Nouns and adjectives are often combined to create a longer string of premodifiers of a headword. Although this means that a lot of information is packed into a few words, it means that the reader has to do some work to understand the relations between the premodifiers and the head word. Do all the modifiersSee the glossary definition directly modify the headword? Or does one of the modifiers modify a modifier?
Let's take the example catastrophic global warming. In this case we have a headword, the noun "warming", modified by two adjectives - catastrophic and global. The word global obviously modifies the noun "warming". But what about catastrophic? It's not just warming in general which is the topic but global warming. So catastrophic modifies the whole noun phrase global warming.
catastrophic Adjective modifying [global warming] [global warming]Noun phrase (headword: warming; adjective: global)
adjective; noun; [ ... ] = noun phrase
Here is another example. This time with all noun modifiers carbon conveyor belt model. In this case we have a headword, the noun "model", modified by three nouns - carbon, conveyor and belt. The meaning of this is that there is a model in the form of a conveyor belt which carries carbon, so the structure is as follows:
[carbonNoun modifier of the phrase "conveyor belts" [conveyor beltsNoun phrase (headword: belts; noun modifier: conveyor)]] modelHeadword of the whole phrase
We can also have a mixture of adjective and noun modifiers as in the following example:
[tectonicAdjective modifying "plate" plateHeadword of the noun phrase "tectonic plate"] movementHeadword
It's the whole tectonic plate which moves. It's not just tectonic movement or plate movement. Tectonic describes the plate. The phrase could be rewritten with a post-modifying prepositional phrase: movement of the tectonic plate.
You can see from these examples that there is no syntactical method of sorting out the relations between these words - you have to work it out for yourself from the sense and the context. So although these phrases are very dense with information they can be tricky to unpack and occasionally there may be unresolvable ambiguities.
You can see from the animation below that some texts can contain quite a high percentage of noun phrases. In fact this text has even more nouns than the ones highlighted as we have only highlighted those which have premodification.
These examples were sourced from articles in The Conversation: PlateTectonics; Ultra-Processed Foods.