How is money a problem? What system would you suggest other than a monetary one? The only alternatives would be an ineffective bartering system and a hated communist/socialist system.
The worlds biggest problem, to me, is the people...not the human race per-say...I mean their attitude towards things...humans murder, humans r racist and hateful, humans r stereotypical, humans think they're the best..etc but...humans also r polite, caring, helpful, considerate, loving...etc Not all humans r murders or hateful or things like that no....humans destroy other living things by bullying or killing...doesn't matter...everyone has bullied someone or something in their life...if they say they haven't..they r lying...most people learn from their mistakes and correct them..or at least make it better...but others; they don't learn and change..they learn, but stick to their negative outlooks... so I say human attitudes is the worlds biggest problem
We can't really tell what the biggest problem of the world is, the human mind is to simple to understand or even agree on what the worlds biggest problem is And I myself am no exception to this