# Is climate change a vicious circle?

My question refers to the current process of climate change. CO2 is rising, which leads to the greenhouse effect, which raises temperatures. This leads to more wildfires, which reduces number of trees, increasing CO2 and reducing CO2 capacity absorption. Ice caps start to melt, which reduces sunlight reflection (less snow), trapping more heat on atmosphere. Water rises, taking over land and trees, further enhancing the CO2 absorption capacity. Oceans acidify, lowering their CO2 absorption capacity too. Etc etc.

It seems the process of climate change is a "vicious circle", with a lot of feedback loops reinforcing the trends.

Is this the case? Are there counteracting forces that go against this circle?

Related questions which imo do not provide an answer to this one: here, here.

• +1 : I've done a general answer, but a more detailed one going into some of the feedbacks would be great! – Semidiurnal Simon Jan 14 at 10:57
• Not enough for an answer, but: Some of the positive feedback loops have a "tipping point", a threshold beyond which the effect becomes a "runaway" effect. Examples include the abrupt change of albedo when the sea ice has melted all the way so that the dark water is exposed, leading to higher water temperatures and consequently more ice melting, or the thawing permafrost releasing large amounts of methane leading to more thawing. – Peter - Reinstate Monica Jan 16 at 2:31

There are indeed a lot of positive feedback mechanisms, i.e. a warm climate leads to a warmer climate. From this Wikipedia article, they are:

• Carbon cycle feedbacks
• Cloud feedback
• Gas release
• Ice-albedo feedback
• Water vapor feedback

However, there are also a few negative feedbacks (same source):

• Carbon cycle
• Lapse rate
• Impacts on humans

Now the question is: what is the net budget between positive and negative feedbacks? To assess this, climatologists use some metrics, the main ones being "transient climate response" (TCR) and "equilibrium climate sensitivity" (ECS). From Knutti et al. (2017):

TCR is defined as the global mean surface warming at the time of doubling of CO$$_2$$ in an idealized 1% yr$$^{−1}$$ CO$$_2$$ increase experiment, but is more generally quantifying warming in response to a changing forcing prior to the deep ocean being in equilibrium with the forcing. Based on state-of-the-art climate models, and instrumentally recorded warming in response to CO$$_2$$ and other anthropogenic and natural forcings, the Intergovernmental Panel on Climate Change's Fifth Assessment Report (IPCC AR5) assessed that the transient climate response is 'likely' (>66% probability) to be in the range of 1 °C to 2.5 °C.

By contrast, the equilibrium climate sensitivity (ECS) is defined as the warming response to doubling CO$$_2$$ in the atmosphere relative to pre-industrial climate, after the climate reached its new equilibrium, taking into account changes in water vapour, lapse rate, clouds and surface albedo. [...] The estimated range of ECS has not changed much despite massive research efforts. The IPCC assessed that it is 'likely' to be in the range of 1.5 °C to 4.5 °C.

Which basically means that the climate will get warmer in the future, until it will eventually reach some kind of equilibrium.

• The blackbody radiation seems to me to be a very strong limit preventing a vicious circle from continuing. T^4 is a very strong feedback indeed, and I am glad of it! ;o) – Dikran Marsupial Jan 15 at 9:16
• @DikranMarsupial The T in T^4 is the average world temperature, in Kelvin. If the temperature rose so much that this effect would prevent any further warming, we'd already be in a hothouse; we must hope for all effects to stop global warming before the planet becomes uninhabitable for vertebrates in general due to inadequate cooling. – toolforger Jan 15 at 9:30
• @DikranMarsupial To follow up on toolforgers comment: a whopping 10 degrees rise in average temperature from 10C to 20C would only result in an (293/283)**4 = 1.15 increase in blackbody radiation. – Jan Doggen Jan 15 at 15:05
• Yes, but that is quite a lot. Surface radiation is about 400Wm^2 but CO2 radiative forcing is only about 1.5 Wm^2, so a change of 1.15 in radiated energy would be a difference of 60 Wm^2. It could be that I have missed something (I am not an expert), but as I understood it, the reason CO2 has a substantial effect is that it makes small modulation of a vast energy flux. SB is a change in the vast flux. – Dikran Marsupial Jan 16 at 8:07
• @DikranMarsupial How about "before our highly-integrated global economy breaks down"? That is almost as scary, if you ask me. – Oscar Bravo Jan 16 at 15:01

