Feedbacks in the Arctic

created by Sam Carana, part of AGU 2011 poster
The dangerous situation in the Arctic is depicted by the image on the right, showing that the Arctic is hit by three major developments, i.e. three kinds of warming:
- Global Warming
- Accelerated warming in the Arctic
- Runaway Global Warming

The blue rectangles depict events that feed these developments, in some cases over a number of other events. 

Where developments and events feed each other, these interactions are depicted by lines with the direction of the feed indicated by the arrow.

Such feeds can turn into self-reinforcing feedback loops, i.e. a development or event that feeds back into itself, either directly or over a number of other events. 

Two such self-reinforcing feedback loops are depicted in above image and they are also highlighted in the image on the right. 

Feedback loop #1 occurs where sea ice loss results in albedo changes that accelerate warming in the Arctic, closing the loop by causing further sea ice loss. 

Feedback loop #2 occurs where accelerated Arctic warming weakens methane stores, resulting in methane releases that further accelerate warming in the Arctic. 

In both cases, accelerated warming in the Arctic feeds events that in turn feed other events, eventually causing further acceleration of warming in the Arctic. 

There are further self-reinforcing feedback loops. The image below also pictures how another feedback loop occurs as accelerated warming in the Arctic alters the jet stream, resulting in more extreme weather, in particular heatwaves, that cause wildfires. These wildfires cause all kinds of emissions, including carbon dioxide, dust, soot, volatile organic compounds, methane and other ozone precursors. The greenhouse gases accelerate warming, while aerosols can have a particularly strong impact in the Arctic when they settle on land, snow and ice and cause albedo changes that further accelerate warming in the Arctic. Incomplete burning results in carbon monoxide, which depletes hydroxyl that could otherwise have broken down methane.

In addition, there can also interactions between feedback loops. As an example, changes to the jet stream can cause heatwaves that will speed up snow and ice decline.

Above images show how such feedbacks cause further acceleration of warming in the Arctic, eventually spiraling out of control and escalating into a third kind of warming, i.e. runaway global warming.

In above image, three red arrows depict three major developments, i.e. three kinds of warming, with some feedbacks highlighted in yellow. The image below depicts numerous such feedbacks. 

Further details about each of these feedbacks are given at the end of this post. Without effective and comprehensive action, these feedbacks will lead to runaway warming, i.e. abrupt climate change causing mass death and destruction, and resulting in extinction at massive scale, as depicted in the image below and as described in this post.

The threat that this constitutes to security of supply of food and fresh water is further described in this post and this post, each also pointing at the need for a comprehensive and effective action plan. Without such action, as said, the above three kinds of warming are threatening to lead to a fourth development, i.e. near-term mass extinction of many species including humans, as above image shows. Action recommended as part of the Climate Plan is described at the Action page.

Feedbacks in the Arctic

1. Albedo loss due to snow and ice retreat and further snow and ice decline
Albedo loss can occur due to several forms of sea ice decline, i.e. when sea ice retreats, when warming changes the texture of the ice, and when meltwater pools emerge on top of the ice. Global warming is accelerating in the Arctic, causing snow and ice decline that results in albedo loss and thus more sunlight being absorbed, further accelerating warming in the Arctic, in a self-reinforcing cycle. As the snow and ice cover declines, more sunlight gets absorbed both by the Arctic Ocean and on land, where it is causing permafrost to thaw further and ice to melt at greater depth. Deposits of soot etc. (i.e. black carbon, brown carbon, dust, algae and more), and vegetation changes on land can also contribute to albedo loss.

3. Vertical currents weaken
As sea ice decline weakens vertical currents in the Arctic Ocean, the seabed warms up faster.

4. Storms and heatwaves causing more vertical mixing of water
This can cause warm water from the top layer of open waters to reach the seabed.

5. Storms and heatwaves accelerating Arctic warming
Accelerated Arctic warming causes stronger storms, bringing more warm air into the Arctic and pushing more cold air out of the Arctic, which can combine with changes to the jet stream into an even stronger feedback (see #19). Furthermore, accelerated warming causes stronger heatwaves that cause more melting of snow and ice through the impact of direct sunlight (#18).

