There's a lot more to the environmental impact of our current farming than just the CO2 though. Water run off is a big pollutant as farms have to spray way more

There's a lot more to the environmental impact of our current farming than just the CO2 though. Water run off is a big pollutant as farms have to spray way more fertilizer onto the ground in order to get the plants to grow than they strictly need, in a hydroponics system for example added nitrogen that doesn't get absorbed would just continue to cycle until it is. In a similar vein current farms' usage of herbicides and pesticides have huge impacts on the environment near and downstream of farms. An indoor farm would require low to no herbicide and pesticide use because the environment is contained and controlled, plus any use would be more easily contained reducing run-off again.