Power
Yours is a peaceful, subtle form of power. You can't move heaven and earth. No matter how bad you are at your job, and no matter how ineffective that irrigation system you spent ten years designing proves to be, you won't be able to destroy earth in even a tenth of the ways a nuclear engineer can.
But if you do your job, you may just end up saving a few acres of land from erosion, or bringing water to a part of the world that could really use it. Ah, the power to do some good.