That call for collectivism has the nasty tendency to end up resembling that violent authoritarian society you assume will arise on 'a planet where not all can be fed and not all can live on' without there actually being a real food/energy/living space shortage. Read some real history for numerous examples of such.

If you want to change the world begin with yourself and others may follow. Climbing atop a crate and calling for revolution hardly ever works, if you're lucky the people will ignore you but if they join in the revolutionary leaders nearly always end up like a caricature of whatever their revolution was supposed to bring:

- the French revolution was supposed to give liberty, equality and fraternity but ended up dealing out terror and death

- the Russian revolution was supposed to free the workers and peasants from the yoke of the Czars but ended up putting them under the far heavier yoke of the Party

- the Chinese revolution followed the Russian one and succeeded in killing even more people during 'the Great Leap Forward' (30 to 50 million deaths) and 'the Cultural Revolution' (3 to 5 million deaths)

- the North-Korean revolution was not a revolution but an example of a puppet regime installed by the Soviet Union which ended up outliving its master while outdoing it in destruction and misery

- the Cambodian revolution followed the Chinese one and - on a percentage scale - outdid even Mao in killing the population

- the Cuban revolution was supposed to free the population from its puppet regime but ended up installing a worse and far longer-lasting one

- the Venezuelan revolution was supposed to share the massive gains of the country's oil resources more fairly over the population but succeeded in installing yet another personality cult leader who wrecked (an official term, 'wreckers' were supposed to be anti-revolutionary activists intent on destroying the Soviet economy) the country's economy and infrastructure and main source of income - those same oil resources

This list can be extended ad nauseam since history is littered with failed attempts at collectivisation. Some of those attempts were abandoned when it became clear that the solution was worse than the problems it was supposed to cure, e.g. in Israel, India and the (to a lesser extent) post-WWII United Kingdom and post-Mao China (for now).

Instead of preaching collectivism may I suggest adopting some measures to curb your own energy dependence and sharing this with the world? You will not be able to coax the 'elite' out of their private jets not matter whether they're the 'elite' of a market economy calling for 'green' policies after taking those private jets to Davos or the leaders of a collectivist society (see the above list for some examples) who'll just send the Cheka/NKVD/VoPo to whip you away on some drummed-up charge.

In short, if you want change, change yourself. Stop buying 'stuff', find something else to satisfy those craves which does not depend on those things you think are set to ruin the future. Stop flying, ditch your car, whatever it takes. This will necessitate radical changes in your life style but since (to use your own words) we're at war that should not be a problem. Share your successes with the world, change it from the bottom up. Starting with the people around you convince them of the necessity of this change. They won't like what you have to say but if you manage to convince them you'll have created more change agents who do not need a repressive state to force them to change their ways.