I'm not familiar with the UNSW environmental science program, but just thought I should let you know that the USyd 'environmental studies' major is more of a rehash from what was left over from the Bachelor of Science (Environmental) after it was discontinued. My understanding is that you'd have another major as your first major and then have the environmental studies as a complement. I'd highly recommend against having simply env. std. as your science major (but if you plan to do marine bio, it goes well together).
I don't know what happened with the discontinuation of the USyd BSc (env), but I'm guessing it was due to low student numbers, and that its units were restricted only to students in the BSc (env) at the time and so were a waste of resources. These units have been opened up now to everyone else in its new form as the environmental studies major. The BSc (env) was also very restrictive in what its students could study and I'd imagine that the BSc (env) at UNSW would be somewhat the same. So I wouldn't take the lack of a dedicated BSc (env) as a bad thing, in fact the flexibility of the stock standard BSc is a good thing.
