A study from the University of Southern Queensland published a study in which they found that beards block 90 to 95% of UV rays. Beards slow down the aging process and reduce the risk of skin cancer.
Not just that, they found that beards also reduce the number of pollens and dust that cause asthma attacks. Beards also protect your face from the wind, keeping you looking young.
Other studies have also shown that women are more attracted to men with beards than without. Although those claims might not be 100% scientifically proven, it seems like there's a pretty good case for all you guys out there to grow out that facial hair.