What careers are available in the environmental conservation field?

I'm really quite ignorant about this, but I was wondering what kind of careers deal with environmental conservation and what they entail. There's probably a bunch of different stuff, but I don't know much about any of it, and I'd really like to. Again, ignorant, but I was thinking maybe something along the lines of stopping global warming, getting animals back from the brink of extinction, helping the ozone, and decreasing pollution in our air and water. I'd especially like to focus on the biology aspect of it if possible. I think that (depending of course what exactly it is) I might like to go into that field, and, soon to be entering high school, I just sort of want some idea on my radar of what I'm eventually going for. How much science, math, technology, etc. do you have to take? Anything else I should know? Thank You so much!!