I think I got it now. Thanks 
Edit:
… It was all the time in the name and I did not even notice. 
That makes の much clear as well. If english had kanji i would notice it in 5 second xD. I was starting to consider こと having 2 function, but is one and the same function in different situation…
I maybe should pay more attention to nomenclature. Can we have Polish version of BunPro please?
I believe @Asher has it right: it is just a simple omission of the verb. Given that the surrounding sentences use the formal register, if a verb were to be included, it would probably be します.
However, I think that the omission was necessary to convey nuance that wouldn’t be conveyed if the verb were present. I may be wrong, but compared to including the verb, ending it in a VN (verb noun / する noun) without the する gives it the impression that it’s much more directly observable. Not including the verb paints, at least in my mind, a much more tangible experience for the reader, and perhaps even conveys more of a sense that this habit is unchanging.
So while the passage is formal, in cases where using the proper register defeats the ability to convey certain nuance, it is often the author’s feelings and desired impressions to convey that take precedence over formality. (In fact, it can even take precedence over proper tense, as I discovered in an earlier post that prompted me to ask native speakers on HiNative.)
Edit
I apologise anybody wanting to read for the spelling errors and grammar mistakes since it was quite vivid discussion and I have no time to correct it. It all makes sense though so should be not such a problem.
End of edit
I believe we can all agree it is style thing. Nominal sentences are used mostly for that reason in English and even more so in Polish (and Latin if I remember correctly. It was ages ago when I was learning it so it is subject to disbelieve).
But there is no reason to not think about it as jet another legal omission if term “nominal” does not hold much meaning to you (it does to me since is common in 2 language I formally studied: Polish and English). Looking for subject may be tricky but there is not reason to not think it is just “they” as in english “Global warming is getting worse and worse. They are going to destroy the planet!” Who are “they”? Nobody knows, nobody cares. That is not the point of that sentence.
In fact that is how Cure Dolly explains this things. For me it is more understandable to thing about it as normal nominal sentence. Maybe I will be proven wrong late
Btw: I don’t think I am at odds with @Asher here. Different terminology only. Notice his translation is nominal sentence
There are cases where the fact that the noun CAN take する (even if する is not present) has a direct impact on the meaning.
Consider the grammar point N次第. (N is a stand-in for some noun.)
In that case, it usually means “depending on N” (in which case it would have to be followed by で as in N次第で、。。。). However, it can also mean “as soon as,” in which case the N has to be a する noun (and should not be followed by で).
Ignoring the intricacies with the particle で, the meaning is partly conveyed by whether the noun conveys a sense of action on its own. I believe that in Japanese, there are many cases like this, where the noun inherently conveys action just by being a する noun.
EDIT: I’ll include an example from the DoIJG (Dictionary of Intermediate Japanese Grammar) that I think will help drive the point home:
東大を卒業次第、京大の大学院に入学するつもりだ。(Upon graduating from the University of Tokyo, I intend to enter Kyoto University’s graduate school.)
Aside from the fact that で is not present after 次第, one reason why we know that this means “upon graduating/after graduating” as opposed to “depending on whether I graduate” is because the noun, 卒業 can take する. If it could not take する, then N次第 would never convey the “as soon as” meaning.
That a biiig shocker to me actually. Game changer even. I come from (although useful) misunderstanding about how uncommon nominal sentence are, to opinion they are more common in Japanese than in Polish 0_o.
But I will be not able to be part of this disscusion. It going to the terrytory when I am not able to make any “meaningful” gueasses. You will need to give me a “little bit” of time to catch up xD 2N gramma is way beyond my scope.
It is nominal sentence though. So that supports my claim
This is exactly what I had on mind saying “は(like)-sentence”.
So it is exactly as @Asher said: it case of する noun you don’t have to use nominalizers to nominalize the sentence. just drop する. (or even can’t use them I think)
I think we do agree. 
The illusion that we don’t should be attributed to difference in nomenclature we use. I would not think much of it, unless you believe I got something wrong (it happens quite often…). Then please feel free to correct me.
I got where is the confusion, I think! 
As somebody who is not an outsider to English you can be under the impression that this is “verb sentence” because you guys for some reason nominalize verb in the same way you add progressive aspect. But in that case “ing” = こと. It is not a verb. It is a noun created from a verb.
Hope that clears this misunderstanding up
There are a ton of cases in Japanese where instead of a verb, it is a noun. (I wrote the previous sentence in a Japanese way; it is not natural in English. If I were to rewrite it to make it natural in English, it would have a verb at the end, like this: “…where instead of a verb, a noun is used.”)
If this is what you mean by nominalization, then sure. But I just wanted to be specific that the OP’s specific example seems to be one where a verb would be permissible, but they chose to omit it to convey certain nuance.
I am just not fully on board with calling it nominalization because it implies turning something that isn’t a noun into a noun. This is a case where it’s simply a noun. But hey, if you understand it as a nominalized sentence by virtue of the fact that they are not including a verb that they could have included, then go right ahead if that understanding helps you.
