Kraelyst is the author of the classic Crossings climbing script, still available at elanthipedia.org, which can train from something like 0-400 ranks. At 52 it will work just fine.

I don't know where you're training your character, but if you find yourself in the Theren area there are plenty of trees in Lang and in the blood wolves hunting ground that will train those ranks.

In 3.0, swimming will train the same skill as climbing, so you might consider looking at swimming options as well (if it's close to your climbing ranks)