Using greenhouses to prevent famine is a nice idea in theory, but in practise the world has had many famines since the introduction of greenhouses. Realistical

Using greenhouses to prevent famine is a nice idea in theory, but in practise the world has had many famines since the introduction of greenhouses. Realistically, it's a problem with food distribution whereby the richest countries can attempt to purchase food from alternate supplies and the poorest countries simply starve.