If you’re really passionate about something, say, an environmental cause, just go for it. Do whatever you can to push it forward, to support it. Realize that you’re not the only one out there thinking “How’s my singular contribution going to make any kind of change?”. There are at least 2 million people in the 7 billioned world who really want to do something but thinking about how they’re not going to make a change in the grand scheme of things stops them. Don’t stop. It doesn’t matter if you’re one person out of 7 billion living on one planet out of 8  in a solar system and in a galaxy out of trillions and trillions. Everything you do makes a change. It’s not the size of the change that matters, it’s the effect that it has, however small, and how it changes the life of even a single person or thing, for even a single moment or day. Just do it. Please. Somebody out there needs your help.