How is urban farming a serious problem to solve?
Growing [X] amount of produce locally would provide a much-needed source of cheap produce and/or revenue to the local community. There's also general health benefits of the added greenery consuming excess CO2. Even better, captured rain runoff goes back into the soil sooner rather than becoming further concentrated with toxic chemicals before it reenters the ecosystem.
> Neighborhood Food Outlets, Diet, and Obesity Among California Adults, 2007 and 2009
> Food outlets within walking distance (≤1.0 mile) were not strongly associated with dietary intake, BMI, or probabilities of a BMI of 25.0 or more or a BMI of 30.0 or more.
https://www.cdc.gov/pcd/issues/2013/12_0123.htm
> The Geography of Poverty and Nutrition: Food Deserts and Food Choices Across the United States
> Using a structural demand model, we find that exposing low-income households to the same availability and prices experienced by high-income households reduces nutritional inequality by only 9%, while the remaining 91% is driven by differences in demand.
https://web.stanford.edu/~diamondr/AllcottDiamondDube_FoodDe...
The most energy and carbon efficient way of providing produce is to grow it where it’s easiest to do so and transport it to where there are consumers who want to buy it.
Added greenery only consumes excess carbon dioxide if you harvest it and bury it in a very, very deep hole, where neither sun nor oxygen can reach it. Otherwise, it only briefly buffers some amount of carbon.
The best argument for extra consumable plants would be if they displaced carbon-positive farming. Then, all that carbon added to the circulation would subtract from emissions growth.