You make the difference.

You want to serve humanity? Do the laundry for your wife your kids your relatives and friends who could use your help in times of need. Be aware and awake at all times to the needs of others help to make it easy for them to live their lives day to day...as the Beatles sang in one of their songs..."I get by with a little help from my friends." Giving does not have to be a major donation or grant for a foundation, simply giving a little time to listen to someone or give a lift or a ride, give and advice or a few good words of Love and Compassion to those who could use some; this is giving. It is not something out of the ordinary that needs to be announced or celebrated as there is no giver and none receiving in essence. You are serving humanity the very moment you let your actions become a source of help to ease the burden of others no matter how small or insignificant it may seem.

There is not a leaf that falls from the tree in the forest that does not stir the air that envelops the planet; not an action that is done by you positive or negative that goes unnoticed. You are the Universe in action, manifesting as you go along creating and destroying as the case may be and being a Universe of your own at the same time from within you manifest what is without. It is said careful what you wish for in this life, is a statement that has a far reaching effect that most of us are totally unaware of as what we wish for is and will be manifest in one form or another in time with or without your knowledge of it happening. There times you wonder hwy things happen to you for no apparent reason but you fail to remember that at some point in your life you have set in motion the circumstances that has led to this effect; some call it dejavu when things happen like they had experienced it before. You leave your print in the Universe as so does billions before and after you and as such it all gets molded up into one lump of a Universe of thoughts and ideas , wish and dreams, seen and unseen.
So if you think you make no significant impact upon humanity and the environment while you are alive on this plane of existence, well sit and contemplate deeply on who you truly are and what force you play upon this plane. Those who have made great impacts upon humanity were men and women who saw themselves as prime movers and shakers and not just as a heard of cattle being primed for the slaughterhouse. 

“Do not share the knowledge with which you have been blessed with everyone in general, as you do with some people in particular; and know that there are some men in whom Allah, may He he glorified, has placed hidden secrets, which they are forbidden to reveal.” 
― Ali