You've correctly identified a number of individual mechanisms which form "vicious circles". They're more formally known as "positive feedbacks". As you've noted, loss of albedo (reflectivity) from melted ice is one. Some of the others you've listed are a bit more complex - e.g. trees will regrow, algae in oceans are quite effective at removing CO2, etc.

One of the big concerns that people have is that if some of the larger positive feedback mechanisms get going - e.g. the melting of frozen methane on the seafloor - then it will impossible for anything that mankind does to stop it, and even if we completely stop emitting greenhouse gases we'll get pushed to a much warmer climate.

There are also negative feedback mechanisms. For example, a warmer atmosphere is likely to have more clouds, which will reflect more sunlight. But the warmer atmosphere can also hold more water vapour, which itself is a greenhouse gas, which is a positive feedback.

One of the reasons that climate science is hard is that all of these positive and negative feedbacks interact, making the earth system a very complex one.

• Hi. +1. A few tips for other positive feedbacks, but they'd need some research: forest retreat (drought, fire, agriculture) release greenhouse gases and reduces biodiversity, the opening areas turn into steppes. Melting ice exposes dark surfaces for warming which leads to more melting. Warming and acidifictaion deoxygenizes the ocean which looses abilities to act as a carbon sink. CO2 warms the atmopshere, which then contains more water vapour, which warms the atmopshere. – user18607 Jan 14 at 11:04
• Yes, sorry, i didn't mean to correct you, just offer some fuel :-) – user18607 Jan 14 at 14:04
• @ebv fair enough! I'm not going to edit into here, because there's a good, and more comprehensive answer, already. But thanks :) – Semidiurnal Simon Jan 14 at 16:04
• Climate science isn't hard! Don't be ridiculous. These complex mechanisms and cross-interacting factors? Nonsense. All you really need is a little bar chart with some cherry-picked temperature data from the last hundred years or so, share it on Facebook, and presto! You're an expert. Duh. – Lightness Races in Orbit Jan 16 at 13:12
• Ad melting of frozen methane - it's not that humans couldn't do anything to stop the planet from warming, it's just the point where reducing the carbon dioxide production isn't going to be enough (i.e. even if we cut all carbon dioxide emissions, the methane will produce as much or more as we used to). We can still do things like add particulates or sulphur dioxides to the atmosphere, produce radiators that reflect most light but have high emission in the right IR range etc. The difference is we're no longer in the "let's go back mode", but exploring new climate territory :) – Luaan Jan 17 at 9:23

Climate Change definitely seem like a vicious cycle on a decadal scale. As other answers have pointed out there are numerous positive feedbacks such as:

1. Warmer atmosphere holding more water vapor (which is a GHG) leading to more clouds
2. Reduced snow cover reflecting less solar radiation (lower albedo)
3. Reduced snow and ice cover on land leading to faster release of previously "locked up" methane in permafrost
4. Warming increases decomposition of organic matter in general ( particularly worrying in previously waterlogged area e.g. peatland)

However, this "vicious cycle" will likely decrease in strength over time, for reasons like blackbody radiation mentioned in the other answer. "Potential" full or partial reversal of the cycle, however, is dependant on biospheric feedbacks (blackbody radiation can only stabilize). Simply put, organisms collectively tend to stabilize environmental variables within certain ranges for homeostasis sake (humans are outliers, unfortunately), especially for bioresources like carbon dioxide and methane. I argue from an evolutionary standpoint, that most biospheric negative feedbacks (which is in essence ecological responses refined through eons of large-scale nutrient imbalance selection experiment) operate on a larger timescale than the aforementioned positive feedbacks because throughout Earth's history, it is unlikely that the Earth has experienced the current fast rate of warming that results in effective selection dynamics (you may argue we had seen that but massive and scarce pulse disaster is an example of ineffective selection that doesn't lead to meaningful adaptation and act more like lottery, whereas continuous and gradual impact is the best form of selection pressure). If there exists a biospheric "negative feedback" mechanism that leads to very fast cooling, in itself it would not be sustainable (just like fast warming) and would be weed out by evolution.

