CO2 ventilation breakthrough can turn rooftops into bumper vegetable gardens

Not if the EPA / FDA have something to say about it. My brother lives in Rural Pennsylvania and the local authorities / FDA have been making rounds to homes with larger gardens asking them to "register" or sign agreements that clarify they will never share their produce outside of their own home. Under the guise that the government is providing free "soil testing" to ensure the dirt being used has been properly remediated. This is common in Pennsylvania since historically steel production has tainted almost half the state with heavy metal particulate.

Interesting and worth pursuing. But as a weekend (veg) gardener I'd like to add: more yeild doesn't mean more nutritious and/or tastes good.

For example, no one has ever accused my tomatoes of being similar to the round red things you get at the supermarket. Also, from time to time I'll see something - often on HN - about how less today's veggies are compared to years ago.

The botton line: Instead of trying to invent a new solution why not first take advantage of known (regenerative) farming techniques?

We don't need more...we waste plenty already...we need better.