I use a greenhouse to make a special hot environment for sensitive plants. Why don't we use then to make a controlled environment to grow food crops in geographical areas outside thier normal range or at unnatural times of the year?
For example: strawberries may be gown out of season in heated and lit greenhouses, citrus fruits may be grown in northern Europe outside their range and weat may be grown in the winter and further north than normal.
The greenhouses may be made disease and pest free by careful airlocks and control of input and have artificial water, air and light supply, and the minerals needed could be carefully controlled. The use of artificial soil would make the control of the plant assemblage inside easier with monocultures being usual.
A version of sealed unit could be used to house disease and parasite free farm animals which could be fed from the plants in the greenhouse. (this is an extension of factory farming) . The animals would need to be specially bred and selected to thrive in this environment.
I would include mink farms and other farms for growing skins and feathers for human adornment. By using specially bred animals their instincts would fit their restricted environment and we would not be cruel. We have done this since the beginning of humankind. We should not treat human beings like this.
England could be mage self-sufficient in its supply of exotic fruit as well as maintaining food production throughout the year.
Nuclear power plants could supply power for heating and lighting. Greenhouses in arid regions would make the control of water supply obtained from the air possible.
Thus Israel and Palestine and other arid lands could grow crops that require more water than they can normally supply by using a greenhouse to conserve water. Crops such as rice could be grown there.
Chris.