I am being a bit selfish - but I think that applies even to philanthropists. They do it because it makes them feel good, or to atone for past sins, or to make future generations look upon them as "good".

But I also disagree that my individual effort will have even the smallest effect. I'm one of nine billion. We frequently underestimate how big a number that is, and how insignificant the individual is when looked at as part of the whole.

You could count people at a rate of 10 a second, and still take 70 years of non-stop counting to count everyone in the world.