https://www.nature.com/articles/s44284-023-00023-3

My main critique of the article would be that they attempt to account for the carbon from things like sheds and other urban infrastructure that is used in gardening and they compare that to what is required in conventional farms, but they do this without looking at comparable properties/ locations in urban environments that do not garden. If they did they would see that a lot of the infrastructure they are measuring and accounting toward gardening is actually just the infrastructure of an urban environment without a garden. And so a garden is clearly a beneficial use of the resources that are already present. 

For example compare two small lots. Lot A has a shed and is covered in grass. The shed contains the lawn mower, fertilizer used on the grass, pesticides etc. Lot B has a shed too with a lawn mower , pesticides, and fertilizers and some grass but a large garden. 

They both have the same inputs but 1 is producing food the other produces nothing, just maintains the space. 

In this case they are comparing the garden to the farm and concluding the farm requires less inputs per serving. But we can see with the example that if the gardening read this article and then concluded to stop gardening, they would end up still using up the inputs to maintain their grass lot. So switching from garden to grass doesn’t reduce any inputs.