So enough of evolutionary theory, how does an ecological negative feedback work (approximately)?

Carbon dioxide fertilization and warming would favor and select the most efficient primary producers within the community repository (those who can use CO2 for growth and reproduction efficiently would be able to expand in numbers). Globally, in ocean, it would be r-strategists (phytoplanktons) that can grow and reproduce quickly whereas on land it would be trees that have conquered the limitation of height in primary production (I'm talking about in general what would be favored, there would be local variation no doubt). Also, note that two of the fastest flowing nutrient cycles i.e. C and N cycles are to some extent coupled and increased N deposition has indeed been shown to reinforce carbon sequestration (there is solid evidence of the increase in concentration of N compounds in the atmosphere which would deposit back to the environment when rained down.)

It should be noted that while the primary producers have some time to enjoy the "feast", the increased input of organic matter (OM) in the ecosystems (from primary producers) in turns constitute another selection pressure to select the most efficient consumers and decomposers. The duo processes would get closer and closer to an equilibrium eventually, but it is not likely to be the same state we had seen in pre-industrial time.

So yes, in the "short-term" i.e. decades (which in itself is considered "long" relative to human lifespan), climate change does seem like a vicious cycle but on a longer-term it would likely find its "peace" through wax and wanes of biospheric responses.

The wording of the question suggests that it is asking about what climate scientists refer to as a run-away feedback. There are, and always have been, positive feed-backs in the climate system, but these are balanced by the major stabilizing effect of emitted infra-red radiation: the simple fact that the Earth emits more heat to space when it is warmer, and this tends to counter-act and heating effect.

Hence, our climate behaves like a benign, self-stabilizing system, not one that spirals out of control as soon as it is perturbed.

For instance, a 1 degree Celcius warming will increase the amount of water vapor in the atmosphere by about 6-7% (because hotter air can carry more water -- see, for examnple, skeptical science). Water vapor is a greenhouse gas, so this extra water vapor will create extra heating of around 2.2 W m-2 (AGU Report). At the same time, an extra degree of Celcius means that the Earth is radiating more heat to space. This can be estimated from the Stephan-Boltzman law (maths omitted) and it turns out that 1 degree Celcius of warming results in roughly an additional 6 W m-2 being emitted to space. The extra cooling effect (6 W m-2) is greater than the feedback effect (2.2 W m-2) so the net effect is that when the Earth's climate is subjected to a temporary warming it will cool back to its equilibrium.

The reason why we see exponential warming now is not because of a vicious feedback, it is because we are applying an exponentially increasing forcing.

However, there is no absolute physical law which says that the stabilizing effect of emitted infrared radiation always has to win over the feed-backs. There is a concern that rising temperatures might strengthen the feed-backs so much that they overwhelm the stabilizing effects, leading to an unstoppable run-away feedback which could well wipe out all mammals, us included. That would be vicious. It has to be said, of course, that there are no credible predictions of a run-away feedback anytime soon -- the debate there is whether our models would be able to spot one before it happened.

Yes, you are quite right, it does create a vicious circle, though not quite as vicious as some might think. As you suggest, there are natural forces which ameliorate the effects of this vicious circle.

Most of the woodland burned by these fires regenerates, though this takes a while. Where it doesn't regenerate, its place is usually taken by agriculture, which also consumes CO2, but less effectively than trees.

The de-icing of the NW and NE Passages will allow ships to take short cuts to their destinations and thus use less fuel, which lowers CO2 emissions.

