This is one of those ringing phrases that falls firmly into the "Calling A Spade An Agricultural Implement" category.
As such, it's very useful for stating the bleeding obvious in an imposing sort of way, such as "pupils work best in a positive learning environment", or "St Jude's primary aims to provide a positive learning environment".
Ministers can promise to deliver it, and their opposite numbers can deplore its lack. The Department for Education and Skills can produce sheaves of documents on how it should be expedited (now there's a word for another day).
It is also conveniently vague, as it can mean virtually anything. A splendid new college with state-of-the-art everything, including teachers and, hopefully, students, would count; so would a new coat of paint to cover up the grafitti in 4B. But when you try to pin down what the phrase actually means, it disappears up its own excess syllables.
"A decent place to have lessons in" is presumably not quite what our putative minister has in mind, although many a teacher would settle for somewhere where the roof doesn't leak, the plaster isn't cracked, and the students aren't trying to kill each other. But push it further and it becomes so self-evident as to border on tautology. For a learning environment is not what a school, say, is meant to provide; it's what a school is.
That just leaves us with "positive", which surely goes without saying. So a school saying that it aims to provide a positive learning environment is like a bus driver saying he's going to drive a bus, and he's going to try really hard not to crash.