Growing Spaghetti at Spaghetti Junction?

Slow Food Birmingham have submitted plans to create an urban farm on top of Vyse Street multistorey carpark (https://www.theguardian.com/environment/2023/mar/13/from-grey-to-green-unique-farm-on-top-of-car-park-proposed-for-birmingham). The council-submitted plans, include greenhouses, a community space and garden, along with an educational hub and cafe. The intention is to encourage environmental awareness, by providing locally-grown food throughout the year to the people of Birmingham. Certainly, any produce will have very low 'carbon footprints' compared to items in supermarkets. This sounds like an interesting concept that could (slightly) reduce 'greenhouse gas' emissions. The amount of food generated will, however, be relatively miniscule for a city the size of Birmingham. The cost of providing power to the greenhouses in the winter months, could also be problematic. Vehicle-generated air pollution might also be an issue. To prove really beneficial, such developments need to be very extensive and coordinated.