The increased CO2 in the atmosphere will allow vegetation, both natural and agricultural, to grow more efficiently by perhaps a few percent. This applies not only in the rainforest, but in the oceans where the majority of photosynthesis takes place (in this context I include all photosynthetic marine organisms, not just vegetation as we normally think of it).

Just as there are more factors which create a vicious circle, so there are more ameliorating factors which lessen it, but not enough to prevent an increase in the vicious circle you speak of in your question.

• Comments are not for extended discussion; this conversation has been moved to chat, minus previously deleted comments. Note that the Code of Conduct still applies in chat: keep it civil. – gerrit Jan 15 at 13:08

It isn't Co2 (sorry I know that's likely unpopular for most to hear), it's (primarily) the sun.

Real quick, rising Co2 doesn't cause wildfires, trees love Co2, visit a greenhouse. Wildfires are a result of (bleep holes) running around lighting fires. Look it up, nearly 200 people arrested so far in Australia for arson.

Ocean rise prediction data (focused on Co2) fails to account for increased plant intake due to plant growth explosion. Similarly, population reduction doesn't account for the 12 gallons of water that makes up an average male. Reduce population by 1 million average men, increase water levels by approx 12 million gallons.

The ice was always supposed to melt, it's a byproduct of a catastrophe.

However, the long answer to your point is technically "classified" by the U.S. military and a secret. It was part of my training in the USAF, couldn't do my job unless they told me. What's classified is less the information but more our comprehension of it. Foreign nations know of it, they just don't have the big picture. Once you know, Climate Change is literally a hoax as it's currently being peddled.

This is one entity that monitors the real source of our "Climate Change" NOAA

This site also has some good info; Earth's Electromagnetic Field

My previous source was NORAD, I'm retired now, can't access it so, NOAA is the closest thing I've found publically available. We referred to it as "Geo-Planetary Index", it was/is monitored by the "minute" because it's that critical to success of the military's mission.

I don't know if politicians know the truth but some manufacturers clearly do. One example; ECC_memory

I'm not a fan of using Wiki however, the author of this excerpt from the above link knows what I know; "research has shown that the majority of one-off soft errors in DRAM chips occur as a result of background radiation, chiefly neutrons from cosmic ray secondaries, which may change the contents of one or more memory cells or interfere with the circuitry used to read or write to them.[3] Hence, the error rates increase rapidly with rising altitude; for example, compared to sea level, the rate of neutron flux is 3.5 times higher at 1.5 km and 300 times higher at 10–12 km (the cruising altitude of commercial airplanes).[4] As a result, systems operating at high altitudes require special provision for reliability."

If the public really wants to have an appreciable effect on the temperature, find a way to make the roadways, solar panels white/reflective. Plant more green things...

Edit/Update: Just keep this in mind, Co2 not being the cause isn't my "opinion". It doesn't matter if you have a PhD in "Climate Studies", it doesn't change reality.

More things to consider:

How many colliders are on the planet? (Hint: 40% are underground/classified i.e. don't exist, why?) What alternative things are they used for beyond scientific study? When do they fire them? Where are they geo located, what's unique about their placement? Why are they often fired simultaneously on opposite sides of the globe? Who controls them?

Answers those questions, you'll realize "they" know it's not Co2, and you'll know it too.

• Are you denying the greenhouse effect of CO2? (just to start with) – luchonacho Jan 17 at 17:45
• @AHBeing I think, you vastly underestimate the neutron flux in the area where you operate your computer. – klanomath Jan 17 at 23:09
• @luchonacho, there is a reason it's called the "Greenhouse" effect. It's used to make plants grow faster, healthier in a shorter period of time. If you've ever spent any time in a greenhouse the first thing that hits you is the feeling that you need to "chew the air" before you breathe it in. That being said, as it pertains to "climate change", G00gle is an "echo chamber", try using a different search engine, shockingly the results are less biased, example; [Ice Core Samples ](21sci-tech.com/2006_articles/IceCoreSprg97.pdf) It's difficult to know the truth when it's suppressed :/ – A.H.Being Jan 18 at 1:57