Related questions which imo do not provide an answer to this one: here, here.
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.
Which basically means that the climate will get warmer in the future, until it will eventually reach some kind of equilibrium.
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.
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.