To produce the same amount of food will require more total resources, including land area, energy, and environmental damage. Your small-scale organic farm-produced product is a luxury good, with luxury inputs.

How is your factory farmed tomato that depends on buried costs of fossil fuel, and inorganic fertilizers, and unsustainable resources not a luxury good? The luxury is the cheap price, which is not sustainable.

Truly organic local food has been produced sustainably for millennia, so to call that a luxury while wallowing in cheap oil subsidized corn food is totally backwards.

Greenhouses produce energy, with solar panels on their roof, even when amortizing all production costs. Inorganic fertilizers are much more efficient than other methods; greenhouses need no pesticides because the environment can be controlled, and use friendly insects that eat the few bad ones there are. Did you even read the article?

who is arguing against greenhouses? the article sets up a false dichotomy between local organic produce, which is more efficient by any measure that includes the cost of doing business, and greenhouses, which are not at all incompatible.