Getting the facts about the need for food security to shape the policy.
In an ideal world, this would be something obvious, but, in the real world, the obvious is all too often ignored.
In the discussion so far, the emphasis seems to be on how may the experts of many an ilk could influence the relevant political decisions with reference to factual information.
Here, one runs into two difficulties; first, it assumes that the decision-makers are willing and able to comprehend the facts, and secondly, that they are likewise willing and able to act in accordance with those facts. It is difficult to see how one may justifiably make such sweeping assumptions.
Perhaps, it is time to try an indirect approach, at least as an adjunct to the inclusive approach one contributor has already suggested. What I propose is to explore the possibility of expanding that inclusiveness.
Here, one may resort to education in its widest sense. Would it be possible to initiate some appropriate public education schemes in order to make the public aware of the need for food security and how it may be achieved within a given geographic area?
If successful, it may induce the public to exert pressure on the decision-makers to undertake actions that would benefit the community.
En passant, may I add that a holistic solution to any given problem can only be achieved through a top-down approach, and this is a logical fact.
Please let me expand on the last sentence of my contribution.
I think most of us would agree that a holistic solution to a problem is the best, because it takes into account all aspects of the problem. These include not only how to resolve it, but also the undesirable consequences implementation of a given solution may entail. For instance, steam locomotion has many advantages over the horse drawn vehicles and sailing, but it also entails a considerable environmental degradation as well as health hazzards. A holistic solution then, would have striven to minimise the latter disadvantages before adopting steam power. Of course, this is too much to expect in the real world, still ...
The possibility of undertaking such an approach depends on one having all the relevant information and the ability to synthesise a reasonable solution to a problem with reference to those facts. Implementation of this solution can then be entrusted to one or more appropriate institutions. This of course, represents a top-down solution to a problem.
In the bottom-up approach, one focuses one's efforts on one aspect of the problem. For instance, the economist may suggest a solution based on economic data, while the environmentalist would follow suit. They follow by necessity, a reductive approach.
As there are more than one possible economic or environmental solution to a problem, and as some of them may be mutually exclusive, it would be extremely difficult to synthesise them into a logically and practically cohesive whole.
And finally, the technical bit. If one wants to find the best possible solution to a problem, one hasto to consider what every possible solution would entail and choose not only what is cheapest, but one having the least undesirable side-effects and what is most appropriate for the community affected by it. So, it is epitemologically impossible to find the optimum solution to a problem using the reductive bottom-up approach.