6. More storms, heatwaves and evaporation creating more open water and precipitation 
Extreme weather events such as storms can push sea ice out of the Arctic Ocean into the Atlantic Ocean, resulting in more open water. Storms can develop more easily over open water, as there will be more opportunity for evaporation. Such storms can batter the sea ice, and they can come with rain, further devastating the sea ice by speeding up melting and creating melt-pools on top of the ice with a low albedo. Further precipitation can occur in the form of rain or hail that make the sea ice even more slushy, while even snow falling on meltpools can quickly melt and cause such meltpools to grow wider, in a self-reinforcing cycle, since meltpools will absorb more sunlight than a surface of white snow and ice (see also feedback #25).

7. Waves and Wind
Extreme weather cause winds and higher waves that degrade sea ice, breaking the ice into pieces. This causes warm water to melt the ice not only from underneath, but also at the sides. Cracks in the sea ice also make the sides more exposed to waves and this can cause water to flood pieces of ice. This causes faster melting of the ice, resulting in more open water that further contributes to snow and ice decline, because as sea ice gets broken up into numerous pieces, these each act as sails, catching the wind and moving more easily with the winds, possibly all the way out of the Arctic Ocean.

8. Albedo loss due to waves
Waves causing more wavy waters, and more wavy water absorbs more sunlight. Flat water acts like a mirror, reflecting a lot of sunlight away from the ice; waves cause the water to absorb more sunlight.

9. Extreme weather causing fires, dust storms, growth of microbes and further sources of emissions 
Emission of greenhouse gases causes global warming which in turn leads to forest fires. The additional greenhouse gases associated with forest fires will directly contribute to further global warming. Furthermore, aerosols emitted by fires can also contribute to warming, in particular in the Artic where aerosols such as black and brown carbon settling on the snow and ice cover will cause strong abedo changes, while dust settling on snow and ice can additionally act as nutrient, especialy so in environments with a lack of nutrients but with plenty of water, thus strongly stimulating growth of algae and microbes that further contribute to greater absorption of sunlight. Additionally, aerosols can facilitate formation of clouds (as discussed under feedback #25), e.g. melting sea ice can cause more release of iodine into the atmosphere, seeding the growth of new clouds that trap longwave radiation that would otherwise go into space.

10. Open Doors (as Jet Stream gets more wavy, warm air moves into Arctic and cold air flows out)
Accelerated Arctic warming changes wind patterns, in particular the polar vortex and jet stream. As warming in the Arctic accelerates, the temperature difference between the North Pole and the Equator decreases, making the jet stream more wavy. Furthermore, stronger storms can hit the Arctic (feedback #5). This makes it easier for warm air to move into the Arctic and for cold air to move out of the Arctic, in turn further decreasing the temperature difference between the Equator and the North Pole, in a self-reinforcing feedback loop. Sam Carana once referred to this as: "It's like the door of the freezer is left open." 

11. Warmer Arctic waters
Global warming is felt most strongly at higher latitudes on the Northern Hemisphere and the Arctic Ocean is right at the top in the North. During the months June and July, insolation in the Arctic is higher than anywhere else on Earth. Furthermore, warm water is flowing into the Arctic Ocean from the North Pacific and the North Atlantic. Feedbacks that are contributing to further heat up the Arctic Ocean include the Gulf Stream warming up rapidly (feedback #15), storms (feedback #5 and #6) and heatwaves occurring over the Arctic Ocean (feedback #18) and resulting in warmer water from rivers ending up in the Arctic Ocean (feedback #24). As the seafloor of the Arctic Ocean warms up, heat can penetrate and destabilize sediments, causing methane releases (feedback #16).

12. Seismic activity
Retreat of ice and snow cover comes with isostatic rebound, which can trigger underwater earthquakes, shockwaves and landslides, in turn destabilizing methane hydrates.

13. Less sea ice forming
Sea ice can be prevented from forming, due to kinetic energy (bubbling) of methane as it rises in the water and enters the atmosphere.

14. Latent heat loss
Where ice disappears, the heat will no longer go into the process of melting the ice, and the heat will instead go into increasing water temperatures. The image shows the July 2020 ocean temperature anomaly on the Northern Hemisphere and the latent heat tipping point estimated to be 1°C above the 20th century average, threatening to soon reach the methane hydrates tipping point estimated to be 1.35°C above the 20th century average (feedback #16).

15. Warmer Gulf Stream
The Gulf Stream heats up due to emissions, and this can be made worse by extreme weather, resulting in even warmer water getting carried by the Gulf Stream into the Arctic Ocean, thus further accelerating warming in the Arctic and the extreme weather events that this contributes to. The push of increasingly warm water into the Arctic Ocean can also be amplified due to stronger storms over the North Atlantic. Furthermore, a lid of freshwater at the surface can deteriorate the situation (feedback #28).

