Deletion of List of environment-theme lists of topics

Comment: the main page and '''merge''' the rest into a more manageable number of pages, if too large for one. Few of these subpages are so large as to warrant separate pages for each letter of the alphabet, and each page unnecessarily duplicates a large opening section. Other than that it serves as a "''structured list to assist with the organisation of articles''", which #LINK explicitly allows. See also 
Stance: keep
Cited policy: Wikipedia:What Wikipedia is not (WP:NOT||WP:LIST)