How can I access a journal's bibliography format and use it myself?

There is no single answer; this really depends on the journal.

Some journals that accept LaTeX submissions have detailed author guidelines outlining how you should generate your references. Some even come with a LaTeX template that includes a BibTeX (.bst) file for you to use. If the submission guidelines mention anything explicitly, obviously that's what you should be using.

Depending on the publishing workflow, submission of .tex instead of PDF files might be more of a courtesy to authors, because the real publication process may not involve LaTeX at all or only in preliminary stages. In this case, the references will probably be extracted properly regardless of the exact formatting you apply when you submit your article as long as it is consistent and the information complete.

For publishers that postprocess submitted .tex source it may be a problem if you do "non-standard" things in your document. Unless there are specific guidelines to the contrary it is probably better to stay on the safe side by not using fancy packages or doing fancy stuff. For bibliographies it is worth keeping in mind that biblatex requires a completely different workflow than classical BibTeX. That's why I would usually not use biblatex for journal submissions, even if there is no explicit information about the bibliography workflow. See also Biblatex: submitting to a journal. But if the publisher never gets to see the .tex source and only ever works with a submitted PDF that is less of an issue.

As David Carlisle mentions in the comments the author guidelines for Global Environmental Change say

References

There are no strict requirements on reference formatting at submission. References can be in any style or format as long as the style is consistent. Where applicable, author(s) name(s), journal title/book title, chapter title/article title, year of publication, volume number/book chapter and the article number or pagination must be present. Use of DOI is highly encouraged. The reference style used by the journal will be applied to the accepted article by Elsevier at the proof stage. Note that missing data will be highlighted at proof stage for the author to correct.

So you need not worry at all about the exact formatting of your references as long as the output is complete and consistent (the latter of which is one of the main points of using bibliography styles in the LaTeX world, so you should be good as long as your input – i.e. your .bib file – is good).

Later on we find

Submission

Our online submission system guides you stepwise through the process of entering your article details and uploading your files. The system converts your article files to a single PDF file used in the peer-review process. Editable files (e.g., Word, LaTeX) are required to typeset your article for final publication.

which suggests the publisher may want to process the .tex source directly, so I would advise using only "standard methods" to generate the bibliography. I'd definitely not go for biblatex here, but I may be tempted to use a BibTeX style that is slightly more modern than plain (which was written before DOIs were a thing) – maybe something from natbib.

Elsevier has several publisher classes (https://www.ctan.org/pkg/elsarticle and https://www.ctan.org/pkg/els-cas-templates) also including bibliography styles, that you could check out. Though a simple documentclass{article} will probably do the job just as well.

If in doubt, don't listen to random people on the internet: Get in touch with the journal editors and ask them.