16. Seafloor warming
As the seafloor of the Arctic Ocean warms up, heat can penetrate sediments, causing destabilization, resulting in methane releases

17. Methane expansion
As methane escapes from hydrates, it expands to 160 times its earlier volume. The shock resulting from such expansion can cause further hydrate destabilization.

18. Heatwaves causing snow and ice decline
Extreme weather is causing longer and more frequent and intense heatwaves, resulting in greater snow and ice decline. Changes to the polar vortex and jet stream can make things even worse (feedback #19.).

19. Changes to the polar vortex and jet stream causing more extreme weather events
Changes to the polar vortex and jet stream are causing more extreme weather events and such extreme weather events can trigger further feedbacks, including:
- storms causing greater vertical mixing of water (feedback #4)
- storms and heatwaves accelerating Arctic warming, in turn causing further extreme weather (feedback #5)
- storms and heatwaves increasing humidity in the Arctic (feedback #6)
- strong waves (feedback #7)
- heat waves triggering wildfires (feedback #9)
- jet stream becoming more wavy and reaching high latitudes, moving warm air into the Arctic (feedback #10, mechanism 1.)
- heatwaves causing Arctic seabed warming (feedback #11)
- heatwaves causing snow and ice decline (feedback #18)
- jet stream branching out more, as it - at times - gets colder on land in Winter, while sea surafce temperature rises (this feedback, i.e. #19, or mechanism 2.)

20. Seismic activity triggering earthquakes and landslides
Submarine volcano eruptions, earthquakes and associated shockwaves can in turn trigger further earthquakes, as well as submarine landslides, especially along fault lines that separate tectonic plates.

21. Temperature swings causing destabilization
Methane is present in the Greenland ice sheet in the form of hydrates and free gas. Huge temperature swings can hit areas over Greenland over the course of a few days, causing the ice to expand and contract, thus causing difference in pressure as well as temperature. The combined shock of wild pressure and temperature swings is causing movement, friction and fractures in the ice, and this enables methane to rise to the surface and enter the atmosphere.

22. More plankton
A study by Park et al, May 12, 2015, concludes that the biogeophysical effect of future phytoplankton changes amplifies Arctic warming by 20%. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further.

23. Emissivity change
Feldman et al, Nov 18, 2014, found that open oceans are much less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum. The research team used a computer model that showed that open oceans hold more far-infrared energy than sea ice, resulting in warmer oceans, melting sea ice, and a 2°C rise in the polar climate after 25-year run.

24. Rivers heating up the Arctic Ocean 
Heatwaves over North America and Siberia can cause huge amounts of warm water to enter the Arctic Ocean via rivers. The image below shows ocean surface temperatures, with very high anomalies showing up where water from rivers flows into the Arctic Ocean.

25. Water vapor and clouds
Two feedbacks are related, i.e. the water vapor feedback and cloud feedbacks. A specific clouds feedback is discussed at feedback #30. 

The atmosphere can be expected to carry more water vapor as temperatures rise, as discussed in this study and this post. Since water vapor is a potent greenhouse gas, more water vapor in the atmosphere will contribute to global warming. More evaporation also brings more heat into the atmosphere, as illustrated by the image on the right, and more heat will also be transferred to the atmosphere as the area of open water increases in the Arctic Ocean.

Clouds can on the one hand reflect sunlight back into space, but on the other hand they can also trap heat and reflect heat back to Earth that would otherwise be radiated out into space. Studies such as by Dessler and by Sherwood et al. conclude that the net result of more clouds is that this will likely to contribute to global warming. See also feedbacks #27 and #29.

This feedback applies especially to the Arctic. Clouds cause more heat to remain trapped and this occurs all year long, while the impact of clouds reflecting more sunlight back into space depends on the season and doesn't make much difference where in the Arctic there is snow and ice, since there is little albedo difference between the top of clouds and the snow and ice cover.

Of particular interest is also the clouds tipping point that starts to occur at 1,200 ppm CO₂e and results in a global temperature rise of eight degrees Celsius (8°C or 14.4°F), as discussed under feedback #30 and in this post.

26. Salinity
Evaporation rates are higher over fresh water surfaces than over saline water surfaces. This, in combination with the higher temperature of river water flowing into the Arctic Ocean, will lead to more evaporation and thus more rain, which in turn results in warm rainwater pools on top of the sea ice, speeding up its demise.

