IB subjects to take for environmental sciences?

Hello! I was recently accepted into IB, but since submitting my application I've had a huge change of heart in the career I was initially interested in pursuing, so now I'm struggling to concretely decide the subjects I should take for next school year. I've been trying to find resources online by just searching "top universities for environmental sciences" and seeing their subject requirements but they're giving me a lot of different answers, and I'm not sure how these courses differ from other schools. Usually the university websites and google ai overview say I should take either bio, chem, or physics, but that's already all the sciences my school offers for IB. I already know I should take a double science, though my school only allows me to take 2 sciences as an HL and SL. My main concerns are the following:

1. Which sciences should I take, and which should be my HL and SL?

2. Would the workload be excessive if my other HLs included Math AA and Psych? (my extracurriculars are also debate and writing in my school newspaper)

3. Should I be considering a specific field of study under environmental sciences to research about right now or should I wait until I learn more in school?

Any and all advice is appreciated, thank you!