We know that the Earth's innards are stratified based on temperature and composition. Two strata which interest us especially are the mantle and the outer core. So, as you can see, the Earth's magnetic field is nothing to scoff at. It affects us much more than the average Joe Smoe would even care to guess. From keeping two imaginary, magnetic bodies stuck fast to one another through thick and thin to providing us with palaeomagnetic fossils and protecting us from intergalactic charged particles, this wonder of nature is exactly that.
Magnetism is a benefactor among phenomenon.
The Earth's magnetic field, a prime example of magnetism at work, is formed by the complex swirling and convection in the bowels of the Earth. It radiates from the planet to protect us from all sorts of galactic bad stuff. We humans have been learning to harness and discribe its motions and power. Who knows what good deeds the future holds for our magnetic field. American icon, rumoured to be immortal.