27. More open water in the Arctic contributes to more severe storms and cirrus clouds
With more water vapor in the atmosphere and with more extreme weather events, storms can be expected to strike with greater intensity. This situation gets even worse as the Arctic Ocean loses its sea ice, with the additional open water adding to the water vapor in the atmosphere. This gives more opportunity for plumes above the anvils of severe storms to bring water vapor up into the stratosphere, contributing to the formation of cirrus clouds that trap a lot of heat that would otherwise be radiated away, from Earth into space.

28. Cold freshwater lid on the North Atlantic

Melting of sea ice and glaciers and thawing of the permafrost results in meltwater accumulating in the North Atlantic, where it forms a cold freshwater lid on top of the water. This lid grows further due to more rain falling on top of this lid. This results in less evaporation and transfer of heat from the North Atlantic to the atmosphere, and more ocean heat getting carried by the Gulf Stream underneath the sea surface into the Arctic Ocean.
This is a self-reinforcing feedback loop, as also described in post such as at:

29. Oceans take up less heat
Warmer water tends to form a layer at the surface that does not mix well with the water underneath, as discussed here. Stratification reduces the capability of oceans to take up heat from the atmosphere, thus speeding up warming of the atmosphere. This is a global phenomenon, but it can hit northern latitudes particularly hard as they are warming up very rapidly. This is depicted in the image on the right (pink blocks bottom right)

Many feedbacks can also combine and amplify each other. The image on the right also depicts this (pink blocks top right), showing how stronger storms can push more heat into the Arctic Ocean. At the same time, as the area of open water increases in the Arctic Ocean, more heat gets released into the atmosphere, resulting in a warmer atmosphere with more water vapor and clouds (feedback #25). Another danger is that extra heat will reach the seafloor of the Arctic Ocean where it can destabilize methane hydrates and trigger huge releases of methane into the atmosphere (feedback #4).

30. Clouds feedback above 1200 ppm CO₂e
A specific clouds feedback occurs when a tipping point of 1,200 ppm CO₂e gets crossed and marine stratus clouds start to disappear, resulting in an additional global heating of eight degrees Celsius (8°C or 14.4°F). While this is also a global feedback, it can hit the Arctic very strongly, given the size of the feedback (8°C) and given how much feedbacks in the Arctic can contribute to this tipping point getting reached.  


  1. The Climate Plan calls for comprehensive action through multiple lines of action implemented across the world and in parallel, through effective policies such as local feebates. The Climate Plan calls for a global commitment to act, combined with implementation that is preferably local. In other words, while the Climate Plan calls for a global commitment to take comprehensive and effective action to reduce the danger of catastrophic climate change, and while it recommends specific policies and approaches how best to achieve this, it invites local communities to decide what each works best for them, provided they do indeed make the progress necessary to reach agreed targets. This makes that the Climate Plan optimizes flexibility for local communities and optimizes local job and investment opportunities.

    Click for more on multiple lines of action, on recommended policies, and on the advantages of feebates.

    1. how can I be the only one reading this one thing sam I can tell you for sure is down here in Ft lauderdale this October the king tide was the highest not only my self but about 20 of my customers that have lived on the water canals or Intracoastal it was the highest they have ever seen it be intresting this october

  2. Feebates are nice in future. what we need now is $ to pay for physical action ($1/ton GHG would raise $37 trillion (in year 2016) — satellite shades, damming and cooling rivers as much as possible. Navies will be very useful.
    Compress and then chill air, then bubble it through surface water to make white surface-insulated ice. The ice might melt fairly quickly, but will reflect sun's energy until it does. Arctic ocean is layered; the heat from chilling compressed air can be partly dumped in a deeper layer (though not bottom). Or, in winter, hot air can be chimneyed high into the atmosphere. Water clouds heat, but ice clouds cool. In summer, fog might slow melting.
    Methane is a heavy gas, so low spots can collect it when wind is still, and it's easy to collect it from ponds — float a simple layer of plastic, but not big enough to deny oxygen to water life.

  3. This is like a patient with with a massive infection that has caused a fever, but we are only treating the fever. The earths' immune system is going into overdrive to rid itself of the excess heat, but just the arctic can't bring it down so it has accessed the antarctic via the jet stream to help. I think we will see 200+ sea level rise soon and who knows what from there.

  4. Further discussions are at: