Amplifying Feedback
Eight feedbacks driving global heating
Global heating is causing more global heating.
Here are nine “amplifying feedbacks” driving this heating: Each feedback is a “self-reinforcing, circular chain of cause-and-effect”, like this “permafrost feedback cycle”.
The permafrost feedback
| Higher air temperatures | More melting of permafrost | |
| More greenhouse heating | More methane & CO2 in the air |
If this feedback dominated, we would see:
- higher air temperatures, causing
- more melting of permafrost (ice containing frozen plant & animal matter), causing
- more decay of thawing organic matter, releasing
- more carbon dioxide & methane into the atmosphere, causing
- more greenhouse heating, which closes the cycle by causing
- higher air temperatures.
This permafrost feedback is dangerous as permafrost contains vast amounts of carbon: about 1.6 times more than our atmosphere.
It’s concerning that measurements show increases in every element of this feedback:
- global air temperatures are rising,
- permafrost temperatures deep within measurement boreholes are increasing, showing that permafrost melting is also increasing,
- atmospheric carbon dioxide is surging, and
- atmospheric methane is soaring.
These increases show that the permafrost feedback is active and may already be self-sustaining and unstoppable. We cannot tell if it’s self-perpetuating now because it is supported by:
- human emissions of carbon dioxide and methane, &
- other feedback cycles, which are also increasing global temperatures. (I briefly describe seven more example feedback cycles below.)
Humans are playing with fire by continuing to fuel these feedback cycles, and the critical question is, can humans stop this dangerous amplification of global heating?
For more on methane, see the methane feedback cycle on this website.
The ice cover feedback
| Higher air temperatures | Less ice cover | |
| * | Less sunlight reflection & more absorption |
This dynamic is reversible and could amplify cooling; see below.
See The dwindling Arctic sea ice on this website.
These causal linkages are tendencies
The cause-and-effect linkages in these feedbacks are tendencies or likely outcomes. External events often break the links in these feedback cycles, preventing the dominance of the feedback. For example, with “less ice cover”, the Arctic would normally “absorb more heat from the sun”, however, after a volcanic eruption, volcanic ash could reduce the sunlight reaching the Arctic, and the Arctic would NOT “absorb more heat”.
The water vapour feedback
This feedback is powerful as:
- water vapour is a potent greenhouse gas,
- there is more water vapour in our atmosphere than any other greenhouse gas, and
- this feedback operates fast because when you change the air temperature, you rapidly change the amount of water vapour in the air.
| Higher air temperatures | (1) More evaporation & (2) Warmer air can hold more water vapour | |
| More greenhouse heating | More water vapour in the air |
If this feedback dominated, we would see:
- higher global air temperatures, leading to
- (1) more water evaporating from oceans, and (2) the air being able to hold more water vapour, causing
- more water vapour in the air, causing
- more greenhouse heating of the atmosphere, causing
- higher air temperatures.
This cycle is reversible as global cooling would reduce water vapour in the atmosphere – but we are far from seeing any global cooling.
(Climate Change: Now or Never: New Scientist: 24 Apr 2021: page 37).
The phytoplankton feedback
| Higher air temperatures | More ocean surface heating | |
| More carbon dioxide in the air | Less nutrient up-welling | |
| Less photosynthesis & Less carbon sinking to the ocean floor | Reduced phytoplankton population |
See the heating of the ocean surface and the phytoplankton feedback cycle on this website.
The ocean CO2 feedback
| Higher temperatures | Higher ocean temperatures | |
| More CO2 in the atmosphere | Ocean can hold less CO2 |
See section “Ocean CO2 feedback” on the “Temperature & CO2” page on this site websites
The forest fire feedback
| Higher air temperatures | More heat & drought | |
| More carbon dioxide in the air | More forest fires |
See fires intensifying climate change on this website
The ice-darkening feedback
| Higher air temperatures | More melting of the ice sheet surface | |
| Less sunlight reflection | More dark matter on the ice surface |
If this feedback dominated, we would see:
- higher global temperatures cause
- more ice sheet melting, which exposes
- more dark matter on the ice surface, like ash from distant bush-fires that was buried in the glacier and is now on the ice surface, which causes
- the ice sheet to reflect less sunlight back into space, which closes the cycle by causing
- higher global temperatures.
The glacier altitude feedback
| More glacial surface melting | A drop in the altitude of the glacier surface | |
| * | A rise in average temperature at the glacier surface |
This feedback occurs because the average temperature at the top of a mountain is lower than at sea level – and this is relevant because we have some deep ice sheets, e.g., up to 4.9 kilometres deep in Antarctica.
See Glaciers in Retreat on this website.
The populist politics feedback
| Higher air temperatures | More extreme weather | |
| Less climate action | More conflict over land, water, food & housing | |
| More populist politics | More migration |
See right-wing populism feedback on this website.
Feedback that could limit global heating
The Arctic cooling feedback
The above “Arctic heating feedback” is reversible. It would become the “Arctic cooling feedback” and amplify cooling if cooling occurred.
| Lower air temperatures | More sea-ice cover | |
| * | More reflection & less absorption of sunlight |
The current exceptionally high level of greenhouse gases in our atmosphere means that we are unlikely to see any global cooling, so we are unlikely to see any amplification of global cooling.
Other global heating feedback cycles are also reversible, e.g., the water vapour feedback. Some feedback cycles are not reversible, e.g., the methane release feedback.
The amplification of climate action
Here is a feedback cycle that could amplify climate action in Australia and thereby contribute to limiting global heating.
 | More popularity for the superpower vision |  |
 |  | |
| More benefits |  | More progress toward the vision |
In this feedback:
- the increasing popularity of the vision of “Australia as a renewable energy superpower” tends to
- increase progress towards that vision, which tends to
- increase the resulting benefits, which tends to close the cycle by
- further increasing the popularity of the superpower vision.
