I think we should produce our food locally. If there were a crises in our current situation, there could be lots of starvation in the cities, as it would be hard to bring food in due to traffic concerns. I think we should restructure our cities, among other things. I think sushil had an interesting point in that a lot of our concerns have to do with things that are unnecessary, and as is proven, do not make us happier.
Another big problem, that has to do with our direct effects on the world, is global warming. There are two antarctic shelves; one of them is on land, and one of them in the water. If the one on land went into the water, it would raise ocean levels 20-60 feet, and this would decimate a lot of the population that lives near the coast. One way to cool down the earth would be to put reflectors in the sky. This is doable. Also, the first species of life has become extinct, not due to our actions but due to global warming. This species was a snail.
Our ages are not relevant to this, and frankly I found your response hostile. If your next post is in a similar tone, I won't reply.