So how does one ever stand a chance of saving the world before WWlll breaks out? What can anyone do to stop a nuclear war between US and Russia? Really I've never had much hope for the future. Human history since the start of agriculture has been about money, politics, and power. "Go and kill the barbarians over there so we can steal their resources." It does sum up much of the last ten thousand years. Maybe no one can ever save the world and civilization is doomed for collapse. It happened to Rome, Egypt, the Maya, and Mesopotamia. The financial troubles in western world are only the first sign of whats to come. Then theres the impending ecological collapse caused by outdated industrial farming and the use of nature as a dumping ground. All seems even more hopeless as younger generations buy into the techno-obsession pushed by a technologically-dependent world.
To answer the original question; how can one save the world? Perhaps no one or nothing can save it. The clock has struck the last hour until we know its a days of final resolutions. Then perhaps this world of resolutions has meant a type of rescue (if its not too late) from that most unacknowledged. Below I outline briefly a few ways to "save the world" though that could be a wrong term for it all.
1. Permaculture.
Why not replace anthropocentric farming with natural way of farming? Blend food production right with nonhuman-made nature by amplifying food forests and growing patterns found in those same forests. It might bring people back down to Earth as they relearn the connection to a holistic nature severed by a technocratic control. Besides humans can't leave wilderness alone anyways so we must well do something with it. The best use would be integrated food landscapes. And then maybe feed the world in the process.
2. Allow true democratic decision-making.
Get rid of psychopathic-control freak-political ignoramuse-patriachial-ideological fundamentalist of all stripes. Do we really need to spend money bombing another country on an alleged danger to us? Do we really need more synthetic chemicals in the environment? Who should be allowed to steer the control of new technologies, industry or the people affected?
Not that I believe the above will ever by a reality. It seems a part of human nature to kill eachother for money, oil, and control. Perhaps Monsanto can engineer oil suitable for human consumption. I'm being sarcastic.