Focusing on the feedback cycles that amplify global heating can be demoralising. It can be more energising to focus on positives, like this “amplification of climate action feedback”, which could propel Australia towards an attractive future. For more on this, see:
- The amplifying feedback cycle of vision, progress & benefit on this website, and
- Australia’s progress towards being a renewable energy superpower on this website.
No effective resistance to the current heating
James Lovelock (“The Revenge of Gaia”: 2006: page 35) writes that the observed rate of global warming is a grave concern. This rate suggests that no global climate dynamic will effectively resist the current warming and limit temperature increases to keep an environment safe for life as we know it.
Lovelock points out that the levels of methane and CO2 in the atmosphere in 2006 were comparable to those caused by natural releases of these gases fifty-five million years ago. At this time, temperatures rose between 5 and 8 degrees C, with consequences lasting 200,000 years.
There is no evidence of a climate dynamic emerging to limit temperature increases.
The danger of global heating amplification
Feedback cycles can produce exponentially increasing phenomena, e.g., the feedback you often get when a person is talking into a megaphone, and a slight hum rapidly turns into a painful shriek. Also, the various climate feedbacks reinforce each other, each adding to the heating and threatening our nurturing climate. So, these global heating feedback cycles threaten self-perpetuating, exponential increases in global temperatures. A critical danger is that:
- one feedback increasing global temperatures becomes dominant, leading to a cascade of similar feedbacks becoming dominant,
- these self-perpetuating dynamics increase global temperatures with increasing rapidity,
- the heating releases vast amounts of greenhouse gases like carbon dioxide and methane from sources like forest fires and the thawing of permafrost,
- humans cannot counter this heating as (1) stopping the use of fossil fuels only stops one source of carbon dioxide but does not decrease the levels of greenhouse gases in the atmosphere, and (2) geoengineering will not match the global scale of the many heating feedbacks, &
- our nurturing environment disappears.
We have co-evolved with our climate, so our current climate system suits human beings and the rich diversity of life on our planet. We must protect our climate system because global heating threatens our current climate, the global economy, political stability, human health, and the environment.
Systems theory & feedback
Feedback: A well-established concept
Feedback is a long-established concept that is a central part of “Systems Theory”. You may know about amplifying feedback under other names, like:
- Positive feedback cycles
- Positive feedback loops
- Self-amplifying feedback
- Vicious cycles
- Virtuous loops, or
- “Deviation amplifying mutual causal processes”. Maruyama used this term in his revolutionary 1963 article on feedback. (Maruyama: 1963: The Second Cybernetics: Deviation Amplifying Mutual Causal Processes)
Sound amplification systems & feedback
Here are some amplifying feedback examples that do not include climate change.
When a person speaks into a microphone with an amplifier and loudspeaker, they can kick off a soft hum, a sound that rapidly escalates into that painful, ear-piercing shriek called “feedback”. Here is an amplifying feedback cycle showing this process:
| Louder microphone input | |
| | |
| Louder loudspeaker output | | Amplification |
Destructive feedback: Road pothole formation
“A stitch in time saves nine”. This old saying is about stopping amplifying feedback from escalating problems and preventing more damage. Amplifying feedback can destroy things. For example, when a road develops a slight pothole, cars hit the pothole and make it bigger.
|  | |
| The pothole gets bigger. | Cars hit the pothole harder & more often. | |
 | |  |
Creative feedback: the emergence of a new interest
Amplifying feedback can also create new things of value. For example, when a person becomes interested in rocks at a beach, later they can read and develop expertise or even become a geologist.
| | |
| More fascination with a subject | More knowledge about the subject | |
| | |
Amplifying feedback & Chaos theory
Amplifying feedback offers an understanding of the “chaos theory” concept of the “butterfly effect”.
The butterfly effect puts forward the improbable example of something tiny causing something massive, i.e., the flap of a butterfly’s wing in Brazil causing a tornado in Texas. It is a way of announcing that systems can be super-sensitive in some regions and times so that something tiny can lead to something large. The butterfly effect accurately suggests that our world does not run predictably like clockwork. For example, a chance meeting or an unfortunate stumble can change people’s lives. Science used to regard the movement of the planets around the sun as predictable, but in the long term, even our planets are unpredictable.
When you use a microphone and get feedback, it’s hard to identify what triggers that shriek. Amplifying feedback often begins with an unnoticeable small change, and a repeating sequence of events amplifies this small initial change. Amplifying feedback can cause massive change, as suggested by the butterfly effect.
(Understanding the butterfly effect: American Scientist)
Negative Feedback
While amplifying feedback cycles tend to change systems, negative feedback prevents change. See the above Maruyama article or Wikipedia.
Site name: Feedback Reigns
The importance of “amplifying feedback cycles” led to this website’s name: “Feedback Reigns”.
External Links re feedback
- The Second Cybernetics: Deviation Amplifying Mutual Causal Processes: Maruyama: 1968
- The Fifth Discipline: The Art and Practice of the Learning Organisation: Peter Senge: 1990
- Climate Change Feedbacks: 10-minute video: UK Meteorology Office
- Feedback loops point to a very hot 21st Century: Science Daily, 6 May 2006
- “Initial Drivers of Climate Change”, “Climate Feedbacks”, and “Tipping Points“: NASA
- Greenland Reels: Climate Disrupting Feedbacks Have Begun: Truth-Out: 5/3/2015
Related pages on this site
The physics of tipping points and amplifying feedback
Updated: 4 October 2023