I am a current college student who is pursuing a degree in environmental economics. I have a year off from college what kind of related jobs would benefit me the most in understanding the field?

Travelling.  Nothing you do domestically will be as valuable as travelling and experiencing economic realities in other nations.  I mean reality in the total sense, rather than the oft-used poverty sense. has excellent suggestions.   For instance, in certain parts of Africa - mobile phone credit is the de facto currency.  That's economics but by physically being present in the location you will be able to better understand why.  The lack of landline infrastructure, the widespread availability of cellular networks, the bespoke micro-payments system established by cellular providers.  If you travelled to South America - particularly Columbia, you would witness the exchange of raw coca for goods and service, despite it's illegality.  Similar for diamonds in Asian countries.  Travelling will allow you to apply what you have learned and forge new understanding.

1. Travel only on foot. 2. Examine Nature close up as well as the overview. 3. Discuss the question of an environmental economics with anyone and everyone. 4. Breathe and open your mind to that which is beyond thought as you know it.