all my thoughts boil the answer down around three problem areas:
1. violence -- the willingness to hurt (or even kill) other humans and animals, up to and including poisoning the planet
2. greed -- the desire for "more", no matter how much you have
3. competitiveness -- the desire to have "more" than others, even when that means you might have less than otherwise
these three are interconnected, of course, and i don't know if it would even be possible to separate them into a single "root cause", nor would i think that would be wise anyway, because they'll undoubtedly need to be treated as a _whole._
as for how to do that, i do have some ideas, but i'm not sure that "some ideas" will be enough. so my main suggestion is to _increase_human_creativity_, because that's the only way that we will ever solve the overall problem, in my humble opinion.
and yes, in many ways, our creativity is the thing that got us into this pickle in the first place. but i just can't think of anything else with even the faintest chance of getting us out.
i might add that time is running short.
most large mammals will be extinct in 10-20 years.
and you know that us humans are "a large mammal", right?
-bowerbird