We know the answer to this question, because Cuba showed us how to do it 20 years ago.
Not because they were green back then, but because they had to shift rapidly and nearly totally to self-reliance.
Why? With the collapse of the Soviet Union and a tightened US embargo, oil imports were cut by over 50%, leaving that island on the verge of total collapse.
So, what did they do? I will provide a synopsis below, and you can see for yourself in this documentary, 'How Cuba Survived Peak Oil', which is getting some buzz.
First, from the bottom up, people began reclaiming land, whether it be vacant lots or rooftops, and began growing vegetables on them (via bluehouse diaries).
The government, facing the worst crisis since 1962, gave support to this effort and began emphasizing urban food production.
Food now had to be grown locally because of the high costs of transportation.
This became a net positive, because it fostered better community relationships, and ultimately made healthier communities as veggies became the core of the Cuban diet.
Second, sustainable practices were a necessity, and Cubans re-learned the importance of 'working with nature instead of against it,' as one Cuban says in the film.
Here we see the importance of recovering lost knowledge - only elderly farmers remembered how to train and use oxen, so they were employed to train others.
Monoculture was abandoned in favor of biodiversity.
Third, land use and ownership was a key element. Large state collective farms, a legacy from the Khrushchev era, were broken up and given to smaller farmers and co-ops, on the condition that they be used to grow food for the nation.
Workers' collectives run large urban farms, produce markets and restaurants. Hand tools and human labor replace oil-driven machinery. Worm cultivation and composting create productive soil. Drip irrigation conserves water, and the diverse, multi-hued produce provides the community with a rainbow of healthy foods.
In other Havana neighborhoods, lacking enough land for such large projects, residents have installed raised garden beds on parking lots and planted vegetable gardens on their patios and rooftops.
Says Montereyan on Bluehouse:
"One of the strongest aspects of the film is how well it shows the centrality of oil to modern life."
Losing oil means not just problems for auto transport, but massive problems for agriculture.
Our food is almost totally dependent on oil and natural gas - to power tractors, for fertilizer, to bring food to market.
Most of Cuba's electricity was generated from hydrocarbons, and with widespread blackouts, not only did the economy suffer, but so did food. Without refrigeration, food must be eaten soon after it is harvested or else it would spoil.
There's a clue or two.