It´s hard for me to say as I have only studied Marine Biology and not Environmental Studies, however, I would say like most science degrees they are heavy in mathematics at the beginning and it tends to get lighter as you finish the degree. That being said, statistics is a huge part of biology, especially once you start to look into conservation. My best guess is that maybe environmental studies has a bit more math involved but at this stage, you learn how to use programs and tools to calculate statistics and simulations which is nothing compared to doing calculus by hand.
The short answer is that you cannot EVER escape math. It is part of life and you will have to deal with it, no matter what degree or trade you get into. That being said, biology is nothing compared to chemistry or physics.
I hope that helps!