How to discuss in small groups, with your peers, the balanced and practical solutions to the rest of the worlds problems . If they could work towards doing everything peacefully that would be a bonus. It would also bring politics back to life.

We have met the enemy.

Republicans...ban them all to an island and let them do each other in.

Hands down, Lying

Prejudice. Alien attack on all of mankind should solve it.

The biggest problem in the world? Willful stupidity and willful ignorance. There is no known solution.

OVER POPULATION which indirectly causes all the other problems
Depletion of natural resources
Increased habitat loss
Extinction of species
Global warming and climate change
Loss of freshwater
Eutrophication
Deforestation
Malnutrition starving famine
Conflicts and wars.

It exist, let the non-existent flying spaghetti monster sky God take it to non-existance to be with the non-existent flying spaghetti monster sky God in non-existance.

For me I think it's a lack of respect and grace toward others, preventing the feeling of inclusiveness necessary in a pluralistic community. Not sure how to solve it other than just teaching and enshrining the value of understanding others, their roots, beliefs, experiences, why they think or act the way they do.

Easier said than done - I feel myself giving up on people all the time in exasperation, because they are so far gone down a rabbit hole of misinformation or old habits that it's hard to focus on common ground because of the elephant in the room, but if they could meet me halfway, and I do the same, perhaps there would be harmony.

If the solution was easy, it would likely be solved. However, there is value to some to keep the divide going, and that's a whole other story. (Greed, power, control...)

Trying to exist post-truth. There is no solution, just wait for death.

Greed and religion. I don't believe either is fixable. Humanity was a bad accident.

I’m going to assume you mean the biggest problem for humans, and I’d say... evolutionary mismatch.
[en.wikipedia.org]
And I suspect the solution may very well be beyond our reach, but one thing that is clearly needed is a global, unifying narrative to augment, if not replace, the world's competing narratives. It needs to be an unimpeachable story that transcends all local cultures, and can be verified by observation and testing. You know... like science. But not science alone. A reuniting, as John Vervaeke advises, of our Knowledge Traditions with our Wisdom Traditions.

The biggest problem is my lack of money, the preferred solution would be for other people to give me lots of money.

I advocate for relativity.