EDIT: I regret bringing this up. It really doesn’t matter for the purposes of this discussion and is really off topic. The main deal is that there is no verb, there could have been a verb, but the omission is probably to convey certain nuance.
That very definition of that process. I got advantage over you since I can translate that sentence into Polish. In polish there is no way to mistake it for anything else than nominal sentence.
And the question is not if it is natural in English. But if it is closest representation.
Since we do agree but use different words to say the same I would call it a day
I will only explain what I mean by “nominal sentence”: it is such a sentence that does not have a verb and therefore it is not possible to assign subject in any meaningful way.
We a few way to create nominal sentences in Polish. Some simple examples:
Czytać - dictionary of “to read”.
Książka - book
“Czytam książkę” - I am reading a book.
“Czytać książkę” - nominal sentence in very general form. something like “to read a book”
“Czytanie ksiząki” - act of reading a book
"czytawszy książkę - during reading a book
Notice that there is no meaningful way to assign subject. Those are forms of verb to read in nominal form. They are all nouns. (except “czytam”. it is singular first person present tense progressive form of that word)
I learned something new!
The OP’s example may be a little more controversial since even though it has no verb, the verb is strongly implied. Also, even if the verb were included, the subject would not be any more or less clear.
But I think a really good example of a nominalized sentence is the example I gave:
Technically, this is an inaccurate translation because I am using “to intend,” which is a verb, but the corresponding word, つもり, is a noun. Translating it properly would result in something like “Upon graduating X, it is the entering into Y intention.” That’s a pretty non-controversial case of a nominal sentence because there is no implied verb in the Japanese sentence.
I believe in Japanese it could be still copula sentence (or something). Since strange thing about Japanese is that they do imply だ. That’s where my confusion was: I was under the impression that it is not possible to not imply it. So technically it is not a nominal sentence in a strict sense.
But on other hand that one of the functions. We in Poland even call something like “sentence replacer” since it is often do just that:
“What do you read?”
“harry potter” meaning “I am reading Harry Potter” is function normal “verb sentence”, but if you take it in different context it will “proper” nominal sentence. Np on a cover of a book.
Edit:
This is often more complicated because of those legal omissions. Main question would be if there is a way to add what was omitted. If not then clearly nothing was omitted in the first place
I am not able to say if that is the case here.
So more of purely grammatical difference most of the time?
I see, I’m just not familiar with the terminology. I never interpreted a copula as a verb, but rather as an equation A=B. Not gonna argue linguistics here lol.
My guess is that the OP’s original sentence is not a copular sentence. The sentence I gave before, however, is, and would be even if だ were omitted.
I have that advantage that Polish grammar is very complex so they have to teach as that stuff. But it is very precise.
English grammar is easy, but messy. Most difficult thing for me was to figure out when you use word as verb, noun, or adjective…
“I am reading” verb
“I do some reading” noun
“reading book” (let’s imagine that you call a book you learn to read from) adjective
Nightmare…
I’ve asked about this on HiNative: https://hinative.com/en-US/questions/18209610
I might not get any responses since I might be asking something a bit too heavy on linguistics.
I would not make native an expert on the language though, but I am interested anyway.
People tend to not understand their language on rational level. We know how to use it, but why it works? We never had to care. It is like driving a car. You don’t think what you do. If you would drive from time you are 1 year old you would not even understand how you do what you do. 
But that will be interesting to have theirs input
Welp, so it turns out that you could indeed add the verb, but, contrary to my expectations, you could also add the copula and be fine.
In each case the nuance changes, though. And I am pretty sure my initial assertion that the reason for the omission was to convey a certain feeling is pretty accurate.
so we do agree
Wow, these kinds of nuance is gonna be pretty difficult to grasp despite being pretty much the most basic forms of grammar you learn right at very beginning.
That is my experience with english, so it may not apply here, but I think there is no point in worrying about it.
Just remember for natives it can imply both things (whatever that things are) and over time drop your English translation from Japanese. Let your brain do the rest of the job itself.
It just happen to be that knowing if “reading” is noun, verb or adjective is useful only at the start of learning. Knowing it does not matter to me anymore. It is always “reading” regardless.
Making such distinctions helps 3 types of people: total beginner, translators, linguists.
I would go with what is easiest to understand to me with my background (nominal interpretation) but it something else click better with you then I don’t see a problem. Soon enough you should drop that interpretation anyway and start to feel the difference.
You guys clearly are not aware that what you are saying is often nominal sentence, not progressive tense. Nor you spend a second thinking if “reading” is a verb.
In fact grammar is just theory. To this day we don’t know for sure if english has future tense or express it by present tense.
“I will read” - future? or statement about my “will” now.
it is fun debate, and very useful one, but better not go crazy with conclusions xD
Edit:
In this video there is little bit about lacking tenses in the language (chinese, japanese, english as examples) go to 6:40 to listen about lack of “future” in English:
hmm… be looking how fast china grows I can kind of agree English has no future xD
Hmm… you have forgotten to ask if they read it as sentence that does neither imply だ・する nor obvious subject. Just plain non verb sentence. It would be interesting to have a look if they would see it that way without being prompted to choose one or another.