Hmm - I think you may have slightly misunderstood OtH's post! In my day it was three years at University, a year at Law School, then a two year Training Contract; and it has changed a bit since then, but not dropped by 85%.
It's a job I did for my last 30 years and not one I would recommend to you now. The work is being progressively de-skilled and you spend more and more time competing with sheds who replace a legal process with some very expensive software and a high turnover of unskilled operators.
'Fraid so.

More seriously, a lot of public sector staff shaken out in the last four or five years have found it very difficult to get work in the private sector because the jobs that they have been doing either don't exist in the private sector or are much less valued and therefore much worse paid. I would be surprised if you could find anything which used your present skills on the sort of salary you are now getting, but that's not the only factor. To set up my own firm was exciting and fulfilling, even though I would probably have earned a lot more if I had stayed in local government
FWIW I would sit down and do an honest analysis of what you like about your present job and what you don't, what you are good at and what you aren't, what unused skills and experience you have etc etc. If your family and financial commitments allow it, a complete change based on your Environmental Sciences degree could be very invigorating.