The biggest climate risk
The hotter it gets, the hotter it gets: some self-amplifying processes powering global heating. These processes are destroying our nurturing climate and threaten runaway heating. Also, some processes that could help reinstate our nurturing climate.
- The biggest climate risk
- The Arctic warming feedback loop
- These linkages are tendencies
- Feedback loops that could limit global heating
- Other global heating feedback loops
- The danger of global heating amplification
- No effective resistance to the current heating
- Feedback Loops
The Arctic warming feedback loop
|More global warming||More ice melt|
|More open water & more sunlight absorbed.||Less ice & less sunlight reflected.|
In the Arctic, warming is causing further warming. In this cycle:
- Global warming tends to increase temperatures in the Arctic and melt more ice.
- This tends to decrease the area covered by sea-ice and the sunlight reflected into space.
- This increases the area of darker coloured exposed ocean and the sunlight that is absorbed by the ocean.
- This tends to increase global warming, and the cycle repeats.
See The dwindling Arctic sea-ice on this website.
These linkages are tendencies
The linkages in these feedback loops are tendencies or likely outcomes. For example, when the area of reflective ice in the Arctic drops, this only tends to increase global heating; global temperatures could fall due to volcanic ash reducing the amount of sunlight reaching the earth.
Feedback loops that could limit global heating
Feedback loops amplifying global cooling
The above Arctic warming feedback loop is reversible.
|More global cooling||More sea-ice formation|
|Less open water & less sunlight absorbed.||More ice & more sunlight reflected.|
The current exceptionally high level of greenhouse gases in our atmosphere means that we are unlikely to see any global cooling soon, so we are unlikely to see any amplification of global cooling. However, if we do get cooling, this dynamic could help us cool the planet.
Some other global heating feedbacks are also reversible, and I will identify these below.
The amplification of climate action
Here is one feedback loop that could amplify climate action in Australia.
|More popularity for the superpower vision|
|More benefits||More progress towards the vision|
It can be energising to focus on an attractive future vision, the progress towards that vision and the resulting benefits, rather than the many feedback loops that amplify global heating.
- See The amplifying feedback loop of vision, progress & benefit on this website.
- See Australia’s progress towards being a renewable energy superpower on this website.
Now, here are other examples of feedback cycles that amplify global heating.
Other global heating feedback loops
The permafrost methane feedback loop
|More global heating||More melting of ice containing methane|
|More greenhouse gasses||More methane release|
This feedback is not reversible as global cooling will not remove methane from the air and trap it in permafrost.
See the methane feedback loop on this website.
The water vapour feedback loop
|More global heating||Air temperatures increase|
|More greenhouse gases||More water vapour in the atmosphere|
Warming increases water vapour in the atmosphere, and water vapour is a potent greenhouse gas.
(Climate Change: Now or Never: New Scientist: 24 April 2021: page 37).
This loop is reversible as global cooling would reduce water vapour in the atmosphere.
The phytoplankton feedback loop
|More global heating||More ocean surface warming|
|More carbon dioxide in the atmosphere||Less nutrient upwelling|
|Less photosynthesis||Reduced phytoplankton population|
See the warming of the ocean surface and the phytoplankton feedback loop on this website.
The forest fire feedback loop
|More climate change||Higher temperatures & more drought|
|More forest fires|
|More CO2 in the air||Release of CO2 and Less use of CO2 in photosynthesis|
See fires intensifying climate change on this website
The ice surface darkening feedback loop
|More global heating||More melting of the ice sheet surface|
|Less reflection of sunlight||More dark dust in the ice surface|
- Global heating tends to increase the melting at the surface of an ice sheet, e.g. the Greenland ice sheet.
- This tends to increase the amount of exposed dust on the ice’s surface, dust that originally fell onto the glacier and was buried by snow before becoming part of the ice sheet.
- This exposed dust will be less reflective than the ice and will increase sunlight absorption.
- This tends to increase global heating.
Glacier melt feedback loop
|More melting of the glacier||A drop in the altitude of the glacier surface|
|.||A rise in average temperature at the glacier surface|
See glaciers in retreat on this website.
Migration, Populism & Climate inaction feedback loop
|More global heating||More extreme weather|
|Less climate action||More social & political instability|
|More right-wing populism||More deprivation & migration|
See migration, right-wing populism, climate inaction feedback on this website.
The danger of global heating amplification
The risk of allowing our planet’s current heating to continue is that feedback cycles that amplify the current heating could produce run-away heating that would continue even if humans stopped burning all fossil fuels.
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 need to protect our climate system because global warming amplification threatens our current climate, the global economy, political stability, human health, and the environment.
When a loudspeaker goes into “feedback”, you can quickly turn it off. Unfortunately, the earth’s climate does not have an easily-flicked off-switch.
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, limit temperature increases, and retain an environment safe for life as we know it.
Lovelock (published in 2006) noted that the levels of methane and CO2 in the atmosphere 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.
We do not know whether a climate dynamic will emerge to limit temperature increases to a safe level. We do know of many amplifying feedback loops that could feed runaway climate change. They pose a real risk for the global economy, political stability, human health and our environment.
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 loops
- Self-amplifying feedback
- Vicious cycles
- Virtuous loops, or
- “Deviation amplifying mutual causal processes”. Maruyama used this term in his revolutionary 1968 article on feedback. (Maruyama: 1968: The Second Cybernetics: Deviation Amplifying Mutual Causal Processes)
Non-climate examples of amplifying feedback
A person speaks into a loudspeaker, which kicks off a soft hum, rapidly escalating into that ear-piercing shriek called feedback.
|Louder microphone input||Louder microphone output|
Something develops a fault, like a pothole in a road: the bigger the hole, the greater the pounding from car tyres, so the hole gets bigger. Amplifying feedback can destroy things.
|The bigger a pot-hole in a road||The more violent the impact from car tyres|
Something emerges, like a new interest or fascination, so you study it, build up your knowledge about it, and you might even turn it into a career. Amplifying feedback can create new things.
|A growing fascination with a subject||Growing knowledge about the subject|
Amplifying feedback can start with a change so small that you cannot notice it. A repeating sequence of events can amplify this small initial change. Amplifying feedback is happening when:
- a change,
- leads to more of that change,
- which leads to more of that change …
While amplifying feedback loops tend to change systems, negative feedback tends to prevent 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
Updated: 18 September 2021