Depends you could go into many " fields" get it : ) - you could bein agricultural engineering designing /genectical superior crops,for without food no on lives, or hydrology for without fesh water cattle and crops die and eventually people......maybe a engineer designing new more powerful solar cells to supply power to keep food,water,people cool in turn saving millions of lives in the hot arid lands of pakistan.the "fields" : ) are wide open for engineers of all kinds. My friend engineers conveyor systems for the auto industry.