It’s the standard bio series (BIS2ABC). I only needed two quarters of chem for my track (Ecology/Conservation/Biodiv), while other tracks and similar majors need 3. You can do the physics 7 series or the physics 1 series – I did 7 and it sucks but I got an A. I’ll mention that you can take the math 17 series, which is “math for biosci,” and is definitely easier than the 21 series, which is the “engineering math” series.
So the prereqs have some variety, but in general they’re the same as other majors. This is good because it lets you swap majors fairly easily. The bio/chem/physics majors only start to get serious with their upperdivs. In my opinion, lower-div bio, chem, and physics are so universal that you won’t be at the bottom of the pack just because you’re “less sciency” as an envirosci major than others. And I mean, in BIS2A everyone’s a freshman – a bio major might be more enthusiastic about the material, but they don’t know any more about it than you do. Also, only BIS2A is microbiology cell-type stuff, BIS2B is about ecology and BIS2C is about evolution so I REALLY enjoyed those.
Overall, I think the ESM major was a good choice for me, mainly because it is very versatile in what classes you can take (a lot of options) and in what careers you can go into. So I can say that I have experience in field ecology, lab work, biology, policy, economics, GIS mapping, etc. Very diverse. I feel like the EPAP major is more narrow in that it strongly focuses on policy.
The main drawback of the ESM major is that I wish there were more science-based classes and fewer policy-based classes. (I really don’t like policy.) The Ecology & Evolution major is one I strongly considered, but I decided to go with ESM just to get that wide range of options after graduation. ESM kind of leaves both the sciences and the humanities open to you. To alleviate this, I took on my Geology minor, which gave me the science I was looking for :D. I also took the CA Ecology & Conservation field studies course, which was 19 units (!!!) and super awesome.
Overall, good major, good variety of classes, good outlook after graduation. ESM vs EPAP depends on how much you enjoy policy and law. If you’re super-science focused and are positive you want to become a researcher or something, maybe try a major with less policy/econ. The end 