen scenario

Aaron Franklin

By 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....

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. 

I hope this explains to everyone the urgency and seriousness of the current situation, and why we need to act with overwhelming force to stop the arctic sea-ice going this year.

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.