I'd like a career that helps people or the environment in some way

Hello Kennedy!  I'm glad you are exploring your options now and looking at how best to utilize your educational experience to pursue a career that interests you most and will be most fulfilling!  I am an Industrial Engineer...I've always loved to organize, prioritize and logically place things in order to optimize results.  I've worked in a large manufacturing environment and in other settings and one thing I've learned over the years is...engineers can be found in various work environments, various levels of an organization and doing a vast array of work tasks based on the company/organization's particular goals. One cute "snippet" I found might help you some...Civil engineers build the world; Mechanical engineers run the world; Electrical engineers power the world; Computer engineers program the world; Electronics engineers gadgetize the world and Industrial engineers manage the world.  ALL engineering careers are going to contribute to our environment and society but one question that is tougher is what organization/company are you wanting to work for in the future.  The best way to learn (that I've found) is through Work-Study, Internship programs and volunteering for various organizations (I still volunteer today with FIRST Robotics!).  You learn first-hand what a company is all about and how they are tied to our world and what they contribute.  I believe your love for Math and Science is much needed and pursuing an engineering degree is going to offer you that opportunity to work with these particular skills for a lifetime, but ultimately your choice in employer will drive how closely you contribute to society in a manner that you prefer.  I am now a Manager at a gas utility so I don't really do much "engineering" as much as managing people now.  But with the previous positions I've held, I've optimized workloads for assembly line workers, worked with vendors to optimize delivery of materials, re-engineered production lines, managed hardware inventories and deployments, implemented new software solutions to field personnel, lead projects within my organizations and served on special focus groups as a resource and subject matter expert.  The aspect of Industrial Engineering that I've always loved the most and appreciate greatly is this field of study has always been closely tied with "working with people" and the systems that people work with...meaning I've never been locked in a room (or with a tiny group) for any great length of time...I've always been able to work with people and allowed to get up (from a desk) to go look, see and do to provide more viable solutions.  I'm glad you're considering engineering and I'm wishing you only the very best with your college career and your future engineering career.  If I can help further, please let me know.  Remember to never stop learning!!    -Priscilla