Farmers know that plants grow best when all
their needs are in balance, not just more and more CO2. Crops also need water, nutrients, correct temperature, pollination, weed & pest control, etc.
Global warming means more droughts and floods. No amount of CO2 will grow corn in a Dust Bowl or under 3 feet of water.
I'd like to see the oil lobbyist who coined this slogan explain the benefits of doubling CO2 to a farmer wiped out by flood or drought. He'd better first swap his Guccis for Nikes . . . and have a good head start!